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I I Contents i i 1 Introduction 1 ArcGIS Desktop quick tour............................2 The ArcGIS Desktop framework..................15 2 Geographic Data Management 63 GIS data concepts.......................................64 An overview of geographic data management................................................75 Finding and connecting to data...................85 Previewing data and maps..........................87 Searching for data and maps......................90 Organizing your data with ArcCatalog.........93 Documenting your database with metadata..............................................97 Creating a geodatabase............................102 Creating feature classes and tables..........107 ArcGIS Cornerstones .................................52 Getting help.................................................57 Ensuring spatial data integrity...................113 Ensuring attribute data integrity.................119 Building relationships between features and tables.....................124 Managing raster datasets in a geodatabase.......................................130 Adding specialized datasets to a geodatabase.......................................134 Maximizing the performance of your database........................................146 3 Data Compilation and Editing 151 An overview of data compilation and editing.................................................152 Collecting, importing, and converting GISdata....................................................160 Assigning locations using street addresses or routes.........................165 Starting and managing an edit session.....172 Creating and modifying features................176 Editing connected features........................181 Creating features from a printed or scanned map.........................................190 4 Mapping and Visualization 263 An overview of mapping and visualization........................................264 Adding data to a map................................273 Working with layers...................................277 Setting the map extent and scale..............279 Identifying and locating features................283 Symbolizing data.......................................288 Using attributes to symbolize features.......292 Saving and reusing symbol definitions......296 Creating and storing custom symbols.......298 Adding and editing attribute data...............201 Creating and editing annotation.................207 Creating and editing dimensions...............218 Editing routes and geometric networks.....222 Checking your data for errors....................230 Defining coordinate systems and projecting datasets.............................237 Adjusting and integrating datasets............240 Editing multiuser and distributed geodatabases............................................248 Labeling features.......................................300 Drawing graphics on a map.......................305 Creating a map 'layout...............................309 Adding and arranging map elements.........313 Creating a graph........................................318 Creating a report........................................321 Creating relief maps and perspective views...............................325 Creating dynamic views and animations ...328 Creating a time series animation...............333 5 Geographic Analysis 339 An overview of analysis inArcGIS Desktop.....................................340 Working with tabular data..........................348 Adding fields and calculating attribute values.................352 Joining tables.............................................355 Selecting a subset of features...................360 Working with a selected set.......................365 Extracting a portion of a dataset................369 Overlaying geographic datasets................373 Measuring distances between features.....379 Calculating distance over a surface...........383 Additional Resources for Learning and Using ArcGIS Desktop........................423 Index..........................................................427 Creating paths and corridors.....................386 Allocating areas to centers........................391 Modeling flow.............................................395 Creating raster surfaces............................398 Creating a TIN surface..............................402 Deriving data from an elevation surface....404 Calculating surface volume.......................409 Analyzing visibility......................................412 Analyzing spatial distributions...................416 Identifying patterns and clusters................419 IV V Introduction ArcGIS* Desktop lets you perform the full range of GIS tasks—from geodatabase design and management to data editing, from map query to cartographic production and sophisticated geographic visualization and analysis. It is where the core work of GIS occurs. This book gives you an overview of the ArcGIS Desktop system and shows you how to access the basic functions of the software. This chapter introduces ArcMap™, ArcCatalog™, and AicToolbox™—the basic framework of ArcGIS Desktop—including the structure of each, the functions each performs, and how they're used together. It also provides insight into the underlying design concepts of ArcGIS, and describes where to get help. Chapters 2 through 5 get you started with the specific tasks you'll perform as you use ArcGIS. They're organized around the major functional areas of the software. Each chapter contains an overview and then describes common tasks. The book covers the functions most people will use, plus a number of specialized tasks that you may need for specific applications. It illustrates the various tasks you can perform, shows where to access them in the user interface, and shows how to get started with a particular task using basic or default settings. The tasks presented here, plus many additional tasks and functions, are described in detail in the Desktop Help system (discussed at the end of this chapter). In addition to providing an overview of ArcGIS Desktop, this book can be used as a quick reference to the interface and to common tasks. The book includes functions available in Arclnfo'—the full-function ArcGIS Desktop product—as well as in the Arc View* and ArcEditor™ products (these products are described later in this chapter, as well as in the book What is ArcGIS 9.2?). Using ArcGIS Desktop ArcGIS Desktop quick tour Most of your GIS work will revolve around maps, so exploring a map is a good way to start getting familiar with the software. The following brief tour introduces the two main integrated ArcOIS Desktop applications—ArcMap and ArcCatalog- -along with ArcToolbox. You'll see what they look like and get a sense of what they do. ArcMap is the application you'll use to make maps, edit data, and display the results of your analysis. ArcCatalog is the application you'll use to search for, preview, and manage your geographic data. It's also used to build GIS databases. You'll use the tools in ArcToolbox for processing geographic data—both to create databases and to perform geographic analysis. (The next section, 'The ArcGIS Desktop framework', describes ArcMap, ArcCatalog, and ArcToolbox in more detail, and introduces the ArcGIS Desktop extension products.) ArcGIS uses a standard Windows* interface, for the most part—many buttons will be familiar, and many menu options are found where you'd expect them to be (Open, Save, and Print are found on the File menu, Copy and Paste are on the Edit menu). To begin the tour, select the ArcGIS program group from the Start menu, and select ArcMap. When prompted, click the option to open An existing map, select Browse for maps from the list, and click OK. Browse to the Using_ArcGIS_Desktop folder under the tutorial data distributed with ArcGIS Desktop (the default location is C:\ArcGIS\ArcTutor). Select MexicoPopulationDensity.mxd and click Open. □ * a • ■ > ■ ■ ♦ F™" 3 4 * • n « a a 5» dd3d 4. -get-^ as a ...<......t......J.___i......J........i«.......—3 What you're looking at is a map layout view of the population density of Mexico (in 1990). Each state is color-coded based on the number of people per square mile. The rulers along the top and side of the view show you the size of the map were you to print it—in this case 8.5 x 11 inches. The map displayed on the screen is not a static image of a map (as a printed map would be), but rather is interactive you can change the data that is displayed, change its appearance, change the scale of the map by zooming in or out, and more. Before continuing, if others in your organization will be running through this tour, make a copy of the map. Click the File menu and click Save As. Give the copy a different name— this is the map you'll be working with. 1 • Introduction The table of contents on the left side of the ArcMap window controls which map themes, or layers, are displayed on the map (right now the boxes all have check marks in them indicating all the layers are displayed). Layers higher in the table of contents are displayed on top of lower ones. Click the check box for Rivers to turn it off so it's easier to see population density. Uncheck this box -to turn off the layer The display window (the right-hand panel) is currently showing a layout view. Layout view is where you can see what a map will look like when it's printed. It's also where you add map elements, such as legends, scalebars, titles, and text, and create the map layout. The map is missing a north arrow. Click North Arrow on the Insert menu, select a north arrow from the panel that appears, and click OK. 1 *~ l~-r >ov I>* £..1- aan f" 2 3 Using ArcGIS Desktop 1 • Introduction The north arrow appears on ihe map, surrounded by a box—drag it above the legend at the left side of the map. li it 0 ft " * \"imm 3 tt >»Q * IB? DDDD » j BBa •ro t^jj_---' u D/ajj rftfl irortfi aJTOff hens To print the map. click Print on the File menu. To make sure the whole map fits on the page click Scale Map to fit Printer Paper. You may also need to click Setup lo change the printer paper orientation to landscape. While layout view lets you add and arrange map elements in preparation for printing, much of the initial work with a map—such as which layers you display, and which color schemes and symbols you choose—is done more efficiently in data view. Data view lets you focus exclusively on the map body—the geographic data. To switch to data view, click Data View on the View menu. Switch to Data View •I ■ j MNt I'l I™ 3 Pi.i.H—. I » I " ifn-B 3 J * • □ w »~3 Bit _ -------j! ..^0—jl—f?^-- f... .-.f_.^.„c„ Now the geographic features fill the screen and the map elements no longer appear. However, you can see that the data content from the layout view is all here. If you go back to layout view, all the map elements will still be present. Suppose you want to emphasize the country boundary. In the table of contents, right-click Mexico Bnd to display the context menu for that layer (this menu gives you options for working with the layer) and click Properties. The Layer Properties dialog box gives you options for how the layer is displayed. and diet* P/opertjes 1 • Introduction Using ArcGIS Desktop Click the Symbology lab. and click (he button showing the current symbol. The Symbol Selector d,aloK box appears-** is where you set and modify the symbols you use to draw features such as line colors and widths, area fills, and so on. Set the outline width to 2, then click Outline Color and pick a color that is easier to sec. such as a dark red or brown. Click bore to display Ibe Symbol Selector dialog bo* It would be helpful to show major roads on the map. but they're not in the table of Contents—you have to find the roads dataset and add it to the map. If you knew exactly what the dataset is called and where it is located on disk, you could use the Add button and browse to the file. If you need lo search, though, use ArcCalalog. set tbo width 10 2 . Ihen <** bore 10 display the color palette .laDDncaaiii _ -iiicrDBiiiii The ArcCatalog button Click the ArcCalalog button (or open ArcCatalog from the ArcGIS program group on the Start menu). The ArcCalalog window opens. In the Catalog tree view (the lefl-liand panel navigate to Mexico data under the Using_ ArcGIS Desktop folder. There are two possibilities listed: click mex roads and click the Preview tab. This looks like too many roads lo display for a map of the entire country. -and dick the Preview tab 6 7 Using ArcGIS Desktop 1 • Introduction Now preview the other dataset: roads. By clicking the Metadata tab you can vi. description of the dataset. The metadata confirms that this is major roads. Click me roads dataset W]ien you drag the roads unto the map they're drawn automatically, using a default symbol. Click the roads symbol in the ArcMap table of contents this is a shortcut to the Symbol Selector dialog box. Set the line width to 0.1 and pick a color tor the line from the color palette. (The default symbol color is different each time you add a dataset to a map-so if you added roads again they would draw in a different color. Once you save the map. the symbol specifications are also saved.) and click the Metadata tat To add roads to the map. drag the dataset name from the tree view in ArcCatalog and drop it anywhere on the map display in ArcMap. ■ - y « ■ r— Bjm ii Mm *■! jppr M UMI ■ 9 b> mmt * * JET M • M ib t A- CM ana «ag dalasel tonAnjCoUtoo. . 1° *nUV Ok* to open the Symbol Selector Change Ing tins tvfdfft to 0.1 Each layer has an attribute table that contains the descriptive information associated with each feature. Open the attribute table for the states by right-clicking Stales in the table of contents (to open the context menu I and clicking Open Attribute Table. 8 9 Using ArcGIS Desktop 10 The information in the table can be used to symbolize features (the states are color-coded on the map based on the values in the population density field). You can also explore and query the information in the attribute table as you would in a spreadsheet. You could, for example, get the mean population density for the states, and then find the states having a density greater than the mean. Scroll the table to the right, if necessary, right-click the column heading POP90SQMI (1990 population per square mile), and select Statistics. Right-click the field name ... ArcToolbox includes a wide variety of data management and analysis tools. Expand the Data Management Tools toolbox (by clicking the plus sign next to the toolbox) then expand the Layers and Table Views toolset. Open the Select Layer By Attribute tool by double-clicking it. 3 1 • Introduction f«|w| *™ ) «- 1 ntim ft—nl 9 Pcmgcr 7500732S Bar* CWWrro Men* 1 Pwhjot 27888 1 91 BMClMmi&r 2 PWigon 10547 76! Nrrvt ■ 56£ -Sl*64I boob » SI JC '1 3D *9 k. Sort JKtnJnj F" Sort DrpoMng 3 PtAgon 3C7K386 Jtátca * Ptf,SC. 2110 7B1 *jairMnrlin < řOYBtn "lITIS T¥3 'cuv^Me S Pernor 4645 56! ÚUIMíMXMgi 7'fWígor 8199684 'rttktgo T196S9 XO01 iD5i 3M can 1880366 0000 90 14' «338 30 23J X 336 J fa>d C4taMar,.. r^DMaOmMtiy... ('pSiflor 22961 931 IfcronnMOww 9 PWrflOfi 9291 708 Menco "C °OY»X Si 2 OS 2«Bft0F«IW» 3S4ťfl39 0000 991579* ooot DC 153 DO 1l9i 8235744 0000 30 11426 FreenArítrMíCtAmr R corf hj reteP-í and select Statistics The mean density for the states is about 633 people per square mile. Close the statistics box before going on. l-g—-- - a - a « IE- " - b mm - b rM [EL - QB j iir~ - e u*m ..... Cm* £ in 11 20412 k«™t i«2ě X Sin 2025116922 MU FicqurmcyOMmblMOn 1 7 34071 6923 0 10373 0 13834 9, Use ArcToolbox to find the most densely populated states. Open ArcToolbox by clicking the "Show/Hide ArcToolbox Window" button. The ArcToolbox button Double-click to open —^ Use the drop-down arrow to select States as the Layer Name. Click and select the States layer 11 Using ArcGIS Desktop Click the SQL button to open the Query Builder. Create a query to find states having a density greater than the mean by double-clicking "POP90SQMI" in the Fields box. clicking the "greater than" <>) button, and typing 633. 1 • Introduction If necessary, click the refresh button on the ArcMap window to see the selected states highlighted on the map. At this point, you can close the ArcToolbox window and the attribute table window. ...and type 633 Click OK to close the Query Builder—your expression appears in the box on the Select Layer By Attribute dialog box. When you click OK on the dialog box, a status box appears telling you the command has been completed (you can close this box) and the states having a population density greater than the mean of 633 people per square mile are highlighted in the attribute table. pop mo |j ■<>■<' 2 Ptfygon IQH7 TBI Ntywl 5 P»VWn 1171*7*3 lGMKSOfHOOG 67 3ri77MO0OOO0 li ;x;se= xcecc i 713G59 000000 Ml 396^533 000000 316 -.->•••■ . - »15'9SQOOOMJ 1191 iwa \vmnr. r>;T,m\ The Refresh button To get a closer look, zoom to the selected states by right-clicking States in the table of contents, pointing to Selection, and clicking Zoom To Selected Features. Many of the tools in ArcToolbox are also available through other parts of the interface. (In ArcMap. if you click Select by Attributes on the Selection menu or click Options on the attribute table window and click Select By Attributes, you get a similar query builder dialog box.) ArcToolbox collects all the tools in one place, and gives you a direct, common interface for using them. click Selection ...and clok Zoom To Selected Features 12 13 Using ArcGIS Desktop The map zooms in to the selected states—those with a population density greater than the mean. Ctffl« B ♦ 3 U *- • ° * l a • -n • ■ a _ Psout 1 ' Introduction The ArcGIS Desktop framework When you're done exploring the map. click File and click Exit. When prompted whether to save changes to this map. click No (unless you made a copy of the map as suggested earlier and want to save your changes). The goal of this overview tour was to introduce the core components of ArcGIS Desktop— ArcMap, ArcCatalog. and ArcToolbox—and show how they work together. You'll learn more about each of these in the next sections and in Chapters 2 through 5. Step-by-step tutorials for learning specific parts of the software are found in the Help system (in the -Getting more help' topic under 'Getting Started'). See also "Additional Resources for Learning and Using ArcGIS Desktop' at the end of this book. ArcGIS Desktop is structured around ArcMap. ArcCatalog. and ArcToolbox. This section describes each in more detail, and presents the ArcGIS Desktop extension products. Using these together, you can perform the full range of G1S tasks including geographic data management, data compilation and editing, mapping and visualization, and geographic analysis. ArcMap ArcMap is the central application in ArcGIS Desktop for display and manipulation of geographic data, including mapping, query and selection, and editing. ArcMap lets you create and work with map documents. A map document is composed of data frames, layers, symbols, labels, and graphic objects. ArcMap has two main windows you use to work with map documents: the table of contents window, and the display window. The table of contents lets you specify the geographic data that will be drawn in the display window, and how the data will be drawn. The display window can show either a data view (just the geographic data) or a layout view (a page showing how the data and any map elements—such as legends—are arranged). You'll read more about these windows later in this section. Table of Contents Display Window ■ / i A- «■ J.- Map documents A map document is a file stored on disk. When you start ArcMap you either create a new map document or open an existing one. You add data, change the way the data is displayed, and create new data while working in the map document. When you save a new map document, a filename extension of .mxd is appended to the file name. When you reopen the map document, it looks as it did when you last saved and closed it. 14 15 Using ArcGIS Desktop 1 • Introduction Data frames The container in a map document that holds data is called a data frame. You can think of a data frame as a "window" onto a patch of the earth's surface, scaled down to fit in the ArcMap display. You display and work with the data in a data frame in ground units, such as feet, meters, or kilometers. When you open a new map document, there is one data frame, named Layers. In many cases, your map will only need a single data frame. Complex maps may require several data frames. Data frames are both a way of grouping data in a map document and a way of showing multiple maps on a single layout page. One common use of this is to show different views of the same area. Another common use is to use one data frame to show a map of the area of interest and use another data frame to show a reference map of the wider area. You add data frames to a map document from the Insert menu. G'iri'liii 'i»oa hmil , ,m A layout with two data frames showing two different views of the same area, doth data frames have the same map extent A layout with two data frames showing the area of interest and an inset area reference map. The data frames have different map Layers Each data frame contains one or more layers that you create by adding datasets to a map document (a dataset being a file, or set of files, stored on disk containing GIS data—the basics of GIS data arc discussed in Chapter 2. 'Geographic Data Management"). Each dataset. and hence each layer, contains geographic features of the same type—roads in one layer, rivers in another, county boundaries in a third, and so on. Layers you've created in a map document are stored with the document when you save it. and appear when you reopen the document. A layer contains information about how to display the dataset, but not the data itself. Rather, a layer references the underlying dataset wherever it is stored on disk, so ArcMap doesn't have to store a copy of the data in each map document the dataset is added to. Any changes to the underlying dataset automatically appear in any of the layers created from the dulascl. You can create as many layers from the same dataset as you want in a single map document, in the same or in different data frames. For example, from a dataset of counties you could create one layer that shows the county boundaries with a thick red line and no fill color, and another layer showing the counties color-coded by population. You could add the same counties dataset to another map document to create a layer showing the counties in a solid green color. ~~3 J t-mnv The two layers in the map above—County boundaries and County population—and the layer in the map to the right— County base—were all created from (and point to) the same counties dataset. A- »■ d.- — ' You can also create layers that contain a subset of geographic features from the dataset (this is known as a selected set). For example, from a layer of roads, you could select just the major highways and create a layer showing these. Creating a selected set does not create a new dataset—it only marks the particular features in the underlying dataset as "selected." The la\er created from [he selected sel contains the selection definition, so appeals when you reopen the document. 16 17 Using ArcGIS Desktop A layer in a map document can be saved as a "layer file" (it's named with an extension of .lyr) that can be added to other map documents. A layer file is essentially a map document layer that has been saved to disk. As with a layer on a map. a layer file stores the name and location of the underlying dataset along with the symbol settings for drawing the layer and the definitions of any selected sets (it doesn't store the GIS data). Unlike adding a dataset to a map, when you add a layer file to another map document it appears the same as on the original map document from which it was created—the features are drawn using the same symbols, and any selected sets are implemented. (You can, of course, modify the layer once it's added to the new map document.) You can also export any layer in a map document to create a new dataset. You'd most likely do this if you've created a selected set of features and want to save only those features to a new dataset—perhaps to send to another ArcGIS user, or to use in analysis. Unlike a layer file, the new dataset contains the GIS data, but no symbol settings or selected set definitions. Layers have an associated attribute table that contains descriptive information (obtained from the underlying dataset) about the features in the layer—for example, the name of each park, its size, and which agency maintains it. -U4 < 1 —] - - a »wa la- * t 1 - ■ '■*■-' '- I : ■ ■ '?, ™™ 1 :- IT"" MUKUMNl *J Each layer has an associated attribute table that displays descriptive information about each feature in the layer. Symbols To display geographic data and to better communicate the information on the map. graphic symbols are used—lines, colors, patterns, and so on. Symbols are a set of properties that get applied to a particular feature or geographic object. 1 • Introduction You render the features in a layer by assigning symbols, such as blue lines for rivers and a green color fill tor parks. You can also symbolize features based on descriptive information in the layer attribute table. For example, you could symbolize parcels by assigning a color to each landuse code: all residential parcels yellow, all commercial parcels red. all vacant parcels gray. Landuse can be mapped by assigning a different color symbol to each landuse category—parcels are drawn using the color for their assigned landuse value-When you add data to create a layer, or when you draw a graphic object, a default symbol is used. You can modify the properties of the default symbol or apply another predefined symbol from a palette (and then modify it if necessary). - m - p5:. umm ■■■■ :£±3::: You choose symbols from the Symbol Selector dialog box. You can use a symbol as is, or modify it. You can add symbols to the palette by opening additional styles. ArcMap includes a number of styles. You can access these—and the symbols they contain—when you're making a map or when you're creating your own symbols. 18 19 Using ArcGIS Desktop 1 • Introduction Predefined symbols are stored in styles. A style is a folder that contains other folders, one for each symbol type—all the line symbols in one folder, all the color symbols in another, all the marker symbols in a third. Many industries, such as forestry or real estate, use standard symbols on their maps, so styles are often specific to a particular industry. ArcMap provides a number of styles for various industries. You can save any symbols you modify in an existing or new style. You can also create new symbols entirely from scratch and store them in a style. • ■ * o. Wo can. 3 Q a li*l±l±l filSI • • : lol»lol®i@laW*l*l»lTL You access styles—end the symbols they contain—via the Style Manager. You can modify any of the existing symbols, or create your own, using the Symbol Property Editor. Labels Labels are used to identify geographic features on your map. such as labeling streets with their name. There are several ways to create labels in ArcMap: • You can label features with their name or other information from the layer attribute table by specifying a field in the table. Text labels are placed automatically and can't be moved or edited individually. • You can create annotation features. Annotation features are usually associated with individual geographic features and can be placed and edited individually. When you move a feature, the annotation automatically moves with it. Annotation can also be stored as a separate dataset and added to different maps. • You can label features using graphic text. Graphic text is placed and edited individually, but is not linked to features. It is often used to label one feature, or a few. Graphic text is stored only with the map document in which it was created. 20 Feature labels /street names in this map) are creeled lor each feature. They're placed automatically and can't be edited individually. Graphic text is used to quickly label individual features. It can also be used to create labels lor general locations not represented by specific features, such as the civic center area shown on this map. Graphic objects Graphic objects, such as circles or boxes, are used to highlight the data that's displayed in the map document. Graphic objects, along with graphic text, are also used to create map elements, such as tttles. neatlines. legends, scalebars, and north arrows, that describe the information on your map. aaaaoos . -k» j a b a The title, north arrow, scatebar, and legend are all composed of graphic objects, as is the blue circle on the map 21 Using ArcGIS Desktop 1 ' Introduction The ArcMap interface The ArcMap interface consists of the two main windows—the table of contents and display windows—along with a number of standard and specialized toolbars and menus. The table of contents The table of contents lists the data frames and layers in the map document, and shows you the current symbols for each layer. Use the check boxes to tum layers on and off. Drag layers up or down in the table of contents to change the drawing order (layers higher in the list draw on top). Click and drag a layer to change the order. The table of contents is also where you control how layers are drawn, via context menus (right-click a layer name to display the menu). You can change the colors and patterns used to draw features, label features, and more. The tabs at the bottom of the table of contents window present different views of the layer list. The Display tab is the default, and is the one you'll use when displaying and querying data—it shows a simple list of all the layers, organized by data frame (group layers are used to manage several layers as a unit). The Source tab is useful when you're editing data- it shows the layers organized by where their underlying dataset is stored (either in a folder or a geodatabase). It also lets you see other nonlayer data stored with your map. such as tables not associated with a geographic dataset. The Selection tab gives you an overview of selected subsets of data that are currently active, and lets you set selectable layers. Data Irame Geodatabase - The Display tab The Source tab Checked box indicates layer available for selection 1 ■ *— Bold indicates layer having —|— H • a selected subset The Selection tab The display window The display window displays the layers and graphic objects in the map document. It has two views that you switch between: data view and layout view. Data view shows you one data frame at a time, including the currently displayed layers in that frame, along with any labels or graphic objects drawn inside the data frame. In data view, the display window is the data frame—the layers in the active data frame appear in the window. Layout view shows you all the data frames in the map document and their contents on a layout page along with map elements you've created, such as titles. legends, and scalebars. In layout view, the data frame is embedded on the page—the frame itself is treated as a graphic element, as reflected by the context menu for the data frame on the layout page. It can be moved, resized, and so on. MM > FH»* 3 J. Data view is mainly where you do map display, query, and editing. You set the scale and map extent to control the geographic area that's displayed. You can interactively zoom in and out and pan the data (you can also set the map scale explicitly, in the scale window). You work with the contents of the data frame in ground units, such as feet or meters. Layout view is where you compose page layouts for printing and publishing. You work with the layout in page units—usually inches or centimeters. Layout view activates tools for navigating around the page, for adding standard map elements, such as legends and scale bars, and for arranging the map data and map elements on the page. Simple map elements, such as titles and neatlines. are associated with the map page. Other map elements, such as legends and scalebars, are associated with a data frame and are dynamic—they change to reflect the layers and the map scale displayed in the data frame. 23 22 Using ArcGIS Desktop 1 • Introduction When in layout c ^ai**1' view, you can add map elements from the Insert menu. While in layout view you can still work with the data that's displayed in a data frame just as you do in data view—zoom in and out. pan. tum layers on and off, change symbols, and even edit the data. Only one data frame is active at a time. The active data frame appears in bold in the table of contents. When you add layers to the map they're added to the active data frame. In layout view, the active data frame is outlined with a dashed box—you need to make a data frame active before you can work with the data in the frame. To make a data frame active, click it in layout view or right-click the data frame name in the table of contents and select Activate from the context menu. im »•» » n** w «- we «. 4» *• f * \ ~ m «iAA»nw«* • o ft —a J ' t~.|nM-|.^.| tt, AfcCafa/og Jefs you preview datasets as thumbnails. The Catalog tree shows the workspace structure and contents. Using ArcCatalog to compile data In addition to using ArcCatalog to organize, preview, and document data, you use ArcCatalog to implement database designs and compile GIS data. ArcCatalog is where youTI import datasets from other GIS formats. Use ArcCatalog to Import datasets. 33 Using ArcGIS Desktop 1 • Introduction ArcCatalog also lets you prepare datasets for editing and updating—you can set up rules so that edits to one feature class are reflected in another or that moving one feature moves associated or connected features; you can also define additional fields before adding attribute values when editing in ArcMap. You may also use ArcCatalog to assign the spatial reference for a dataset, so its coordinate system is defined. e« e« s— *• i"« fc, 4 * * p * I-- trv* tor—I ofis-m*"!**! I c-.Im 1 * « E, Arc Toolbox Much of your CIS work will involve using ArcMap and ArcCatalog to manage, display. and query geographic data. A good deal of your work will also involve processing geographic data to create new datasets, known as geoprocessing. Geoprocessing is used in virtually all phases of GIS—for data automation, compilation, and data management: analysis and modeling; and for advanced cartography. A typical geoprocessing operation takes one or more input datasets. performs an operation, and returns the result of the operation as an output dataset. The Union tool, for example, combines features from separate datasets into a single dataset. Inputs to Union Output from Union Use the Properties dialog box in ArcCatalog (right-click a dataset and click Properties} to specify the spatial reference for a dataset or add fields to the dataset You also use ArcCatalog to create new (empty) datasets before creating the geographic features themselves in the datasets (by importing or by editing in ArcMap). ArcCatalog lets you define parameters and rules to ensure data integrity for your database. Right-clicking an entry in the tree and clicking New displays the appropriate options for creating new databases or datasets. or for creating rules for the database. Right-click a Catalog tree entry to begin defining new databases, datasets, or rules for ensuring data integrity. Using ArcCatalog to build databases and compile GIS data is discussed in Chapter 2. •Geographic Data Management", and Chapter 3. 'Data Compilation and Editing". Landparcels Soiltypes Land parcels and soil types There are geoprocessing functions for spatial analysis operations, for converting data from one format to another, for simple data management operations such as copying datasets, for data integration operations such as appending map sheets, and many other operations. These geoprocessing functions are collected as tools in ArcToolbox, grouped by category in toolboxes and toolsets. Some of these same functions can also be accessed through toolbars, menus, and dialog boxes in ArcMap and ArcCatalog. Toolbox -Toolset - 11 ArcTodbox t% Analysts tods -' t$ E*tract /■ Op /• Sded ^Sf* /■ Table Select Overlay Proximity StetJsttcs Cartography Tods » ^ Conversion Tools H B Data Management Tods r tip GeoOodrng Tools * ^ Lneat Referencng Tods • % Spatial Statist.;! Tods Fevtrtes j ln.de» | Search | Additional geoprocessing toolsets come with many of the ArcGIS extensions (described later in this chapter), such as ArcGIS Spatial Analyst, which includes raster modeling tools, and ArcGIS 3D Analyst™, which includes terrain analysis tools, ArcGIS Geostatistical Analyst adds kriging and surface interpolation tools. When the extensions are installed, the tools appear as new toolsets in ArcToolbox. Some may also appear in menus or toolbars in ArcMap or ArcCatalog. 34 35 Using ArcGfS Desktop 1 ■ Introduction Opening the Slope tool from the Surface Toolbox opens a dialog box that prompts you for the tool parameters. The Slope tool can also be run from a similar dialog box opened from the Spatial Analyst toolbar. HE} 3 4 II IC Not all ArcToolbox tools create new datasets (and thereby perform geoprocessmg. strictly speaking), but all allow you to at least manage or manipulate your data in some manner. Using ArcToolbox To open ArcToolbox. click the Show/Hide ArcToolbox Window button on the ArcMap or ArcCatalog toolbar, or click ArcToolbox in the Window menu. The ArcToolbox window is initially docked in the ArcMap or ArcCatalog window. You can drag it to dock it along any edge or have it float as a separate window. Th& ArcToolbox button When you open ArcToolbox click the plus sign next to a toolbox to see the available toolsets, and open a toolset to see the individual tools. You can also browse an alphabetical list or search for a tool by name (click the tabs at the bottom of the ArcToolbox window). Once you find the tool you want, use Locate to display the tool in the toolset—this is useful since you can see related tools in the toolset. *> GrcftUral I Df*ty k Otabmca P Comdor ^ CuddMn Oncbon /(uddifiDawa _ PathDttara > P4t*MUnoj«iocjt ^ PrtOKtraBadiL TWntf»kfv-cirOlof«fJ Drae m EdtS^atjf. Iia! EdtTINIM E 7-10,« I EiMlm T»» n the naejfl Is HWti for PmCwn* Search for tool in ArcToolbox using the functional list, an alphabetical index, or by searching for a keyword. You run a tool from any of the tabs by double-clicking it (or right-clicking and clicking Open) to display a tool dialog box. The dialog box prompts you for the input data and output dataset, as well as any required or optional parameters. The required parameters are indicated by a green dot. Once you enter a valid parameter, the dot disappears. If the input you enter isn*t valid—for example, if a dataset you enter doesn't exist—the dot turns red If you've opened ArcToolbox from ArcMap. you can select the input data from the layers that are currently displayed on your map. using the drop-down menu on the dialog box. For optional parameters, ArcGIS often supplies default values, which you can use or change. Click OK to run the tool—a Status window shows you the progress of the tool and tells you whether the process completed successfully. >r 'riVi wurca data ~3 *| ~ -I Outout dtrtefcon ri Running a function from ArcToolbox opens a dialog box. v.re II: EueCistue* Hvexa 'Ci\um( wh ttvcUi StOtt Tin*: Hon lay 09 21:07:17 200! Completed IucBllttAC*., When you run the tool, a status window appears—it tells you the progress of the operation and notifies you when it completes. 36 37 Using ArcGIS Desktop 1 • Introduction You can run any of the functions that appear as tools in Arc Toolbox from a command line. This is an efficient way to run a function if you're already familiar with it—you type the function name, the input and output, and the parameters on a single line. To open the Command Line window, click the button on the ArcMap or ArcCatalog toolbar, or click Command Line on the Window menu. As with ArcToolbox. the Command Line window can float or be docked inside the ArcMap or ArcCatalog window. The Command Line button If you're working in ArcMap. results produced from running tools via the dialog box or command line will be added to your display by default (you can turn this off). In some cases, the result of a function is simply a chart that appears in its own window or a statistical value that appears in the status results window. Customizing the toolbox You can create your own toolbox and add tools from other toolboxes—for example, you might collect tools you use often into one toolbox for easy access. To create a new toolbox, right-click anywhere in the ArcToolbox window and click New Toolbox. You can create toolsets inside a toolbox to further organize your tools (right-click the toolbox name, click New, and click Toolset). Click the Show/Hide Command Line Window button on the ArcMap toolbar; when you start typing in the window, an alphabetical list of functions is displayed. You type the command in the upper half of the window. As you type, the command usage is displayed. Press Enter to run the command—the status appears in the lower half of the window. a sat * * 3 - - ft ~3F~3 ■ i i a- —• The command usage and other prompts are displayed as you type BOB •■' t to*** To* ftddracfaa.-b lar-cff apTrr look — fco»***!«* — k tJtoattttttiä Anitr* tlnwMiwnxjtq LcariSfttti^ * - 4» 5e*ad ArWrtt loot* — • t% 5p*l«l SHOOK* T«* -J •1 iiT itwllrdft. 1 Sa«ch| To add a tool, right-click the toolbox or toolset name, click Add. and click Tool. In the dialog box that appears use the check boxes to specify which existing tools to add. h OaoAMBttLSJ Anrtyo Tod « RatWftnOhg ■ tr. J V«« "W-o look / So« tP* : * Do y... In addition to adding existing tools to a toolset, you can add your own custom tools from type libraries, executable programs, and ActiveX controls. Use Add From File on the Add Tool dialog box. 38 39 Using ArcGIS Desktop 1 • Introduction Setting the geoprocessing environments Every tool dialog box has an Environments button. When geoprocessing tools are run. default environment settings set for the application are applied to all applicable tools. Examples of environment settings include the current workspace from which to take input data and place resulting datasets. or the geographic extent to apply to results. These settings j can be changed in the Environment Settings dialog box. mť-irř É 4 -H4 ~ d ZiZL ZJfV I »-"-■ I Automating multistep processes In many instances, the geoprocessing work that must be done is repetitive, involving a large number of datasets or large datasets with numerous records. In addition, many geoprocessing tasks involve a multistep process—you use the result of one function as input to the next. Complex tasks may involve many such operations. ArcGIS Desktop provides two ways to automate repetitive or multistep geoprocessing: scripts and models. Scripts are useful for batch processing multiple inputs, such as when converting multiple datasets to a different format. Models provide a graphic way of creating and expressing a multistep process or method, such as when performing spatial analysis. The scripts and models you create become tools in a toolbox (often a custom toolbox you create) and are run just like other tools—either through a dialog box or command line, or embedded in yet other scripts or models. Creating a script Scripts can be written in any Component Object Model (COM)-compliant scripting language, such as Python1, JScript*. or VBScript™, or they can be ARC Macro Language (AML™) scripts or executable files. Any of the functions in Arc Toolbox can be included in a script. In fact, to include a function in a script you type it the same way you would if you were running it interactively in the Command Line w indow—the usage is the same. Functions can be embedded in other script statements including branching and iterative statements. 15 Scripts can be run from within their scripting application, or they can be added to a toolbox and run like any other tool from a dialog box, the command line, a model, or another script. To add a script, right-click a toolbox or toolset, click Add, and click Script. This opens the Add Script dialog box. which prompts you for a name for the script and other descriptive information, as well as the name of the file containing the script. You also specify any required or optional input parameters. ÍX> Andnt roofs AraJywIoob k C«tC-JJCl>r loofe \ Corr-erscn look \ Covvapa Tot* ) uKKodng lock I UHXmH ArvM Torts 1 Lrai Kafsrancng I Ml í SMCM = %1 Cow 40 41 Using ArcGIS Desktop 1 • Introduction When you run the script in Arc Toolbox—the same way as with any other tool—a dialog box opens that prompts the user for the input and output datasets and any parameters. flgj »I ::|DI"|::| ®l»l«l-| >l Output buffer around streams This simple model contains one process—the Buffer tool is used to create an output of buffer zones that are a certain distance around the input streams. Add scripts to toolboxes and run them by supplying values tor parameters. Creating a model Models arc created within a toolbox or toolset in ArcToolbox—click the toolbox or toolset, click New. and click Model to open the ModelBuilder™ window. You can drag tools from ArcToolbox. and datasets from ArcMap or ArcCatalog, onto a model and connect these to create an ordered sequence of steps to perform GIS tasks. Use the buttons to connect datasets to tools, and to automatically align the model elements. Double-click a tool to open its dialog box and define the parameters (or right-click the tool and click Open). To build the model, drag and drop tools from ArcToolbox and datasets from ArcCatalog onto the ModelBuilder window. Then connect them in sequence. ^fe«4Ato Copy ■MR ja») Hl ai mm »I i:ia;:|:tl QlftlaH k\A ► ! Nodal E* Wido- Hr* SB » ! IM ff MOTH... Many GIS tasks—especially analysis tasks—are not individual operations but sequences where the result of one operation becomes input to the next. While you could run the individual operations (tools) one at a time. ModelBuilder gives you a way to connect the operations using a flow diagram and then run all the operations in sequence, at one time. The basic structure of a model is an input dataset connected to a function producing an output dataset. Click the Run button to nun the model. A window opens that displays the status of each process. Double-click a tool in the model to open its dialog box, then enter the parameters. jpjg »e*ct [maw*; r.i-'-....- 42 43 Using ArcCIS Desktop 1 • Introduction The parameters you define—including the domain codes, in this example—are stored with! the model, so if you want to change them and re-create the domain, you just edit the model! and rerun it. Or. you can copy the model and modify it. Once the model is constructed, youl run it in the ModelBuilder window, or from within ArcToolbox as with any other tool. ft. a* « » * t\ W « 4 • 0 t. 'Sr.,. »655 1 i - m hi * imm »\ ■iBaiai aimi.i >i.»i >i Right-click a mode! in the Catalog tree and click Edit to display it in the ModelBuilder window and make changes. r1 Double-click a tool in the \ model to open its dialog box and display the current parameters. You can connect multiple inputs, Functions, and outputs to create quite complex models. Models can include scripts, and even other models. Ml 4 ifiS *J HOililU iMHHM Aid ±1 Gfiaiealcher Habitat Suitability Scripts and models are a good way to save your methods and procedures. A model can be exported as a graphic file or to a script for additional editing or for sharing with other GIS users. You export a model to a script from the Model menu on the ModelBuilder window. - 44 45 Using ArcGIS Desktop ArcGIS Desktop ArcGIS Desktop extensions add specialized functionality for data compilation, cartograph Extensions production, and advanced geographic analysis. Any of the extension products can be starte from either ArcCatalog or ArcMap—you first need to enable the extension from the Tools menu, and then open the extension's toolbar from the View menu (click View and point to Toolbars). Hal B» 6* *- ton □ -» a • * * 11 J *-»a v B 0* B Sp***n4* B ti^flAn^ b: lafc ro, ufse irakskig and X w 1][«~3 I ■ A- J.- To enable an extension, click Extensions on the Tools menu and check the extension you want to enable. 1 • Introduction Here is a brief description of each extension product. The licenses for the products are sold separately, except as noted below. Data Compilation Extensions • ArcSctmfor AitGIS is used to generate data from scanned maps and manuscripts. It vectorizes features from raster data and includes integrated raster-vector editing tools. A complimentary ArcScan™ license is included w ith ArcEditor and Arclnfo. 3 J *■ w :: «•*» IP t • » ii f % o 1 V- ^ 020 ? 021 " r Creating parcel features from a scanned map Then open the extension's toolbar from the View menu Some extensions add tools to Arc Toolbox; some add a toolbar to ArcMap or ArcCatalog: and some do both. ArcGIS Darn Interoperability adds the ability to directly read, transform, and export more than sixty common GIS data formats. It also includes tools to build converters for complex or specialized data formats. ■ r- OOKd Converting data between fonnats 46 47 Using ArcGIS Desktop 1 • Introduction ArcGIS Schematics generates database-driven schematic diagrams of GIS networks, such as electrical, water, or telecommunications networks. It lets you create multiple schematic representations of a network and place schematic views on maps and in documents. Creating a schematic diagram for a physical network Cartographic Production Extensions * Maplex for ArcGIS adds advanced label placement for cartographic production and simplifies the labor-intensive process of placing map text. It detects labels that overlap and automatically moves them, and includes tools for custom label placement. A complimentary Maplex™ license is included with Arclnfo. Placing labels for production of a utility network map ArcGIS Publisher is used to publish data and maps for use with ArcReader™. It enables the creation of a published map file (PMF) format for any ArcMap document. PMFs are used in ArcReader, and allow you to freely share your ArcMap documents with any number of users. Publishing a map as a PMF file for display in ArcReader Geographic Analysis Extensions • ArcGIS Spatial Analyst provides advanced modeling and analysis for raster datasets. including terrain analysis (creating shaded relief, slope, and aspect from a Digital Elevation Model), creation of distance and cost surfaces, and raster overlay. Selecting the best location for a business 48 49 Using ArcGIS Desktop 1 • Introduction ArcGIS 3D Analyst enables visualization and analysis of surface data, including creation of perspective views. It provides advanced tools for three-dimensional modeling, such as cut-fill, line of sight, and terrain modeling. Creating a perspective vievi ArcGIS Geoslatistical Analyst provides statistical tools for predicting values across a surface from a set of sample points. It includes exploratory spatial data analysis tools for identifying outliers, trends, and spatial autocorrelation. ArcGIS Network Analyst is used for transportation network analysis. It allows you to find the shortest path between two points, allocate resources to a center, or find the most efficient route between several stops. Finding the best route through a set of stops ArcGIS Tracking Analyst allows you to view and analyze temporal data—you can track feature movement through time (such as the location of a hurricane over the course of a week) and track attribute values for features over time (such as population for a county over several decades). It also lets you create time-based animations. Creating a continuous surface of toxic exposure from a set of sample points OCT- VI • • •—-- • a .».„..-. * * ■■■ ■ ■ * - * V,,.*** . • *™ s h Ek ........... "-I'-- .......- ja—i- " " ~ amy- ......- □ A - MUhMUi Tracking the strength and location of a hurricane 50 51 Using ArcGIS Desktop 1 • Introduction ArcGIS Cornerstones There is a set of cornerstones underlying the design of ArcGIS. Understanding these cornerstones will help you understand how ArcGIS is built and. in tum. how to use the software effectively. A tiered product ArcGIS Desktop is sold as three software products, each providing a higher level of Structure functionality. • The first level of functionality, called Arc View, provides mapping, data use. and analysis tools along with simple editing and geoprocessing. • The second level, called ArcEditor. includes all the functionality of ArcView and adds| advanced geographic data editing capabilities. • The highest level of functionality is Arclnfo. the full-function, flagship GIS Desktop product. It includes the functionality of both ArcView and ArcEditor. and extends it with tools for advanced data management and analysis. It also includes the legacy applications for Arclnfo Workstation (including ArcPlot™. ArcEdit™. andAML). The reason for the three products is that not everybody needs the full functionality of Arclnfo—at least initially. Your organization may have purchased one of the products, or some combination—for example, one Arclnfo license for advanced processing, and three ArcView licenses for people who mainly need to display and query geographic data. All three products include ArcMap. ArcCatalog, and ArcToolbox. The available functionality of each depends on the product you're using. For example, if you buy ArcView you get about 80 tools within ArcToolbox; ArcEdit provides over 90 tools; and if you buy Arclnfo you get about 250 tools within ArcToolbox. An extendable ArcGIS Desktop is designed around core functionality that can be extended for specialized product applications. The core functionality included in ArcMap, ArcCatalog, and ArcToolbox covers the tasks that the vast majority of users will need at some point in their GIS work. Because of the range of GIS applications and tasks, though, some users may never need the advanced functionality available in ArcGIS Desktop for particular tasks. For example, a water utility that uses GIS to build and maintain a database of its pipes and pumps, and perhaps its customers, will likely never need to use advanced raster analysis capabilities. Conversely, a forest research lab will likely never need to include schematic drawings of a utility network in its GIS. To allow for flexibility in building your GIS, ArcGIS Desktop includes extension products (described earlier) that provide advanced capability for data compilation, cartographic production, and advanced geographic analysis. That allows you to buy and install only the advanced functionality you'll use. ArcGIS Desktop provides a flexible user interface that allows you to perform many of the same tasks in different ways, depending on the type of work you're doing and the framework you're using. For example, you can add a field to a table in either ArcCatalog. ArcMap. or ArcToolbox. That allows you to perform this common task whether you're using ArcCatalog to add a field while building a new dataset, you're using ArcMap to add a new field and calculate attribute values while doing analysis, or you need to add a field to a dataset while using ArcToolbox to build a model. Adding a held from an attribute table in ArcMap. 52 Adding a field to a table in ArcCatalog using the Properties dialog box. Adding a Held using an ArcToolbox dialog box. -3 4 53 Using ArcGIS Desktop 1 • Introduction Similarly, the interface often provides defaults you can use for particular functions. You ca accept the defaults, or modify them. For example, when specif; iiiLi what symbols to use to draw features, such as the color and size you want points representing buildings to appear on your map. you can: • Use the default symbol assigned when the data is added to the map • Change some basic properties of the symbol, such as color and size • Access and modify any of the properties that make up the current symbol • Create your own symbol from scratch by defining the various properties f* e* W" v ■ j e * * * "~3 4 *-%G W You can use the default symbol... r>l= I □ • a- i-'. [«; 4631« 7? l*fui:e, s*rv taarjon 1 Oottoo*' • ■ QfCM ? s»iot»: °- Mi ,,. modify some basic properties of the default symbol or choose another predefined symbol using the Symbol Selector... ■ : %» I- ♦J xj t] ♦) •Iii ArcGIS Desktop provides a range of interface options that allow users at different skill levels to work efficiently—from wizards and dialog boxes to a command line interface. For example, tools in ArcToolbox can be run using a dialog box that prompts for inputs— helpful for less experienced users—or can be entered on a command line, a more direct way for advanced users to run the tools. ft Aruryas TOCd I ft ExVKt - ft Overlay ^ Erase A Intersect p Symmetrical qrfe-qx ^Lpdate - ft PrommHy . ft SDKOCS Q^^QQ ft Cancer aphy Tc 3*1 JüJ ♦] Chat» Talwancfl (npirormi; Upi HtMM (Dpi end p*rceLs_polnfon; f loo.a_pol.raoQ Ilood_parcel ILL 0.1 au>a| Running the Union tool using a dialog box. Running the Union tool using the command line. You can customize the interface, specifying which menus to display and which buttons to include, for example. JjXJ Tod") I Cormrt), J Ootm | IE JJJSt tin** XVw —( Advanced E* Took 7 Mo-Ay Ink M Jj Dodrrmn Lr*l - r;1— l ir Ooon Co-nod Pjni Fit The ArcGIS Desktop interface is customizable (click Customize from the Tools menu in ArcMap or ArcCatalog) Use the Toolbars tab to specify which toolbars to display, by default. Use the Commands tab to add buttons (commands) to the various toolbars. ...or. you can access and modify all the properties of the symbol or create symbols from scratch using the Symbol Property Editor. 54 55 Using ArcGIS Desktop 1 • Introduction Flexible data Another cornerstone of ArcGIS Desktop is its ability to access GIS data in any format and support to support a range of database configurations. ArcGIS is designed to work with just about every type of geographic data, from a broad array of sources. Some data formats ArcGIS can read directly, such as geodatabase datasets. shapefiles. coverages, and many raster formats. Data in other GIS formats must be converted to an ArcGIS format before you can display and work with the data—ArcGIS Desktop includes converters for many standard GIS formats. Some data, such as CAD data, can be read and displayed by ArcGIS Desktop, but must be converted to an ArcGIS format to take advantage of the full functionality of the software. ArcGIS Desktop also lets you set up databases that will meet the needs of one person, a small department or workgroup, or an enterprise that requires that many people to be able to access and edit the database concurrently. If you already use a commercial DBMS—or need your GIS to work with such a system—you can take advantage of this by creating ArcSDE* geodatabases. Types of geographic data and how to manage data are discussed in Chapter 2. 'Geographic Data Management'. A generic ArcGIS Desktop was designed to be used across a range of disciplines for a huge variety application of tasks. It is not industry or application specific. The software provides a comprehensive approach set of tools and functions that users combine in the way that best addresses the task at hand. Many users customize the application toolbars and menus to reflect the tasks and workflows they perform most frequently. ArcGIS Desktop can also be used with other ArcGIS applications in a way that allows GIS to be available on different hardware platforms and for a range of GIS users—from the general public to casual GIS users to GIS specialists. For example, maps created in ArcMapj can be published using the ArcGIS Publisher extension. The maps can be distributed on CD/DVD or over the Internet and read by non-GIS users using ArcReader™. a simple, standalone map display software application. The book What is ArcGIS? describes the complete ArcGIS system and how ArcGIS Desktop can be used w ith other ArcGIS applications to publish data and maps on the Internet, used by people throughout an organization to access a centralized GIS database, orl used in conjunction with handheld devices to collect and update data in the field. Getting help Desktop Help Chapters 2 through 5 describe the basics of a number of common tasks performed in ArcGIS Desktop. More information on these and other tasks is available in the ArcGIS Desktop Help system. The Help system contains both task-based (step-by-step) and conceptual information, and includes a GIS dictionary. There are also several online sources of help available. Help can be accessed from an ArcGIS application (ArcMap or ArcCatalog) via the Help menu on the Main menu, from the Start Programs menu, or by pressing the Fl key on the keyboard. The Help viewer contains a navigation pane—with Contents, Index, Favorites, and Search tabs—and a topic pane for viewing Help topics. n 3 & ^gis Welcome to ArcGIS Desktop Help About ArcGIS Desktop artCIS DMttoo nduó-n * cum ¥ "agriWi tootaxxns that alt™ ,ou to wform GIS usfct. from wnoto to *J.*no»d, mdudng macemg, 9»oor»rVnc *n*fus, data toong and eomoMfton, aau NnigiiiMt, "tvHMi, and gcoerttuwng • ***™-<> ■■'■ar.'tfip'- .icr AreM^ ■ SMI rw^^nt j,^**™ • Ea^fc t-.n rim ro-aťaccn • TbLMJOmttViia Getting Started with ArcGIS Desktop g: BMW 015 COnctMt. including mapi. CHnlnM (íttwní and raonjfarong and working wOi gregrapnic Use the Contents to look up general topics. Conceptual topics in the contents list are indicated by a page icon. Task-based topics include step-by-step instructions and tips for performing specific tasks. They're indicated by an icon showing a page with a numbered list. Some of these topics also have short, animated tutorials available. You can scroll through the Index or search by entering keywords that identify your task. The Favorites tab lets you keep a list of often-visited topics. Use the Search tab to enter keywords, phrases, or complete sentences. Once you've entered your search, click the Ask button. The results are ranked and provide links to the topic. 56 57 Using ArcGIS Desktop The Help system also lets you get information about the burtons and menu commands you see on the interface. When you position the mouse pointer over a button for a second or two, the button's name pops up (this can be turned on or off on the Options tab of the Customize dialog box). After clicking the What's This? button on the standard toolbar, you can click any button or menu option to display a description of it. Select By Location.,._ Select By Attributes Select features from one of the layers in the active data frame by specifying a query based on the attributes of its features. Set Selectable Layers.. £3 Sear Selected Features interactive Selection Method ► Qpbons... When you click the Help button in the upper-right comer of a dialog box, then click an item, a description is displayed. Some dialog boxes also have a Help button on the bottom; clicking it opens a Help topic with detailed information about the particular task. n eda wM r Sector, Octon* 4 For tijrrst, if the layer contain* polygon faatun •fid TOU would ttinrri to be til lad in mHtt\ a Dammlar color when the* ara lalacted, dick the symbol to display »* Symbol Selector, and then diooie th» fail symbol rou want to Ufa. 1 • Introduction All ArcToolbox tools have associated help. The Show/Hide Help button on the tool dialog box displays (or hides) a Help panel with a description of the tool and information about the tool parameters. Clicking the Help button at the top of the panel takes you to the topic in the Desktop Help system where you'll find complete information about the tool. Click here to open the tools topic in the Desktop Help system -a + i 3 !M Incur Ft* jttt Features or portion of balms common io at layers anoVtt 1»tun cletsti be nraan to ina •utpal Show or hide the Help panel Intersect (Analysis) Cwrtoutes agaonwmi ittsnacbon ofttia Input Faahrar Faaturai or cotijnj o> featum *rf*ti o.»n*o m aft 'ayers arvi/o- ■aatura castas win ba wnoan to cia Outout Faatun ciai* i mum mora atom |aj| Ipt«"*«-n -<■" ^ 58 59 Using ArcGIS Desktop 1 • Introduction Online Help In addition to the Desktop Help System, there are several online resources for getting help I with the software. These can also be accessed from the Help menu. Online resources, including Desktop Help Online, a GIS Dictionary, the ESRI Support Center, training resources, and developer support are available from the Help menu. Desktop Help online The entire Desktop Help system is also available online. The online version features links j to common tasks and to specific applications. 9 .GIS 9.2 Desktop Help 1_____ ■■■ Welcome to ArcGIS 9.2 Desktop Help ESRI Support Center This online site provides users with information and help for all of ESRI's software products. You can access it directly from http://sttpport.esri.com, or you can launch it from the Help menu in ArcGIS. The site includes: • The Knowledge Base, which lets you search ESRI's database of technical articles, white papers, system requirements, and product documentation. • Downloads of the latest software updates, service packs, samples, user-contributed ArcScriptssw. data models, geoprocessing models and scripts, and evaluation software. • User forums for ESRJ's community of GIS professionals to browse and post focused questions, or actively help others. EH Developer Help The ESRI* Developer Network (EDNSM) at edn.esri.com provides information about creating your own user interfaces, tools, and special applications. This site contains sample code, technical documents, downloads of developer tools and add-ins. and discussion forums for ESRJ's developer community. ."íl EDN WW***"* -. Welcome to EDN... 60 61 Geographic I Management GIS data concepts • 64 An overview of geographic data management • 75 Finding and connecting to data • 85 Establishing a data connection Database and server connections Previewing data and maps • 87 Previewing what's in a folder or geodatabase Previewing a feature's geography or attributes Reviewing a dataset's characteristics Creating a thumbnail Searching for data and maps • 90 Organizing your data with ArcCatalog • 93 Creating a new workspace Managing workspaces and datasets Exploring an item's properties Managing the ArcCatalog display Documenting your database with metadata • 97 Selecting the metadata stylesheet Printing metadata Editing metadata documentation Importing and exporting metadata Creating a geodatabase • 102 Creating a geodatabase using ArcCatalog tools Creating a geodatabase by copying a template Creating feature classes and tables • 107 Creating a feature class Creating a standalone table Specifying additional fields Modifying a feature class or table definition Ensuring spatial data integrity • 113 Creating a feature dataset Getting data into a feature dataset Creating a geodatabase topology Managing a topology Ensuring attribute data integrity • 119 Assigning default values to fields Using domains to ensure valid attribute values Using subtypes to assign default values and domains Building relationships between features and tables • 124 Creating a relationship class Specifying the number of allowed linked records Managing a relationship class Accessing table relationships in ArcMap Managing raster datasets in a geodatabase • 130 Loading rasters into a geodatabase Creating a raster catalog Adding specialized datasets to a geodatabase -134 Creating a terrain dataset for surface modeling Creating a network dataset for transportation applications Creating a geometric network for utilities applications Creating an address locator for geocoding Creating a route dataset for linear referencing Maximizing the performance of your database • 146 Defining or modifying a spatial index Creating an attribute index Creating raster pyramids Compacting and compressing geodatabases Using ArcGIS Desktop 2 • Geographic Data Management GIS data concepts What is GIS data? Underpinning all your GIS work, no matter what it is. are geographic datasets that contain the data you need to build databases, make maps, and perform analyses. One of the main roles of ArcGIS Desktop is to help you organize and manage this geographic data efficiently. First, though, it's useful to review some of the basics of GIS data. While simila in some respects to data created and stored in a database program or graphics software, GISJ data has some unique characteristics. GIS data is a digital representation—or model—of features or phenomena that occur on or J near the earth's surface. Many types of geographic features and phenomena can be model© in ArcGIS and stored as GIS data, including: • A physical object—either natural or man-made—such as a stream, or a light pole. Some objects are stationary while others are mobile, such as a delivery truck or an animal with a radio transmitter. • A defined object that isn't necessarily visible on the ground, but that can be displayed on a map. Areas defined by boundaries, such as a county boundary, are a prime example. Many boundaries are legally defined, such as parcel or congressional district boundaries, while some are formed by physical features, such as the boundary of a watershed. • An event that occurs for some relatively short period of time, such as a burglary, or an eanhquake. While the event itself is ephemeral, the location—and date and time—of the occurrence can be captured and stored. • A locator, such as a street address, or a milepost on a highway. The locator doesn't represent a physical object—simply a location that is important or useful to identify. Locators are often used to fix the location of events or mobile objects—for example, a street address is often used to identify the location of a burglary or to identify the location of customers or students (people move around, but in GIS their location is usually fixed to their home address). • A spatial network representing linkages between objects or events. Often the network I is defined on top of other geographic objects, such as a bus route which is a geographic ] feature defined from a set of streets and stops, themselves geographic features. • A phenomenon that can be measured at any given location, such as elevation above seal level, soil moisture in the ground, or the concentration of ozone in the air. What these geographic entities all have in common—from a GIS standpoint—is that they have a location that can be captured and stored, and they have properties, termed attributes in ArcGIS. The attributes might be descriptions—such as the zoning code of a parcel or the name of a stream, or they might be measurements—such as the population of a county or the magnitude of an earthquake. Linking the location of the object or event with its attributes makes it possible to create highly customized maps, to perform spatial queries, and to perform analyses that take into account the spatial relationships between objects. How do you There are a number of models for representing this variety of geographic entities, represent feature however two in particular are the most common. One represents geographic entities as geography jn a geometric shapes (feature classes); the other represents them as cell values (rasters). GIS? Typical representations of feature classes are points (such as wells), lines (such as roads), and polygons (such as census tracts). Feature classes are stored as coordinate pairs that reference locations on the earth's surface. A well, for example, might be represented as a point in a features class, with coordinates as 119 degrees west longitude and 34 degrees north latitude. A line or polygon can be represented as a series of coordinate pairs that can be connected to draw the feature. This approach views features as discrete objects on the earth's surface, and the representation is referred to as vector data. Points Lines Polygons • \--- Building location points, street centertines, and park boundary polygons are examples of feature classes. In contrast, rasters represent geographic features by dividing the world into discrete square or rectangular cells laid out in a grid. Each cell describes the phenomenon being observed. For example, the cell values in a vegetation raster represent the dominant vegetation type in each particular cell. A raster of vegetation types. Cell values can also be any measured or calculated value, such as elevation, slope, rainfall, vegetation type, or temperature. The raster data structure is commonly used for continuous categorical data (such as land cover), digital elevation models, and photo and satellite images. 64 65 Using ArcGIS Desktop 2 • Geographic Data Management While most geographic features can be represented using either of these approaches, using | one or the other is often more appropriate. For example, linear features, such as roads, are often represented using feature classes. Phenomena that occur everywhere and are measured on a continuous numeric scale—such as elevation or air quality—are usually represented as rasters. Quite often you'll work with both types of data simultaneously when creating a map or when performing analysis. ArcGIS includes tools that allow you t convert data between features classes and raster data, if necessary. This map display was created by drawing feature classes of cities, country boundaries, nvers. and waterbodies on top of a raster dataset of shaded relief. Features of a similar type within a designated area are stored in a single dataset. Datasets are homogeneous collections of geographic elements. Roads in a town would be stored in one dataset. landuse zones in another, census tract boundaries in a third, buildings in a fourth, and so on. The various datasets are often thought of—and portrayed—as layers of information for that place. During mapping and 3D visualization, datasets are symbolized, labeled, and displayed as map layers. This map display includes four datasets: a polygon dataset of lakes, line datasets of roads and streams, and a raster dataset of elevation. In geoprocessing, operators are applied to datasets to create new datasets—for example, to create a dataset of 30 meter buffer polygons around road centerlines. You apply geoprocessing operators to datasets to create derived datasets. Datasets are also the most common way of sharing data among GIS users. vj cities Feature Class Thu 9/23.2004 3:54 PM *} CitiesAnno Feature Class Thu 9/23/2004 11:06 AM id Roads Feature Class Mon 10,4/2004 10:55 AM »1 RoadsAnno Feature Class Thu 9/30/2004 8:58 AM 3t ParkBoundanes Feature Class Tue 9/28/2004 8:56 AM 21 States Feature Class Thu 9/23/2004 3:54 PM ±i Streams Feature Class Thu 9/23/2004 11:06 AM ■ utahRehef Raster Dataset Mon 10/4/2004 10:55 AM jg lSOmnaluralColor Raster Dataset Thu 9/30.2004 8:58 AM Datasets can be listed in ArcCatatog, and can be copied and distributed to other GtS users. 66 Each dataset represents a type of information for a place. 67 Using ArcGIS Desktop 2 • Geographic Data Management You also work with the individual data elements contained in each dataset—the individual parcels, wells, or buildings—and their associated attributes. For example, you can list the descriptive attributes and properties of an individual building by pointing at it on a map. Text labels can be used to annotate selected buildings. 0» W ^> tout va— t»h D <* B« f ■ . * ** ■'■ 3 B B|Bi 1 3 ■ - a - -3prn . , u a- *- j- When yot/ identify a building by pointing at % you 're working with the individual data elements in a dataset. During editing, you edit the geometric shapes of individual parcels—for example, dragging a comer to expand the boundary of a park. Spatial selection allows you to graphically select a group of features on the map—for example, the parcels that are within a quarter mite of a freeway. How do you A key concept of GIS data is that geographic datasets represent a location on or near the reference the Earth's surface. This sets GIS data apart from graphics software where objects are simply location of a stored in page units. Because the data is tied to an actual location on the surface of the dataset on the earth, you can't just create it from scratch, as you would when creating a drawing on a Earth's surface? blank page in a graphics program. (While you could draw a map on a blank page, the length or shape of features, and the distances between them, would likely not be accurate.) Datasets are stored using coordinates that correspond to positions on the Earth's surface. The coordinates should accurately represent these positions to ensure that the feature shapes and their relationships to other features reflect actual conditions on the ground. Describing the correct location of features requires a framework for denning real-world locations. This process is called georeferencing. Georeferencing is accomplished by specifying a coordinate system for the dataset. Georeferencing allows you to display on a single map various datasets—from different sources—and have them register correctly, or to combine datasets representing information about the same location to derive new data and information. If datasets were only in page units, two datasets representing the same location likely wouldn't register, depending on where they happened to appear on the page. Once georeferenced, the datasets refer to the same location on the ground, and register correctly. Each GIS dataset has a set of properties that define the specific details about its coordinate system. Once specified, the coordinate system definition is maintained with the dataset. One coordinate system for describing the position of geographic locations on the Earth's surface uses spherical measures of latitude and longitude. Latitude and longitude are measures of the angles (in degrees) from the center of the Earth to a point on the Earth's surface. This reference system is often referred to as a geographic coordinate system. You work with individual data elements when you edit features, in t park boundary. 68 69 Using ArcGIS Desktop Although longitude and latitude can locate exact positions on the surface of the globe this coordinate system doesn't allow you to measure distances or areas accurately or d.splay the data easily on a flat computer screen or map. 2 • Geographic Data Management Typical units of measure in projected coordinate systems are feet or meters. So. in fact, the coordinate values are often six or seven digits—especially since the origin of the coordinate system may be far from your study area. Each feature's coordinates are stored in these geographic units: points as x.y pairs: lines as a series of x.y pairs that define the shape of the line: the same for polygons. For raster datasets. the coordinates of the origin of the grid (usually the upper left or lower left corner) are stored, along with the cell size. Thus the extent of the raster and the geographic location of each value for individual cells can be calculated. The CIS displays-on a Hat computer screen or map-geographic features that occur on the surface of the spherical Earth. To appear correctly on a screen or map page, the features have to be transformed to a flat plane. Projected coordinate systems include this transformation and specify the origin and units of the coordinates (feet or meters, usually). Projection Plane This much earth surface has to fit onto this much map surface. Projected coordinate systems use two axes: one horizontal (x), representing east-west, and one vertical (y). representing north-south (Cartesian coordinates). The point at which the 1 axes intersect is called the origin. Locations of geographic objects are defined relative to the origin, using the notation (x.y), where x refers to the distance along the horizontal axis, and y refers to the distance along the vertical axis. The ongin is defined as (0,0). (x=2. y=1) — (0,0) These buildings (represented as points) are labeled with their x.y coordinate values. The distance between them (about 82 feet) can be calculated in the GtS by storing the geographic coordinate values instead of the page units Projected coordinates can be defined for both 2D (x.y) and 3D (x.y.z) datasets, where x.y measurements represent the location on the Earth's surface and z would represent height above or below a point of reference such as mean sea level. Unlike a geographic coordinate system (latitude-longitude), a projected coordinate system has constant lengths, angles, and areas across the two dimensions. However, all map projections representing the Earth's surface as a flat map. create distortions in some aspect of distance, area, shape, or direction. Many map projections are designed for specific purposes. One map projection might be used for preserving shape while another might be used for preserving the area (conformal versus equal area). In any case, the distortions are primarily an issue if your study area covers a large part of the globe (a country or continent), or the entire globe itself. If your study area is a county or city, these effects arc small. Many standard coordinate systems are established for the globe or for various regions—the UTM (Universal Transverse Mercator) system, for example, has a defined coordinate system for each 6-degree swath of longitude around the globe UTM is used worldwide; in the United States, the State Plane system is another commonly used coordinate system. Other countries and regions often have their own local systems that use a local set of geographic controls. 71 70 Using ArcGIS Desktop 2 • Geographic Data Management A coordinate system specifies a datum, in addition to a map projection. A datum is a mathematical representation of the shape of the Earth's surface. A datum is defined by a spheroid, which approximates the shape of the Earth and the spheroid's position relative to the center of the Earth. A local datum aligns its spheroid to closely fit the Earth's surface in a particular area; its origin point is located on the surface of the Earth. The coordinates of the origin point are fixed, and all other points are calculated from this control point. More than one coordinate system can become a standard for data from a specific region, and other coordinate systems may also be used. So, you may face the prospect of dealing with various datasets for the same location but that are in different coordinate systems. By recording and storing the coordinate system properties for each dataset (the map projection, datum, spheroid, and geographic units), ArcGIS can automatically transform the locations of GIS datasets on the fly into any appropriate coordinate system (the coordinate system of the dataset stored on disk is not changed). It's then possible to map and combine information from multiple datasets regardless of their coordinate system Alternatively, you can transform a dataset to create a new dataset in the specified coordinate system, using tools in Arc Toolbox. You can see a dataset's coordinate system by viewing its metadata in ArcCatalog or ArcMap, or by viewing its properties in ArcCatalog. See 'Defining coordiniate systems and projecting datasets' in Chapter 3 for more on assigning coordinate systems. «. am »f x . «a • □ w Roads within the park O.OMM 1..... Nh WHwifi 0.000000 Metadata tor a dataset includes a description of the dataset's coordinate system. How do you represent feature attributes in a GIS? In ArcGIS, attributes for feature classes are stored and managed in tables, which are based on a series of relational data concepts. These include: • Tables contain rows. • All rows in a table have the same columns. • Each column has a type, such as integer, decimal number, character, date, and so on. • Relationships are used to associate rows from one table with rows in another table. This is based on a common column in each table. • A series of relational functions and operators, SQL (structured query language), is available to operate on the tables and their data elements. Tables and relationships play a key role in ArcGIS. just as they do in traditional database applications. In ArcGIS, tables have an added dimension: each row in a table represents— and is linked to—a geographic element in the dataset. Additional tables can be linked to the geographic elements by a common field. For example, information on parcel owners might be stored in a separate table—the parcel identification number (PIN) serves as a link between this table and the parcels attribute table. This would allow you to associate multiple owners with a single parcel or a single owner with multiple parcels. Feature class table Shape ID PIN Area Addr Code i 334.1525-COI 7.342 341 Cherry Cl SFR 2 334-16264)02 8.020 343 Chetry CI. UND 3 334-1626-003 10.031 345 Cherry 01 SFR 4 334-1626004 9,254 347 Cherry C: SFH • 5 334.152W05 a. 856 348 Cherry Cl. UND 6 334-16264J06 9.975 346 Cherry Cl SFB 7 334-16264M7 8.230 344 Cherry Ct SFR 8 334-1S264J08 S«4 = 342 Cherry Cl SFR Tables can be linked through a common field—in this case, the Parcel Identification Number. Related ownership table PIN Owner Acq.Date Assessed TaxStat 334-16264X11 G Hall 1995 10:20 $115,500.00 02 334-16264J02 H.L Holmes 1993 '10/06 524,375.00 01 334-1626-003 W.Rodgeiü '980'09'2J 5175.500.00 02 334-1626-004 J. Wilaamson 1974:09 2Ü S135.750.00 02 334-16264X15 P.Goodman 1966 06.06 S30.35C 90 02 334-1626-006 < Slaley 1942 10 24 S1207 50.0C' 02 334-1626-007 1 Dormandy 199601 27 5110.650.00 01 334-16264306 S. GooJey 2000/05/31 S145.750 00 02 72 73 Using ArcGIS Desktop This combination of geography and descriptive information provides the foundation for the ArcGIS information model, which is often referred to as the geo-relational model. PIN Area Addr Code Owner J. Wild am son Relat. Acq.Date .=.T4 09.-20 Assessed TaxStat 334-1626-004 9.254 347 Cherry Ct. si 35.750.00 02 Featui* class Cable Related ownership table pir 4 Area Addr Code PIN Owner Relat. Acq. Date Assessed TaxStat 334-1626-001 7.342 341 Cherry Ct SFR 334-1626-00 G.Ha.1 50 1995 10 20 $1 I5-.5O0.OO 02 334-1626-002 8.020 "343 Cherry Ct UNO 334-1626-002 H. L Holm« UK I993'I0.06 5241375 00 oi 334-1626-003 10.031 '345 Cherry Ct. SFR 3)4-1626403 W Rödgen HW 1980-09'24 SI7S.500 00 02 334-1626-004 9.254 .347 Cherry Ct 5FR 334-1626-004 J.Wil liamson HW 1974 09 20 1135.75000 02 334-1626-005' 8.656 [348 Cherry Ci UND 334-1626-005 P Goconir SO 196b 06 06 s 30.3 50 00 02 334-162"6-006' 9.975 346 Cherry Ct SFR 334 1626-006 K.Sa1ey HW '942 10 24 5120 75000 02 314-!626-0O7' 8.230 344 Cherry Cl SFR 334-1626-007 j Dormandy UK I996V01I77 SI 10 65000 01 3>4-lb26-0OS' 8.645 342 Cherry Ct. SFR 3 34.1626-008 S. Goo\ey HW 2000/05/3 1 SI 45.750.00 02 77ie GIS information model includes both geographic and tabular data, and is often referred to as the geo-relational model. The geo-relational model enables key GIS tasks, such as using attribute values to label and symbolize features. Because the tabular information is linked to the geographic objects (which in turn have a geographic location), it also allows you to perform spatial queries and | analyses. You can, for example: • Point at a feature on the map and display its attributes. • Select a feature in a table and see it highlighted on the map. • Select a subset of features that have certain attribute values—that is, that meet some criteria you specify. • Use statistics to find geographic clusters of features having similar values. In the raster data model, tables function in a different way. If the raster dataset represents categorical information, such as the soil type in each cell, each row in the table represents a category rather than an individual cell. The table stores the number of cells in each category. You can also store additional attributes for each category—a soil name, crop classification, and so on. If the raster dataset represents continuous measurements, such as elevation or soil moisture, each cell potentially has a unique value, so only that value is stored with the raster, and a table is unnecessary. 2 • Geographic Data Management An overview of geographic data management ArcGIS provides a great deal of flexibility in the types of data you can view and analyze—data stored using different data models (vector, raster. TINs. and so on), data in different file formats (feature classes, shapefiles. or coverages), datasets covering different geographic areas, datasets from various sources and in different coordinate systems, and so on. ArcGIS Desktop also lets you work with or import a wide variety of other data types, including images (.bmp. .jpg. and so on). CAD files, other geographic data formats (such as DLG or TIGER") and tables (in text format or spreadsheet formats such as Excel). To be able to efficiently find and use all this data, you'll need to organize it. The main mechanism for organizing your geographic data in ArcGIS is to define a workspace. A workspace—by definition—is any folder containing your GIS data. Workspaces also contain other files and documents you collect and create in the course of your work. Workspaces are viewed and managed in ArcCatalog. Here is a workspace named Yellowstone, containing several datasets and associated files. These are the most common types of datasets and files you'll work with. A gecdatabase A single geodatabase feature class - -Jjl lakes 3 rivers id streams £2 toundary.shp dem30 elevation.lyr <*Q etevation.sxd — _hfehade. img Q hyckokJOjy.ryr §J mask.shp Si study _area.shp aj än_s*urjy IE ver/Tpedbf yelwrtone.rrLxd A geodatabase "feature dataset" containing : three feature classes An ArcMap document (.mxd file) A shapefile datasot 11 JL.^1 \ IIS- lilt A table stored as a dbfeie 74 75 Using ArcGIS Desktop Organizing and managing workspaces in ArcCatalog A geodatabase is both a format for storing datasets and a way of organizing related datasets. Geodatabases are the primary way geographic data is stored in ArcGIS—they are discussed in more detail later in this section. ESRI shapefiles and coverages were used in earlier versions of ESRI software (ArcView CIS 3 and Arclnfo Workstation, respectively). Much geographic data is still available in these formats, and the datasets are still widely used in ArcGIS Desktop. ArcMap documents, ArcScene™ documents, and layer files are created as you build maps and 3D views. You'll read more about them in Chapter 4. 'Mapping and Visualization', and Chapter 5, 'Geographic Analysis". ArcCatalog is the primary application for organizing and managing workspaces and datasets. If you're collecting existing data, you set up a structure and copy the datasets into it (or import them). If you're creating new data (by digitizing, for example), you first create the individual datasets, and then create the features within them (see Chapter 3, 'Data Compilation and Editing", for more on creating features by editing). Setting up a workspace structure When possible, you'll want to define the structure for your data organization before starting a map or a GIS project. In the case of building a large, multiuser database this is essential. Your workspaces may consist of a single file folder containing many datasets and other related documents that are organized around themes or projects. For example, if you have a statewide GIS, you might have your data organized by county. Many users organize their projects by theme, such as workspaces for roads, water, parcels, administrative boundaries, and so forth. In other situations, you may want to organize workspaces around a project such as a road development project or new power plant project. You can also organize workspaces within workspaces. For example, you may have a project workspace "New power plant", and within that workspace you may have subfolders organized for each dataset or for each project task, such as"New dam." "New road." or "New transmission lines". 2 • Geographic Data Management * _J tarn« Zart* This statewide workspace contains a folder for each county: The content of the county workspaces is consistent. This simple project workspace organizes datasets in folders, by the type of data. This workspace for a major project contains subworkspaces for each element of the project. The wori« ■ S jCJ TracingCenmdtn j Double-click an option under Database Connections to add a connection to an OLE database or data stored in an RDBMS. Double-click an option under GIS Servers to add a connection to an ArcGIS Server, an ArclMS Server, a web mapping server (WMS), or a server on the Geography Network. A sample geodatabase data model document showing the various datasets and associated attributes, as well as the links between tables. 84 85 Using ArcGIS Desktop Some connections may be established once, for databases you access on an ongoing basis; others may be connections you set up on an as-needed basis to access data for a particular map. If the connection is not currently valid (the data has moved or the server is unavailable), a small red x will appear next to the connections name. You can have more than one connection to the same data source—for example, a connection to a CD at the highest level and additional connections to folders and subfolders on the CD. • ■«! . teures* - jw»r«pi * _J Rotöl PTW3 . fit* 4 icweb Servern • Ji Ccerdn*» Srtttms - JJOati 3jAddD*t«Us«S*Tvv - 5 *rrioi>i»Bd MO.C€F*J.T) 3 *dd *VcS5 5«W 43 Add WW Sow - J r^Cg^r^-Drti4»^IVMt^t^tyiI fed* AJdr mi Locators Ybu can sef up multiple connections to the same source—/n (his case, data stored on a CD Once you're done accessing the data or no longer need the connection, you can disconnect by right-clicking the connection and selecting Disconnect Folder. Right-click the connection and select Disconnect Folder 4* C.I The established connections appear in the Catalog tree ■ ■ o J fucabm* Corrected "iOSStw*™ Database and server connections Storing geographic data in a relational database management system lets many people within an organization access the same set of data. Storing data on an ArcGIS or ArclMS" server lets people both inside and outside an organization access the data. These connections are often established by a GIS or database system administrator. One special server connection is to the Geography NetworkSM, a clearinghouse for GIS data supplied by users worldwide. When you connect to the Geography Network you get a list of currently available images and feature data you can preview, and add to your map. Geography Network Services lets you access images and features and services 86 2 • Geographic Data Management Previewing a feature's geography or attributes ^3nd PreV'eW ^ The" ^ - - » P^iew the When previewing geography, you can point to a feature with the Identify tool to list that features attributes. Identify .--- Milt t»77M Using ArcGIS Desktop You can preview an attribute table associated with a feature class or another data table in a compatible format—for example, dbf You can explore the table to make sure, for example, that it's the most current version. ft. a 4 «r x I-1 b* 4 » O VT « * • » * [ i r Right-- », Hr.*«» — The search X bto ,». b to ft. a* « P X J. Rightelick a shortcut to access the item's Properties dialog box. You can delete or rename searches the same way you would delete or rename any other item in ArcCatalog. To see the criteria for a search, select it and select the metadata tab. To rerun a search, or to modify the criteria and then rerun it, right-click the search and click Properties—that opens the Search dialog box. a, &m «i f x ««•oft 1 My Search Thti wMrcn toofci tor c cnitm Oata loriltd wtran tM fofc-i-fl a™« MfWntMK -12S .V700VS -1SS.TV4S2? ll WW* Rightb& rev* r~a~i «- i_i 96 97 Using ArcGIS Desktop Stylesheets with filenames that begin with "FGDC" present metadata stored in the XML elements defined by the Federal Geographic Data Committee (FGDC) Content Standard for Digital Geospatial Metadata. f> 4» ifeP > boundary of Yellowstone National Park FGDC and ESRI Metadata: *.|K iB( A « • □: V «e • o * um» bimTaimTalVfjV^ / *■ • ■--—-.1. -i-" it-. ------------ - * * «et-» - *'-st"w^11 „,,,, • *" Boundary of Yellowstone National 3 Park Me La data: . 'W*-—„ tew. ---3 7Vre Fc3DC siy/esfteef presents a summary of the dataset at the top of the metadata. The FGDC Classic stylesheet provides a set of links to quickly jump , to the pertinent section of the metadata. « « • o * ; ■•^jLjur** -»-Wf ■Tantum * « • o * W-< |^kn?Hl^ .» f " i-fji »I ---- t —; If %C* ■ 4 ■ • f torn lent (J nation i ll(HtM * " -#: - -; -—"■»— ».«—.«. * Description ttMM <■..... M i-.joe'« T(Tii-:iri oat h 1 M ' - ' ~i 1 tan. Period ol Content Content Sudji T/ie FGDC FAQ stylesheet presents a set of frequently asked questions so you can jump right to the information you need. It's useful for datasets accessed by many users. The FGDC Geography Network stylesheet is used at the Geography Network data clearinghouse. It uses a citation format so users can quickly see if the dataset wilt be useful for their purposes. Stylesheets beginning with ISO present metadata stored in the XML elements defined by the ISO standard 19115. Geographic Information-Metadata. In addition to the existing stylesheets, you can customize the metadata stylesheets provided by ESRI and add your own XSLT stylesheets to ArcCatalog. When you print a copy of a dataset's metadata in ArcCatalog, the metadata will print exactly as you see it in the Metadata tab. If you're using the FGDC ESRI stylesheet, click the appropriate tab on the metadata page and expand the appropriate headings so that you can see the information you want to print. 2 • Geographic Data Management With the Metadata tab selected, choose Print Metadata from the File menu. Editing metadata documentation Metadata consists of properties and documentation. Properties, such as the extent of a shapefile's features, are derived by ArcCatalog and added to the metadata. Documentation is descriptive information you enter using a metadata editor—for example, legal information about using the resource. Two metadata editors are provided with ArcCatalog. One lets you create complete documentation following the FGDC's Content Standard for Digital Geospatial Metadata. The other editor lets you document your data following the ISO standard 19115, Geographic Information—Metadata: it supports only the core metadata elements as defined by that standard. Use the Metadata tab on the Options dialog box to select the editor you want to use. Select Options on the Tools menu to open the dialog box. then select the Metadata tab. Use the drop-down arrow in the bottom box to select the metadata editor to use. 98 Select the editor 99 Using ArcGIS Desktop The editor selected in the Options dialog box will appear when you click the Edit Metadata button on the Metadata toolbar. * < • O * C/i'ciV fhe Hcfii* Metadata button on the Metadata toolbar to display the current metadata editor. The FGDC editor is divided into major sections, listed at the top of the dialog box. Click a section heading to display the tabs for that topic. The ISO editor is presented as a wizard. You can step through the panels using the Next button, or click a topic on the list to jump to that panel. 2' Geographic Data Management Importing and exporting metadata If you have metadata that was created outside of ArcCatalog, you can import it if it's stored in one of the input formats supported by the FGDC's metadata parser utility. You might export metadata to publish it on a data clearinghouse website. Exporting to HTML format creates a file that represents the selected item's metadata exactly as you see it in the Metadata tab. Exporting to XML format creates an exact copy of the item's metadata in a new XML file: this lets you work with metadata for geodatabase items outside ArcCatalog. Use the buttons on the Metadata toolbar to import a dstasefs metadata from (or export It to) one of several standard formats. Before you start writing documentation, you need to decide which metadata standard you're going to follow. If you don't have any metadata yet and don't need to create metadata according to a specific standard, the ISO editor might be right for you. If you have a requirement to create FGDC metadata, if you already have FGDC metadata, or if you want to create detailed metadata, the FGDC editor would be a good choice. Once you've decided which metadata standard you're going to follow, use the editor that corresponds to that standard. Whichever editor you use, the information you enter will still appear in any of the style sheets. A metadata document in ArcCatalog can contain both FGDC and ISO content. These two standards can exist in parallel in the same metadata document because they each use a completely different set of XML tags to store their information. Therefore, if you provide a title using the FGDC editor and you later switch to the ISO editor, the information you previously added won't appear in the editor. 100 101 Using ArcGIS Desktop Select Schema Only, and type the name of the XML file (or browse to locate it). This same wizard is used to load an entire exported geodatabase, including the data. After renaming the new geodatabase. right-click it, click Import, and dick XML Workspace Document to open the wizard. The wizard shows you all the empty geodatabase components that will be created. Select and type over the Target Name for a component to rename it (ff necessary), then click Finish. The result is a new schema with no data but with all the feature datasets. feature classes, tables, topologies, relationships, geometric networks, domains, subtypes, and field properties from the source geodatabase. You can then review the schema and modify it to suit your needs, deleting some items and adding or changing others. ............... «. 4 m » e w „ , , j—--j * ~"—~z m — — ..- ^--i '--1 1 tH - ttWI'ii f..in tl a When you import the schema, the various datasets are defined and created as empty containers. If you preview the geography for a feature class, tor example, you'll see that the preview panel Is blank—there are no features to preview. If you preview the attribute table for the feature class, you'll see that the columns have been created but there are no records in the table. Once your schema is ready, import the existing data into the defined geodatabase datasets. 2 • Geographic Data Management The first panel of the Simple Data Loader wizard explains what it does. To load data into one of the empty containers. righKlick it. click Load, and click Load Data. That opens the Simple Data Loader wizard. 104 Browse to the dataset containing the data to loadr then Add it to the li$t (you can toad multiple datasets of the same type at one time). This panel shows the geodatabase and feature class the data will be loaded into- Here s where you specify which attributes correspond to which fields in the table (if the field names arent the same). The default is to load ad the features, but you can load a subset of features—select Load only the features that satisfy a query, then use the Query Builder button to specify the selection criteria. The final panel shows you a summary of the data that will be loaded. Click Back to make changes, or click Finish to load the data. 105 Using ArcGIS Desktop : g a • «ant>< it— ''issss -NM ■ n_ |- ... J 2 • Geographic Data Management Once the data is loaded, the feature class now contains features. The feature geography can be previewed in ArcCatalog, and the features can be added to a map in ArcMap. The feature attribute table contains the attribute values for each feature. Another way to copy the schema of a geodatabase is to use the Extract Data wizard in ArcMap. It allows you to modify the spatial reference of the new schema you create and to set a map extent for the data you want to copy into your geodatabase. This is useful because the spatial reference requirements of your new geodatabase will probably be different from those of the source geodatabase. Creating feature classes and tables Feature classes and tables are two of the basic datasets in a geodatabase. Feature classes store geographic features of the same type and their associated attributes—for example, you'd create one feature class for roads, another for streams, and a third for parcels. Standalone tables store additional descriptive information that can be related to the geographic features. When building a geodatabase structure (or schema) from a design, after creating the geodatabase you'll create and define the empty feature classes and tables. You first create the empty feature class or table. You then define any additional fields containing descriptive data. Later you'll add data to the datasets by importing or editing. Creating a feature class Feature classes contain both the geometric shapes of each feature as well as their descriptive attributes. tí. * • n w *; « • o To create a feature class, right-click the geodatabase in the Catalog tree, point to New, and click Feature Class. The Extract Data Wizard is available from the Distributed Geodatabase toolbar in ArcMap. To open the toolbar, click the View menu and point to toolbars. Enter a name for the table or feature class, and an optional alias. Then define the type of feature. Define the coordinate system for the feature class. Select a predefined coordinate system, import one from an existing dataset, or define a new one. ArcGIS uses the tolerance to evaluate if features connect or overíap. X.Y coordinates within the tolerance distance are considered to be coincident. The default tolerance is an effective choice in mast cases. Configuration keywords are used to handle special data storage needs. For example, if your database will be larger than 1GB or if you need to store attributes containing Chinese or Japanese characters, you'd specify the appropriate keyword (these are specific to each DBMS). Otherwise, choosing Default is a suitable option. New feature classes have a default ObjectlD field and a Shape field that specifies the type of feature (point, line, or polygon). This dialog box is where you specify additional fields, by typing the name and data type in an empty row. 106 107 Using ArcGIS Desktop Feature classes store features in vector format. Vector data is often used to represent features that have a discrete location in space—such as wells, streets, rivers, states borders, and parcel boundaries—as opposed to being continuous across space, such as elevation or rainfall, often represented using rasters (see 'Managing raster datasets in a geodatabase" in this chapter). The most common vector types arc points, lines, polygons. Annotation, which is used to label features, is also stored as feature classes (see 'Creating and editing annotation' in Chapter 3). Multipoints are often used to manage arrays of very large point collections, such as LiDAR data. Multipatches are a 3D geometry used to represent the outer surface of buildings or other objects having volume. You can also specify whether the feature class includes Z or M values. Z values are most commonly used to represent elevations, but they can represent other surface measures. M values are used to interpolate distances along linear features, such as along roads, streams, or pipelines. A common example is a highway milepost measurement system. The coordinate system for each dataset is for georeferencing. It can be imported from an existing dataset. or you can create a custom coordinate system by defining its properties (you'll likely either import a coordinate system or select a predefined one). Most organizations use one coordinate system—appropriate for their geographic location—for all their data. Feature classes can also be created within a feature dataset in the geodatabase (see the next section. Ensuring spatial data integrity'). In this case, the spatial reference will be defined for the feature dataset. so you don't need to specify it. 2 • Geographic Data Management Creating a standalone table The process for creating a standalone table containing only tabular data is similar to class containing geographic features. The main difference'is that you don't specify a feature type. |-5~1 Use the Imparl option to assign the feature class the coordinate system of an existing dataset the process for creating a feature coordinate system, tolerance, or Enter a name and alias tor the table. To create a table, right-click the geodatabase in the Catalog tree, point to New. and click Table -3 —IJ - I ^_l Z±2 <~* I Use the New option to define the parameters of a geographic or projected coordinate system. As when creating a feature class, ' --TT» »SKI;™ ^K3UH jtfjU 4\ To create a feature class within a feature dataset. right-click the feature dataset, point to New, and click Feature Class As you develop the geodatabase, you may add topologies, relationship classes, and specialized datasets to the feature dataset. Creating a geodatabase topology Besides referencing the same location on the Earth's surface, datasets for the same place often have spatial relationships with each other. These are relationships you can see when looking at a map and are often intuitively obvious, but they must be made explicit in the GIS. For example, streets must connect at intersections; parcel boundaries cannot overlap; parcels nest within block boundaries; and so on. A geodatabase topology is a set of rules that specify how points, lines, and polygons share geometry. The rules can apply to features within a single feature class—for example, one topology rule would ensure that adjacent features, such as two counties, will share a common edge, so county boundaries don't overlap. The rules can also apply to features in different feature classes. For example, county boundaries (one feature class) must completely nest within states (another feature class), and share edges along state boundaries. A topology is created within a feature dataset, and applies to one or more feature classes in the dataset (so if you want to create a topology in your geodatabase. you must first create a feature dataset and add the pertinent feature classes to it). Only feature classes in the same dataset can participate in a topology, but not all the feature classes in a dataset are required to participate in the topology. And a feature class can only participate in one topology at a time. When you validate a topology. ArcGIS checks the rules you've established. To ensure the rules are not broken. ArcGIS will, if necessary, snap feature vertices together to make them coincident. For example, if two street centerlines are supposed to connect but don't quite meet. ArcGIS will snap the end points of the lines together. Specify a cluster tolerance to control how far features are allowed to move during snapping (the default cluster tolerance is the minimum possible). The cluster tolerance should be small, so only close vertices are snapped together. A typical cluster tolerance is at least an order of magnitude smaller than the accuracy of your data. For example, if your features are accurate to 2 meters, your cluster tolerance should be no more than 0.2 meters. You'll want the less reliable features to snap to the more reliable ones. Ranks are used to implement this. Vertices of lower-ranking features within the cluster tolerance will be snapped to nearby vertices of higher-ranking features. 114 115 Using ArcGIS Desktop 2 • Geographic Data Management To create a topology, right-click the feature dataset, point to New. and click Topology. That opens the New Topology wizard. Specify the number of ranks, and use the drop-down menus in thB Ranks column to assign each feature class a rank. Features having a lower rank will snap to those having a higher one- Click Add Rule to add rules—use the dropdown menus on the Add Rule dialog box to construct the rules. Enter a name for the topology, and specify a cluster tolerance (or accept the default value). Add all the rules you need to the list. You can save the rule list to use with topologies in other feature datasets and geodatabases. Select the feature classes that will participate in this topology—you can have more than one topology in a feature dataset. but each feature class can participate in only one topology. The final panel displays a summary of your topology definition. Click Back to make changes, or Finish to create the topology. After the topology is created (and before it's added to the feature dataset) you're prompted to validate it—click Yes. Validation checks to make sure the rules are met. During validation ArcGIS may actually move features (by snapping, for example) to ensure the rules are adhered to—but only within the cluster tolerance. If a feature would have to be moved farther than allowed by the tolerance, it is not moved, and an error is recorded. Once validated, the topology is added to ArcCatalog in the feature dataset Validation records errors—that is, instances of rule violations. You can get a list of any errors (or confirm that there aren't any) by accessing the topology's Properties dialog box (see below). You can fix errors by editing them in ArcMap—the Topology toolbar has tools to do this (see Chapter 3, 'Data Compilation and Editing'). Managing a topology You can view and manage topologies in geodatabases through ArcCatalog—right-click a topology in the Catalog tree and click Properties. New feature classes can be added to a topology at any time, as can new rules. When the rules or other properties of a topology are changed, the topology will need to be validated again. You can also view a summary of the number of errors in a topology from the Topology Properties dialog box. The summary tells you how many errors exist for each of the topology rules. Deleting a topology does not delete or modify the participating feature classes themselves; it merely removes the rules governing their spatial relationships. Copying a topology also copies the feature classes that participate in the topology. To rename or delete a feature class that participates in a topology, you must first remove the feature class from the topology. Either that, or delete the topology. 116 117 Using ArcGIS Desktop 2 • Geographic Data Management Righl. Once created, subtypes are used in several places in ArcGIS Desktop. When you view the feature class table or standalone table in ArcCatalog or ArcMap, the subtype name appears in the field, rather than the original value the subtype is based on The original codes for the Development Code Held. After the subtypes are created, the subtype descriptions are displayed. 2 • Geographic Data Management When you preview the feature class in ArcCatalog, the features are symbolized by subtype-normally they're all drawn using a single symbol. Similarly, when you add the feature class to a map in ArcMap. the features are automatically svmbolized by subtype. f■■ - -■ ■ - ■ ■ ~ When you preview a feature class that has subtypes, the features are displayed using a different color for each subtype. When you edit attributes in ArcMap, the subtype names are displayed in the field. Any default values or domains you ve defined are act.ve. If you change the subtype, any default values are automatically applied and any domains automatically become available. 3 ana! When editing the attributes of a feature in ArcMap. the subtype descriptions are listed. If you change a feature's subtype, any default values or domains associated with the new subtype are immediately applied. 122 123 Using ArcGIS Desktop 2 • Geographic Data Management Building relationships between features and tables A feature class stores the geometry of geographic features and their attributes. In many cases, you'll be able to store all the descriptive information for the features in the feature class. There may be cases, though where it's more efficient to store information about the features in a separate table, and relate the records in this table to the features in the feature class, using a common field. One way to do this in ArcGIS Desktop is to create a relationship class in your geodatabase. The relationship class defines the relationship between the feature class and the related table, or between two standalone , tables. For example, you may want to store information about the owner for each parcel in a feature class (the owner's mailing address, phone numbers, tax ID, and so on). One person might own several parcels: it would be redundant to store all that information in the feature class for every parcel that the person owns. Conversely, a parcel might be owned by several people: it would be difficult to store their names (let alone their other information) in the record for that parcel—you'd have to have multiple fields (ownerl. owner2, owner3, and so on). To solve this dilemma, you'd create a relationship class between the feature class of parcels and a table of owners. Each parcel and each owner is listed once, in their respective tables. A common field in the two tables acts as a key to relate records—in this example, you'd likely use the parcel ID. When you point at a parcel on a map in ArcMap to see who owns it, ArcMap uses the relationship class to select and display the related owner records for that parcel. When you select an owner in the owner table. ArcMap will display all the parcels owned by that person. Relationship classes are often used to maintain descriptions of category codes. For example, each parcel may have a landuse code, with the detailed description of the code stored in a related table having one record for each code. If you need to change or update a particular code description, you just edit the record in the related table. Relationship classes are also useful if related tables are maintained and updated separately, or if the attributes you need in a feature class are already stored in another feature class. For example, you may have a feature class of counties, with the health statistics for each county stored in a separate table that is updated monthly. Rather than continuously updating the attributes in the counties feature class, you simply create a relationship class to relate the counties to the health statistics table Attribute relationships can also be created using joins and relates in ArcMap (see 'Joining tables" in Chapter 5). These relationships are stored only with the map in which they are created. Relationships created in the geodatabase are available for any map and throughout ArcGIS. Setting up a relationship class in the geodatabase has several other advantages. A relationship class can be set up so when you modify a feature, related features update automatically. This can involve moving or deleting related features, or updating an attribute. For example, you could set up a relationship such that whenever you move a utility pole, attached lines and transformers move with it. By setting rules, a relationship class can restrict the type of relations that are valid. For example, you can specify that a pole may support I a maximum of three transformers. Creating a relationship class You can create a relationship class at the geodatabase level or the feature dataset level—either way, all the feature classes and tables in the entire geodatabase are available for the relationship; the only difference is where the relationship class will reside. Right-click a geodatabase or feature dataset, point to New. and click Relationship Class. The wizard will prompt you for a name for the relationship class and the participating feature classes or tables, as well as other properties. You can create a relationship class between a feature class and a standalone table, two feature classes, or two standalone tables in your geodatabase. Enter a name for the relationship class, and select the origin and destination feature classes-tables. In general, the destination is the feature class/table you're relating the associated table to. In this example, a table of owners is related to parcels—Owners is the origin and Parcels the destination. Specify either a simple or composite relationship. In a composite relationship, if a record in the origin is deleted, the related records in the destination are also deleted. In a simple relationship this is not the case. To create a relationship class, right-click a geodatabase or feature dataset in the Catalog tree, point to New. and click Relationship Class. The process is the same either way—the only difference is where the relationship class will be stored (under the geodatabase, or under the feature dataset). Use messages to enable automatic update of records between the feature classes/tables. You can later set up rules to specify when and how updates will occur (for example, when you move a feature you can have features in a related feature class move witli it). 124 125 Using ArcGIS Desktop 2' Geographic Data Management jjjbj Specify whether , one record in the origin relates to only one record tn ' the destination, one record can relate to more than one record in the destination; or multiple records in the origin can relate to multiple records in the destination. Specify whether the relationship class will have attributes—that is. whether each linker! pair of records has associated fields, such as the percentage of a parcel owned by a particular owner. If Yes. an intermediary table is created, and the Next button displays a dialog box in which you define the fields. Each record in the table represents a linked pair of records. 31* Lastly, specify the fields in the origin and destination feature class/table containing the common values used to relate records. These are known as keys. 126 The final panel displays a summary of the options you specified. Click Back to make changes, or Finish to create the relationship class. If you spacified that the relationship class contain attributes or you specified a many-to-many relate, or both, an intermediary table is created. In addition to the origin and destination keys, you specify the field(s) in j the intermediary table that correspond to the origin and destination keys. On the first panel of the wizard, you choose one feature class/table to be the origin and another to be the destination. An edit made to the origin will affect the destination. For example, in the landusc code example above, you'd set the code table as the origin and the parcel feature class as the destination. Deleting a parcel (a destination object) will have no effect on the code table, and deleting a landuse code (an origin object) will set the value of the code field in the matching parcel records to Null, which is as it should be, because they no longer have a matching code table record. If you set the parcels as the origin, deleting a parcel would set the value for that code to Null in the code table; all other parcels having that code would no longer have a match in the code table. When you create a relationship class, you specify whether it is simple or composite. In a simple relationship class, if you delete a record in the origin table, the value for the corresponding record in the related table is set to Null. In a composite relationship, destination objects can't exist independently of origin objects, so when the origin is deleted, the related destination objects are also deleted. You can have origin and destination objects send messages to notify one another when they are changed, allowing related objects to update appropriately. For example, updating an origin can require related destination objects to update. If updating an origin requires related destination objects to update, set the message notification direction to Forward; specify Backward for the reverse. Or. specify Both. Once you've created the relationship, you must then set up rules for the objects that receive the messages so they can respond. The type of relate—one-to-one, one-to-many, or many-to-many—is known as cardinality. The parcel/owner example earlier describes a many-to-many relate (one or more parcels can relate to one or more owners); the landuse code example is a one-to-many relate (one landuse code relates to many parcels): and the county health statistics example is a one-to-one relate (each county in the feature class has a corresponding record in the health statistics table). The common fields that relate the feature classes/tables are called keys. The key field in the origin class of a relationship is called the primary key; the key field in the destination class is called the foreign key. It contains values that match those of the primary key field in the origin class. The key fields may have different names but must be of the same data type and contain the same kind of information, such as parcel IDs. In one-to-one and one-to-many relationships, values in the primary key of the origin class directly relate to values in the foreign key of the destination class. Many-to-many relationships, on the other hand, create an intermediate table to map the associations. When the intermediate table is created, only the fields are generated for you. ArcGIS does not know which origin objects are associated with which destination objects, so you must manually create the rows. Each row-associates one origin object with one destination object. The intermediate table of a many-to-many relationship can optionally serve a second purpose—storing attributes of the relationship itself. For example, in a parcel database you may have a relationship class between parcels and owners, where owners own parcels and parcels are owned by owners. An attribute of each relationship could be the percentage of ownership. If you need to store such attributes, you can add them to the intermediate table when you create the relationship or anytime after. When you're setting up a one-to-one or one-to-many relationship, you may have the same need to store attributes of the relationship. If this is the case, you must specify this when you create the relationship so an intermediate table is created for you. Specifying the number of allowed linked records Once you've created the relationship, you can specify rules to refine the cardinality. In a relationship of parcels and buildings, for example, you might specify that each building must be associated with a parcel, or that a parcel can contain a maximum of three buildings. This prevents a user from forgetting to associate a building to a parcel or from associating too many buildings to a parcel when editing data, and ensures the integrity of the relationships between feature classes and tables. 127 Using ArcGiS Desktop In ArcCatalog. right-click an existing relationship class to display its Relationship Class Properties dialog box and click the Rules tab. If the origin or destination has subtypes, click the subtype you want to apply the rule to. If there are no subtypes, the relationship rule will apply to all features. Check the boxes for the origin and destination cardinality. Set the appropriate Min and Max cardinalities for the rule. Select the origin subtype to participate in the rule, then select the destination subtype (make sure the box is checked). Then specify the number of allowed linked records. In this one-to-many relate, one private parcel owner can be linked to anywhere from 0 to 5 non-residential properties. Set the Max first, since the Min must be less than the Max. 2 • Geographic Data Management To create a relationship class rule, right-click the _I * 1 c*^* I relationship class in the catalog tree, and click Properties, then select the Rules tab on the dialog box. After you've set up the rules, you can test them in ArcMap with the Validate Features command. Managing a relationship class Once you've created the relationship class, it appears in the Catalog tree, and you can inspect—but not change—its properties by right-clicking it and clicking Properties. You can. however, set and change relationship rules on the Rules tab. When you delete a feature class or table in ArcCatalog, if that feature class or table participates in a relationship class, the relationship class is also deleted. i vr « « • o 9. Accessing table relationships in ArcMap You can use ArcMap to explore the relationships established by the relationship class. When you identify a feature in your map. you can see the features or records related to that feature in the Identity results dialog box. 4 *?!fll ■ -r—j After identifying a feature, expand the tree associated with the feature, then click the ID of the related record to display the attributes in the related table. OEJtCTC 20-5 El£tuK* MM PWCftTY S 3166 OtatCft MMC OTT M6I PEflCEHl 0 DCEO t*I£ »• SBJCI C**IJ0 trau HSU* 1871 pl Mb 11 " J - 3 'mmr.mt.rx -t 0 >w.g««»#i».. .■ -fj. J..» - H«.nm<« -'J To import a raster, or to mosaic several rasters, without first creating an empty raster dataset in the geodatabase and defining its properties, right-click the geodatabase, point to Import, and click Raster Datasets (mosaic). Properties of the output dataset are derived from the input raster(s). 4 Oft J CjflflU I jfnWWti J VtmiUCH J 130 131 Using ArcGIS Desktop 2 • Geographic Data Management If you want to import a single raster dataset. or import several datasets at one time but continue to store them as individual datasets (rather than mosaicking them into a single dataset). choose the "Raster Datasets" option. After creating the catalog, you load raster datasets into it. ' ±1 »I ♦I — «j To import one or more rasters into a geodatabase as individual raster datasets. right-click the geodatabase, point to Import, and click Raster Datasets. t CirJdog ■ * _| Arrw. >-mC - _| »o*rfrkX Pro)«* <— r 1 elr<_arw t ■ Or.Wcr> - _| - - ■ • > '.'awerl- _4 /vcw* Servern ■ Jf( .. * v- * :-vJti TTie rasters are stored individually in the geodatabase. Creating a raster catalog A raster catalog lets you manage a group of individual rasters as a collection. The rasters could be a tiled image—such as all aerial photos for a county—that you want to maintain as separate tiles (rather than mosaicking them into a single dataset); a set of coincident rasters for a location (such as layers for soil type, elevation, rainfall, and so on); a time series for a location (such as urban versus rural landuse for each decade); or any other collection of rasters you want to keep together, such as all the output rasters from a GIS analysis project. You first create and define the raster catalog. Right-click a geodatabase, point to New. and click Raster Catalog. To create a raster catalog, hght I I 140 Specify whether you're building a network from existing feature classes, or you're building an empty network that you'll load data into later (in which case the next five panels are skipped). Select the feature classes that will participate in the network (a feature class can participate in only one network at a time). The Enabled field (set to either true or false) is added to each feature class in the network to specify whether speciffc features can participate in tracing flow over the network. The value is initially set to True—you can change this by editing the feature class later. This panel is presented when one or more of the feature classes already has an attribute field called Enabled (H may have previously participated in a network). Specify whether to use or overwrite these values. 2 * Geographic Data Management Specify whether to build complex edges. If No, line features (edges) will act as simple edges and will connect only at endpoints. If Yes. you can specify which tine feature classes will have complex edges and will connect at endpoints or where edges intersect (do this if you want to maintain certain features as single entities, even if they're intersected by other features). Accept the default to snap features, unless you've already edited all the participating features classes to ensure line ends and junctions are connected. Specify whether any of the point feature classes in the network represent sources or sinks. You'd include sources and sinks if you'll be modeling flow through the network. Assign any weights that will be used when modeling How through the network. These represent the cost of traversing an edge (or junction) in the network. You can then associate weights with fields in the appropriate feature class (by accessing the feature class properties and selecting the Weight Association tab). The values in the field are used as weights. The final panel displays a summary of the options you specified. Click Back to make changes, or Finish to create the geometric network. a-— a— Xl MM -— CSS— J3T The geometric network is added to the feature dataset. To see the list of participating feature classes and their role in the network— along with connectivity rules and weights you've assigned—right-click the geometric network and click Properties. 141 Using ArcGIS Desktop Creating an address locator for geocoding A common way of locating geographic entities is to use street addresses. This is often done for tables of customers, students, or any other entities that have an associated street address, such as crimes. The process of assigning coordinates to street addresses is called geocoding. To assist in geocoding. you add an address locator to your geodatabase. A locator is a combination of one of more feature classes containing addressable features, such as address range information for street centerlines, and a set of address styles and parameters that direct the matching process. Each locator dataset is used as the source for matching a single address or a large file of addresses in order to find address locations. See "Assigning locations using street addresses or routes' in Chapter 3 for more on geocoding. Right-click the geodatabase. point to Import, and click Address Locator. Then pick an address style from the list—styles include basic formats such as the entire address in a single field, to a wide range of standardized formats having multiple address fields. 2 • Geographic Data Management •-I 1 r=- rr Use the Address Locator dialog box to specify the parameters for address matching, such as field names, intersection separators, and matching rules. Creating a route dataset for linear referencing Some GIS applications employ a linear measurement system used to measure distances along linear features, such as along roads, stream lines, and pipelines. One common example is a highway milepost measurement system used by departments of transportation for recording pavement conditions, speed limits, accident locations, and other incidents along highways Values on the measurement system represent milepost distance from a set location such as a county line, or distance from a reference marker. Support for these types of applications is referred to as linear referencing. Linear referencing is implemented in ArcGIS | using route feature classes, which you build from linear features (such as local streets and highways) that have a common measurement system. When creating a route feature class, you must define the geometry field's type to be polyline and indicate that it is able to store measure values. You also need to add a route identifier field. This field uniquely identifies each route. There e several ways to create routes in ArcGIS. The simplest is to use the Create Routes Wizard in ArcCatalog. (You can also create a route feature class and then load data into it; use the Linear Referencing tools in ArcToolbox; or create routes interactively in ArcMap. See "Editing routes and geometric networks* in Chapter 3 for more on linear referencing and on creating routes in ArcMap.) To use the Create Routes Wizard you first need to add the tool to a toolbar in ArcCatalog. To add the Create Routes Wizard button to a toolbar, click Customize on the Tools menu. Then, on the Commands tab. select Linear Referencing in the Categories list, and drag the tool to a location on the Standard toolbar (or another open toolbar). You then select the dataset the routes will be created from, such as a roads feature class having route identifiers and milepost measures, and click the tool to open the wizard. In the Catalog tree, click the feature class you're creating routes from. Then click the Create Routes Wizard button you just added to the toolbar. The input feature class is automatically entered. From the drop-down list, select the field in the input feature class containing the route identifier for the features (this field has to exist in the input feature class—it's used to assign features to a route). Specify how the route measures wilt be derived. You can use the lengths of the features, or use an existing field (or to-from fields) in the input feature class. Specify whether to create the route as a feature class in a geodatabase, or as a shapefiJe in a folder. 142 143 Using ArcGIS Desktop 2 ■ Geographic Data Management Specify the location and name of the new route. ] mi ■ftf^iu^ CWItqBtMwMkWPil unkrib we i Mtaa Off xfte*fl min -J .r1 Vot/ can create the route using all features in the input feature class, or use the Query Builder to select a subset of features. You'd use a subset, for example, to exclude features that are not part of a route (as shown here—features with a route ID not equal to 0). or to create routes using only certain route IDs, or to create routes from another selected set (such as a particular road type—only highways, for example). Once the route has been created, you can add it to a map in ArcMap to display and query it—for example, you can point at a location on a route and get the measurement at that point. You can also assign geographic locations to events—such as accidents—that have route measurements rather than street addresses or geographic coordinates. The events can then be displayed on a map. This is a common reason for creating routes. See 'Assigning locations using street addresses or routes' in Chapter 3 for more on adding route events to a map. Routes can be used to assign geographic locations to events stored in a table {such as road accidents). The events need to have a route ID Field and a measurement field (such as a milepest number). The final panel summarizes the route parameters. Click Finish to create the route, or Beck to make changes. The route is created as a feature class in the feature dataset. As with any other feature class, you can access its properties by right-clicking it in the Catalog tree. Rightetrck the route to access its properties (some of which you can modify). r^—\ r— I ~ I 144 145 Using ArcGIS Desktop Maximizing the performance of your database As you add more and more data to your geodatabase and make changes to the data, the speed with which ArcGIS can search and display the data may sutler. And the size of your geodatabase files may grow. There are several things you can do to make sure your database can access and display your data quickly and efficiently. Creating indexes can help speed up queries. If your database includes raster datasets. you'll want to make sure you've built pyramids for all the rasters, so they'll display faster. Finally you can compact your database from time to time to decrease fragmentation of data on disk and make data searches faster. Defining or modifying a spatial index ArcGIS uses spatial indexes to quickly locate features in feature classes. Identifying a feature, selecting features by pointing or dragging a box. and panning and zooming all require ArcMap to use the spatial index to locate features. Feature classes in a geodatabase use a system of grids as the spatial index. When you zoom to an area in ArcMap. ArcGIS finds the features that fall within the grid cells covering that area and displays only those features—that way it doesn't attempt to draw all the features (even those off the edges of the screen). A feature class in a personal geodatabase has only one grid. Once a feature class is created in a personal geodatabase. you cannot modify the grid cell size. A feature class in a file or ArcSDE geodatabase can have up to three grids. The additional grids allow feature classes w ith features of very different sizes to be queried faster. However, for most feature classes only a single grid is necessary. ArcGIS automatically rebuilds the spatial index after certain operations, to ensure the index is optimal. However, there may be times when you want to manually recalculate the index or assign grid cell sizes of your own— for example, after adding many polygons that are much larger than existing polygons. □ _£=J_I U> |ormrxc r^~i <-> I To view, recalculate, or modify a spatial index, right-click the file or ArcSDE geodatabase feature class in the Catalog tree, and click Properties Then click the - Indexes tab on the Feature Class Properties dialog box, Creating an attribute index Once you have data in a table or feature class, you can create attribute indexes to speed up queries you make on geodatabase tables and feature classes. It is much faster for the database to use the index to look up a record than to start at the first record and search through the entire table. Attribute indexes can be created for single or multiple fields in a geodatabase feature class or table by accesstng the Properties dialog box in ArcCatalog. 2 • Geographic Data Management 1 mm * To create an attribute index, right-click a feature class in the Catalog tree and click Properties; then select the Indexes tab. I cw I «■» I Click the Add button to open the dialog box. Enter a name for the index, then use the arrows to add the fields you want to index to the list. These would be the ones you search or query frequently. Creating raster pyramids Pyramids are reduced resolution representations of your raster dataset used to improve display performance. With pyramids, a lower-resolution copy of the data displays when drawing the entire dataset. Using lower-resolution data allows the dataset to draw quickly, while display quality is not noticeably worse. As you zoom in. higher-resolution data is displayed; performance is maintained because you're drawing successively smaller areas. ArcGIS chooses the most appropriate pyramid level automatically based on the scale of the map. Pyramids only need to be built once per raster dataset; after that, they will be accessed each time the raster dataset is viewed. When you display a raster for which pyramids have not been built, you're prompted to build them. It's a good idea to do this. You can also build pyramids for a raster dataset at any time by right-clicking the raster in the Catalog tree and clicking Build Pyramids. «. 4* %rx = ■ * |iU«Wi |C.tfir—mlli'CMii P—cf^üC ««— 1 J • - ■ - .____-, -—j r 1' |n i tri i"1 a I »-»»» 1 Right-click the raster in the Catalog tree and dick Build Pyramids. This opens the Build pyramids tool—click OK to build the pyramids. Although you are not able to build pyramids on raster catalogs, it is possible to build pyramids for each raster dataset within the raster catalog. 146 147 Using ArcGIS Desktop 2 • Geographic Data Management Compacting and compressing geodatabases A file geodatabase is stored as a folder of files on disk, while a personal geodatabase is stored in a single Microsoft Access (.mdb) file. When you first add data to either of these geodatabases. the data within each file occupies a continuous space on disk and is accessed efficiently by the software. However, as you delete and add data over time, the data within each file breaks into increasingly smaller, scattered fragments as data is removed and new data is added elsewhere in the file. This causes the software to perform more data-seeking operations within each file, slowing the rate at which the data is accessed. Compacting rearranges how the data is stored in each file, consolidating the data so that it occupies a single, contiguous space. Compacting also reduces the size of each file—it's possible to be able to reduce the size of a geodatabase by half or more. If you frequently add and delete data, you should compact your file or personal geodatabase on a monthly basis. You should also compact a geodatabase after any large-scale change, such as deleting a number of datasets. <■. 4 * to p . <1 * n n? * v. • o * To compact a personal or file geodatabase. right-click the geodatabase and click Compact Database. File geodatabases can also be compressed to make them smaller. Compressing a geodatabase (especially a large one) can yield significant storage savings, which can be helpful when you're pressed for disk space or are trying to fit data onto a CD or DVD. Once compressed, a dataset looks the same in ArcCatalog and ArcMap as when it was uncompressed. The compressed data is a direct access format, so you do not have to uncompress it each time you access it—ArcGIS reads it directly. A compressed dataset, however, is read-only and therefore cannot be edited or modified, except for changing its name and modifying attribute indexes and metadata. Compression is best suited for datasets that do not require further editing. If required, a compressed geodatabase can be uncompressed to return it to its original, read-rite format. ,4« tjpx >, = ass e. a*a if? * *. *o«. 7b compress a file geodatabase. right-click the geodatabase and click Compress File Geodatabase. hi addition to compacting or compressing a geodatabase, you should also run the Windows disk defragmenter on an occasional basis to maintain overall file system performance. File and personal geodatabase performance can benefit from this operation just like other types of files can. The performance of an ArcSDE geodatabase can also become degraded over time as you add and delete features. That's because features that are deleted remain as rows in the geodatabase, but are only marked as "deleted" (so they can be undeleted, if necessary). To remove the deleted rows—and improve performance—you need to compress the database (any deleted rows can no longer be undeleted after the database is compressed). 1~ .„ To compress an ArcSDE geodatabase, right-click the geodatabase, point to Administration, and click Compress Database. 148 149 Data Compilation and Editing An overview of data compilation and editing • 152 Collecting, importing, and converting GIS data • 160 Collecting data in an ArcGIS format Compiling GIS data in other formats Compiling raw coordinate data Assigning locations using street addresses or routes «165 Geocoding street addresses Linear referencing Starting and managing an edit session • 172 Starting the edit session Managing the edit session Creating and modifying features • 176 Creating features Modifying the shape of a feature Changing the position of a feature Editing connected features • 181 Connecting line features Extending a line Creating an adjacent poiygon Editing features that share a vertex or border Creating features from a printed or scanned map • 190 Digitizing over a background image Digitizing from a printed map Creating features using vectorization Adding and editing attribute data • 201 Using the Attributes dialog box Using an attribute table to add or edit attributes Editing attributes for datasets having table relationships Adding fields to a table Creating and editing annotation • 207 Editing map document annotation Creating and editing geodatabase annotation Creating and editing dimensions * 218 Editing routes and geometric networks • 222 Editing a mute dataset Editing a geometric network Checking your data for errors • 230 Validating attribute values Validating relationship classes and network connectivity Validating topology rules Defining coordinate systems and projecting datasets • 237 Adjusting and integrating datasets • 240 Transforming, rubber sheeting, and edge matching datasets Copying attributes from one feature to another Combining datasets into a single dataset Editing multiuser and distributed geodatabases • 248 Editing an ArcSDE geodatabase using nonversioned data Editing using versioned data Creating and editing multiple geodatabase versions Creating geodatabase replicas for distributed editing Using ArcGIS Desktop 3 • Data Compilation and Editing An overview of data compilation and editing Once you've designed your GIS database, you need to collect the data that it will contain. The data you collect may be the most valuable asset in your GIS, since it underlies all the maps you'll make and analyses you'll undertake. While it's time consuming to collect data from various sources or create the data from raw information—not to mention making sure the data is as accurate and current as possible—the effort will ensure that your data, and the products you create from it, are sound. You may also need to process some of the data you collect—either before or after you put it in your database—to make sure you can use it to make maps and do analysis. You may need to correct or add individual features, add fields, update attribute values, change the coordinate system of a dataset, combine adjacent datasets into a single one, make sure coincident datasets register correctly, and so on. GIS data sources There are a variety of ways to collect the data that will go into your GIS database. In the course of your GIS projects—even for a single project—you'll likely use all of them. Get existing data in an ArcGIS format GIS data formats that ArcGIS can read directly include geodatabases. shapefiles, and coverages. You might get this from other ArcGIS users, download them from a GIS data clearinghouse, or buy them from a commercial data provider. You can copy this data right into your database in ArcCatalog, add it to a map in ArcMap, or use it for analysis with ArcToolbox tools (although you'll first want to verify the quality and usefulness of the data for your purposes—see 'The process for compiling GIS data' in this section). ArcGIS also recognizes a range of raster data formats (used for digital elevation models, orthophotos, and satellite images) you can load into your database or add to a map. ArcGIS datasets you're likely to acquire include geodatabases, shapefiles. images, layer files, and even map documents, all listed here in ArcCatalog. Get digital GIS data in another format and import or convert it While there is a huge amount of data available in an ArcGIS format, you may also come across GIS data that is in another data format. This might be data created in another GIS program, data from a related application such as CAD software, or data in a standard format used by a government agency or other organization (such as the digital line graph, . or DLG. format used by the U.S. Geological Survey). ArcGIS includes tools that recognize many standard formats and let you import the data into a geodatabase. You can even create your own tool to import custom formats. CAD data, including AutoCAD' drawing files (such as the building footprints, parcels, and road casings shown here) and MicroStation design files, can be imported to ArcGIS Convert tabular data to GIS data Some of the data you'll need may be for features that have a geographic location, but have not yet been assigned geographic coordinates so they can be mapped. Examples include a table of customers or students with a home address, a table of crimes with a street address or intersection, or a list of traffic accidents with a milepost marker. ArcGIS includes tools to read a street address or a measure along a route (such as mileposts), assign geographic coordinates, and create a feature class or shapefile from the data. You might also receive data as a list of features with associated coordinates, such as a table of earthquakes with a latitude/longitude coordinate, or a list of coordinates transmitted by a wolf wearing a GPS receiver and a radio transmitter. ArcGIS lets you import tables of coordinates—in various formats—and create a dataset you can store in your database and display on a map. ...» tt 3 f a**™.*** 4 Want* Miri-i 5 tWri mdStu« 12 Cur Food Me 13 CUjmtrty'i 36 Hn pit 5*m» a «nw it*,; tb um SupCTTiirai. I tri PEDMQMT AVE IC tön W PEACHTPEE ST HE ■*A5 3EVEPI» BTJ NE 311 tfSTHSTMLV 1233 PEACHTPEE ST NE 3E0 FORTUNE ST NE 151 AIDEN AVE Wir1 200 COOLE V st he IB9 HWflC'JTT ST km II DO CENTS? ST NW ■OD EIGHTH STHW SriETveL5TNW d SPRHG ST hftfV 120 kreMORWL DP se w r- .iE 1031 GENIES ST NW 10O1 CENTER ST WW TT MLLS ST NW 150 6TH ST NE 101 SAkEB ST NW 670 lOTH ST NW id VVUJAMS 5T NW TB AP&ONNE AVE NE iHGFflJJuetSSTNW SOD HAW* ST NE 39 )>tUS ST NW TOI JUMPED BT ME 1*1 .SThSTnE ~n ■:-- r -s 3D31B 30311 XBTE Elz S.r«t BUW 3D309 Sien i~ VE Rntjum 30316 So» raae uhUmh 30313 Smc*5u)E 3031» Rmmm 3035 t* 5*6*9 31 TO'SiC 3HS5.6Q Features stored in tables (such as this Excel table) and having a street address or other locator can be assigned coordinates and displayed on a map in ArcGtS- 152 153 Using ArcGIS Desktop 3 • Data Compilation and Editing Create GIS data from scratch in ArcGIS If you haven't been able to get the data you need in a digital format, you can create the datasets. In most cases, you'll draw features right on the screen in ArcGIS, using existing data (such as an aerial photo or satellite image) as a backdrop, guide, and spatial reference. For example, to create a dataset of streets as line features from an aerial photo stored as an image on your computer, you'd display the photo and trace over the streets to create the lines. If the information is on an existing printed map. you can trace over its features on a digitizing tablet to create a GIS dataset. This was the main method of data compilation in the early days of GIS, when most geographic information was in the form of paper maps. Now it's mainly used to fill in holes in your database when the data isn't available from any other source—such as for local historical data. Printed maps and aerial photos can also be scanned and then automatically convened to vector GIS datasets. ~3 / B a a ■ ;y-/\ i 020 ■ ■ KM ' :., i 022 * n C < - 006 - ::: AL - 006 ' nil? i 02* m > -3110-3 t 1 a a- J.- -- You can create features in ArcGIS by digitizing. In this example, the ArcScan for ArcGIS extension is used in an ArcMap edit session to create features (blue line) by tracing over a scanned parcel map. Make new data from existing GIS data Some of the data you'll require can be constructed or derived from datasets you've already loaded into your database. This might be a specialized dataset built from a collection of other features, such as a transportation network constructed from streets, highways, intersections, bus stops, and so on. Or. it may be a dataset you derive by processing an existing dataset—you might clip streams for your study area out of a larger dataset of streams, or you might process an elevation surface to create a raster dataset of slope steepness (see Chapter 5, 'Geographic Analysis', for more on processing datasets to create new ones). A surface showing steepness of slopes (below) can be derived from an elevation surface (left), using tools in ArcGIS. • . t □ * a * r-~. pTS -3IB-3 ■ ' ■ A- The process for compiling GIS data •Mil SMNfl* Compiling and editing GIS data is a loosely structured process that includes a number of tasks. You may not perform these tasks in just this order, but you'll want to make sure you've at least considered each of these points. You may also find that while building the database your various datasets will be at various stages in the process. And you may also find you'll have to revisit earlier tasks as new data is available. Keeping a GIS (or any) database current is an ongoing process. Developing a system to track your datasets and where they are in the process will be very beneficial (metadata can help with this, or even a spreadsheet). Set up a workspace structure and database design Before collecting data, you need to know what data to collect. Your database design process will result in a list of required datasets. Having the workspace structure or geodatabase in place will allow you to keep the data organized as you compile it. The section 'An overview of geographic data management' in Chapter 2 includes a discussion of how to set up a workspace structure and design a GIS database. Once you've completed the database design, it's a good idea to list—for all the required datasets—where the data is going to come from, if you know. That will help focus your search. For example, you may already know that some of the data you need is only on printed maps that you'll need to scan or digitize. You may be aware of some GIS datasets available from a local agency or that you will need to buy from a commercial provider. For other datasets. you may not know if they already exist—either in digital form or on paper— so you'll have to initiate a search. 154 155 Using ArcGIS Desktop 3 • Data Compilation and Editing Search for existing data Once you know what data you need, you need to find it and collect it one place. If you don't already know that it exists and where it is, you will need to search for it. There are several places where you can start your search. ESRI Data & Maps The ESRI Data & Maps CDs and DVDs contain basic global and national level data for parts of the world, such as hydrography, transportation networks, administrative boundaries, and demographic information (see the appendix in this book). These datasets are useful if you're working at a national or global scale. However, you may need more specialized data (such as vegetation types, air quality readings, or health statistics), or more detailed data (a coastline dataset. for example, is often very generalized for display on a national map), especially if you're working at a local or regional scale. GIS data clearinghouses There are several global and national G1S data clearinghouses set up on the internet (for example, www.geodata.gov). You can search by data theme or by location, or both. Some of the data is free, while other data you have to purchase. Again, the key is finding data that is detailed enough for your needs. Many states and regions have set up clearinghouses for local data. Data that you download or obtain may have restrictions on its use. You'll want to check this for all data you obtain, but especially data you download from a clearinghouse. Commercial data providers There are many companies that sell GIS data. Sometimes this is public domain data that a company has updated or corrected with newer or more accurate information (streets are a good example): or sometimes the company has compiled information from various sources in one dataset and used it to create new information, such as retail lifestyle categories for ZIP Codes. They may also process the data or use models to make predictions, such as projected population growth for counties. Some data you can buy is from companies that go out and collect raw data, such as satellite imagery or aerial photography. Commercial sources can be found at some of the clearinghouses, in GIS magazines and other publications, at GIS conferences, and by searching on the internet. Regardless of the source, you'll want to make sure you get information about the data: • The coordinate system it's in • The date it was collected, and when it was updated • For attributes, the descriptions of category codes and the units of measurement for numeric fields • The resolution of the data (the appropriate scale at which it can be displayed) • The owner of the data (if not the provider) and any restrictions on its use This is usually in the metadata documentation that either comes with the data or is available at the clearinghouse. But in some cases you'll get data without documentation, so make sure the provider gives you at least these basic details. Import or convert existing datasets, as necessary In many cases, the data you obtain will already be in one of the formats ArcGIS can directly read and use (a geodatabase. a shapcfile. an Arclnfo coverage, or a supported raster format). However, you'll probably get at least some data that is another GIS format, some other digital format, in a table with a geographic locator (such as a street address), or otherwise needing to be converted or imported before you can add it to your database and use it with ArcGIS. geodata.gov is a U.S. government clearinghouse where you can search for. and download, data and maps. Local or regional agencies Many local government agencies are willing to share their GIS data if you contact them directly. Some data you may have to purchase, usually at a relatively low price that covers the distribution costs. Once you start building your own GIS datasets you may find that agencies are willing to exchange data they have for data they need. A good way to find data is through local and regional ESRI user groups, many of whom hold regular meetings. Use ArcCatalog to import datasets. 156 157 Using ArcGIS Desktop 3 • Data Compilation and Editing Create additional datasets Once you've collected all the available data, you may still be missing some datasets you need. If there is source data—such as an existing printed map—you can digitize it. If not, you may have to collect the data in the field, or pay someone to do it. Or. you may have to substitute other available data that may not be your first choice (for example, lower resolution satellite imagery). Or. do without. Since similar data is often available from different sources, there will be decisions—and trade-offs- along the way. You may have to decide between obtaining an existing GIS dataset that is out of date (and either updating it or using as is), and digitizing a recent map to have the latest information. The first option is faster and less expensive, but you may end | up with lower quality data. Wake sure the datasets are integrated The next step is to make sure you can use all the data for its intended purposes. To do this, you need to make sure the various datasets you've obtained from various sources fit together. First, you'll want to make sure the datasets can all be displayed in the same geographic space. While they don't have to all be in the same coordinate system, they at least have to have a spatial reference defined so ArcMap can display them together on a map (ArcMap will project data on the fly). ArcGIS data should already have a spatial reference defined; if you've imported data, you'll have to define it. However, it's usually a good idea—at least for a database you're building for the long haul—to put all the data in the same coordinate system. It will minimize registration problems between datasets. and you won't have to worry about it as you're making maps and doing analysis. Then you'll want to make sure that the features in different coincident layers match up as closely as possible—for example, you don't want street centerlines stored in one dataset to cross over any parcels stored in another dataset Even if the features are in the same coordinate system, the data may have been collected by different agencies at different times and at different resolutions (or with varying quality control). Usually, you'll have more confidence in the accuracy of one of the datasets. You'll use this one as the control, and adjust the other datasets to match it. In the end. you may have to edit and move individual features, but adjusting one dataset to another can at least get the features close to the right location. Finally, to make sure the data covers your area of interest, you may need to match tiled datasets to build a continuous dataset for your study area. This is often the case for national databases stored in quadrangle sheets, such as hydrology or elevation data. Conversely, if you have a dataset that covers a large area, you may want to clip out the portion that pertains to your study area (clipping data is covered in Chapter 5—see 'Extracting a portion of a dataset'). Make sure the data has all the attributes you need During the database design process, you identified and listed all the attributes each dataset should have. The attributes will at least partially drive your search for data—if there are choices, you'll want to use the dataset that has more of the attributes you need. If you collected data from another source, you'll likely need to add attribute fields and assign values—for example, assigning your own paving codes to a street dataset you bought. If you're creating the data yourself, adding attributes is a major part of the process. □ .-> y * ■ <. > "3 .' pí a □ j a. • UK Attribute editing is done in ArcMap. You can update the attributes of existing features, or enter the attribute values for newly created ones. Make sure the data is as correct as possible It goes without saying that you'll want your database to be as error-free and up-to-date as possible, within your time and money constraints. The better your data, the better your maps and analyses, and the better the decisions based on them. The goal, of course, is to have your data reflect as accurately as possible what's actually on the ground. You'll likely spend some time editing both individual features and their associated attributes. You'll move features to the correct location or change their shape, connect features that need to be connected, add missing features and delete ones that no longer exist (or shouldn't have been there in the first place). ArcGIS has tools to check for errors and validate any edits you've made. Part of this involves checking the data against any topology or attribute rules you set up when you designed your geodatabase (see 'Ensuring spatial data integrity' and 'Ensuring attribute data integrity' in Chapter 2). As mentioned before, keeping a database current and accurate is an ongoing process. Create any extended or derived datasets Once you're confident in the quality of your data, you'll create any extended or derived datasets you need in your database. These might be datasets constructed from existing features, such as a bus route built from streets and bus stops, or a water system built from pipes, junctions, and pumps. You might also use geoprocessing tools to derive new datasets, such as creating a slope or hillshade surface from an elevation raster, or building watershed boundaries from an elevation raster and a streams dataset. Document the data Documenting your data is necessary so anyone in your organization who uses the data will know what they're dealing with. And it will be invaluable when you revisit the data at some point in the future. It's also critical if you end up sharing your data with other users, or publishing it on the internet. Documenting data is more efficient if you do it as you go along, working with each dataset. The metadata tools in ArcCatalog make it relatively easy (see 'Documenting your database with metadata' in Chapter 2). While metadata documentation can be extensive, you should include at least the basic pieces of information listed above under Search data sources for existing data'. 158 159 Using ArcCIS Desktop Collecting, importing, and converting GIS data A lot of data is available in a format ArcGIS can use directly (shapefiles. geodatabases, coverages, rasters, and some CAD data). This is especially true of basemap dLit.i such lis hydrology, street networks, elevation, administrative boundaries, and so on. You may get data, though, that is not yet in a format ArcGIS can use. Or, you may want to convert ArcGIS data to another format to share with other GIS users. ArcGIS Desktop lets you import or export a wide range of both feature and raster data. Collecting data in an ArcGIS format You can add data to a map—or use it in an analysis—from any source or workspace you've connected to if it's already in ArcGIS format (see 'Finding and connecting to data' in Chapter 2). You may want to copy the data into your own workspace. Use the copy and paste functions in ArcCatalog to copy data to the location you want. The data can only be copied to an appropriate destination location (the Paste function will be grayed out if you can't copy the data to that location). Alternatively, you can click and drag datasets in the Catalog tree. Shapefiles, geodatabases, tables, and images I can be copied from one folder to another. Feature classes can be copied from one geodatabase to another. Once you've connected to a data source, or downloaded data from the Internet, copy the data into your project workspace or geodatabase. Right-click a dataset and click Copy, then nght-click the destination and click Paste. Shapefiles. tables, and images can't be directly copied into a geodatabase. but rather must be imported. Conversely, data held in a geodatabase can't be copied to a folder, but must be exported to another format (for example, you'd export a eeodatabase feature class to a shapefile). 3 * Data Compilation and Editing Right-click a geodatabase to import a shapefile {use the Feature Class option), table, or raster. The "multiple" options let you create a list of datasets to import at one time. Right-click a feature class or other geodatabase dataset to export it to a format outside the geodatabase (or to another geodatabase). You can also export shapefiles, tables, and rasters to other formats by right-Clicking them in the Catalog tree. Arc Toolbox contains a number of tools that also perform these (plus other) import and export operations to convert ArcGIS and related data between formats. For example, you may want to convert a dataset of soil type polygons to a raster dataset to use in analysis. The tools are particularly useful for converting data within a script or model. $ Hannai CAD Orrctabor ^ burnt Qnnraga ArroUDcn Lspart from CAD / "/oitt To Geodät abate (mobrjfel t TaUetoLVodaUbaMfrtulTia) n«j Inda | Seart | The Conversion Tools toolbox contains toolsets for converting between a variety of feature and raster formats. 160 161 Using ArcGIS Desktop Compiling GIS data in other formats ArcGIS Desktop lets you work directly w ith a number of other, non-ESRI geographic data formats. You can add a w ide range of image formats to your ArcCatalog workspaces and can add the data to a map in ArcMap to display it. These include common raster formats such as DEM (used for digital elevation models), various ERDAS* formats (used for satellite images), and MrSID* (a compressed raster format often used for very large datasets), as well as common graphic formats including BMP. TIFF, JPEG, and GIF. A complete list can be found in the "Data Support in ArcGIS' section of the Desktop Help. «9fli • ss I- si*!"*?"* «. a* % p x aa•- * « « ArcCatalog recognizes and displays image data, such as this satellite image in ERDAS format (above) and an aerial photo in TIFF format. These images can also be added to maps in ArcMap and displayed with other data, with no data conversion required. Cam p*-*- 1"---\ * IM I .Sir™" - Similarly, ArcGIS Desktop recognizes several common CAD formats, including AutoCAD DXF and DWG formats, and MicroStation* DGN formats. You can manage the CAD drawing in ArcCatalog, display it on a map in ArcMap. or use it with many of the tools in the toolbox for analysis or other geoprocessing tasks (however, it can't be edited in ArcGIS unless you import it into a geodatabase feature class or shapefile). Each layer in the drawing is displayed as a I separate layer in ArcGIS Desktop (even though they're part of a single entity—the CAD drawing). In some cases, you may want to convert a single layer in the drawing to an ArcGIS dataset (shapefile or feature class)—you may only need that layer for your maps or you may need to edit it for use in analysis. Right-click the layer in the Catalog tree, point to Export, then click the format you want to export to (geodatabase feature class or shapefile). Alternatively, you can use the conversion tools in ArcToolbox. 3 • Data Compilation and Editing ArcGIS supports other feature data formats through the ArcGIS Data interoperability extension. The Quick Import and Quick Export tools in the Data Interoperability toolbox in ArcToolbox allow you to import data to a geodatabase feature class from a wide range of vector formats, including DLG, MIF. MGE. and many others. The Data Interoperability extension also allows you to create custom converters. On the Quick Import dialog box, specify the geodatabase that will hold the imported data, and click the ellipses to specify the input dataset. % 3D Wtap/O r«fe ^ Cav^aon To* % Data intefopenbiiy Took ^ QiJ& Export 8Cm Marwjment Took ^ , r-s ? rfcrcrtrc loub % Smfcal J>™.yn Took % aaOsfeo Toot Fwf |lnd»i» | S—chl Quick Import is located in the Data Interoperability Tools toolbox (you must have the Data Interoperability extension licensed and enabled)- a :BCMO€P MOEP BCMaFEltcmr.SiJbnvHKiiiFoi'nH-F ES*_FT> FKMoTE*CTcraS<*miiMrjri Fom».« ESF.ftCSULTS P-- On the Specify Input Data Source dialog box. click the ellipses next to the Format box to open the Formats Gallery. Choose the format from the Est, then, on the dialog box, enter the input dataset name (or browse to it). -J=_i-ä=J_l_J 162 163 Using ArcGIS Desktop Compiling raw coordinate data Some CIS data may be in tabular or list form, but have geographic coordinates associated with the features. Often this is data that has been directly captured in the field using GPS or another device. GPS units calculate their position using signals from satellites (and sometimes base stations). If you have a table of point features with associated x,y coordinates, you can import the data to a layer in ArcMap, and then create a dataset by exporting the layer (see 'Adding data to a map' in Chapter 4). You can also stream coordinate data directly to ArcMap via a GPS connected to a laptop computer or Tablet PC running ArcGIS Desktop. By capturing the streamed coordinates in a log, you can save them as point or line features in a geodatabase feature class or shapefile. Use the GPS toolbar in ArcMap to input data directly from a GPS unit (click View, point to Toolbars, and click GPS).__ —ITT The GPS Position window shows you your real-time position, altitude, speed, and heading using the GPS input. m, - k r i.- a- — ~3Fi-a ■ ' ■ A- »- r |l CÖKK ^ OutD^M i'i suae tf^m Use the Log Setup dialog box to create a new log to capture GPS data points as a shapefile or geodatabase feature class. You can specify (he streaming options, such as how often to capture coordinates, or a minimum sampling distance. When you create a new log, you specify which fields to include—these will become the initial fields for the shapefile or feature class. 164 3 • Data Compilation and Editing Assigning locations using street addresses or routes ArcGIS includes tools to read a street address or a measure along a route, assign coordinates, and create a geodatabase feature class or shapefile from the data. The process of assigning coordinates using an address is called geocoding. Geocoding is mostly used to assign locations on a map to a table of features that have a street address, such as customers, students, businesses, or even crime scenes. Linear referencing is the process of assigning locations to features—usually events, such as accidents—along a route dataset, using measurements such as distance from mile posts. Geocoding street addresses To geocode a table of addresses, you need reference data (usually a dataset of streets with address ranges for each block). The reference data is used to create an address locator that can be used to match the addresses (see 'Adding specialized datasets to a geodatabase' in Chapter 2). This table of customers includes a street address that can be used to assign coordinates and create point , . . . This dataset of streets has been prepared for use in geocoding. The elements of the address have features. The features can then . ,. , , r, ~ . , , . * * ■. w- , * - m- A m- been placed in separate fields, and include the address range for each street segment for the eft be displayed on a map or used in , \~7, ,\. . , ,L , .- . „ n i SjS and nght sides of the street, the prefix direction, prefix type, the name itself, the street type, suffix direction, and the ZIP Code on both the left and the right side of the street. AH these elements are used to find as close a match as possible for each street address in the customer table, An address locator specifies the reference data to use, as well as parameters and queries that direct the matching process. For each address in the table, ArcGIS attempts to find the best match against the reference street features stored in the address locator. When it finds a match, it assigns coordinates to a new feature in the output dataset. The coordinates locate the feature to the correct side of the street and in the best estimated location based on the street number and the range of addresses for that street segment. So an address of 150 W Elm St. wrould be located halfway along the 100-200 block of West Elm Street. The Address Locator specifies the reference data (street dataset) and the names of the fields in the dataset containing the various address elements. It also lets you set the matching options and additional output fields in the output dataset Address locators can be created in a folder (workspace) or within a geodatabase, and can be used with shapeWes or feature classes. \UJJX ■ |l_t>C0 |b.t_*dd j | pre fbi ■ ■ |MME j : Jam. : ■- fan 165 Using ArcGIS Desktop You can geocode in either ArcCatalog or ArcMap. Right-click the table containing the addresses in the Catalog tree (ArcCatalog) or the table of contents (ArcMap). T To geocode in ArcCatalog. in the Catalog tree right-click the table containing the addresses, then specify the address locator to use. __..~%rm„ 1-B=== 3 *.»n p "3FT-3 I To geocode addresses in ArcMap. add the table containing the addresses to be geocoded, and the streets (optional) to your map. Right-click the table (select the Source tab to see it in the table of contents) and click Geocode Addresses. Use the Add button on the dialog box to specify the address locator to use. 3 • Data Compilation and Editing In the dialog box. specify the field In the table that contains the street address (if it's a standard name-such as ADDRESS—it will be selected automatically) Also specify the name and location of the output dataset that will be created. Click OK when you're ready to geocode the addresses. JO. JJiJ IS- i r ■■.— T-. •-• .- in» mir i ti- •* 1 J 1 .iu mudQK—W Oi—i. 1 m 1 « 1 Cm. J There may be more than one possible match for an address. Each potential matching street candidate is assigned a score based on how closely it matches the address, and the address is then matched to the candidate with the best score. The more complete the addresses in the table (with correct prefixes, street types, name spellings, and so on) and the more accurate your streets dataset. the better the results. After running a first pass you have the option of relaxing the parameters and re-geocoding the addresses that didn't match, or matching addresses interactively. When the geocoding is complete, the Review/Rematch Addresses dialog box is displayed (in ArcMap. the new features are also added to the map). The dialog box tells you how many of the addresses in the table were able to be matched. It also lets you modify the geocoding options (click Geocoding Options) and rematch the addresses that didn't match the first time. •raii'rw ova**!* You also have the option of matching addresses interactively (in this example, there were two possible matches—you can use the dialog box to select the correct one). I .il i. w 15" — " Swainnntii EfrfoM [3 » ;l..... O IWilcamkMxn 1 mijm* 1 1 I m 1 ,\ Hp*. 1 «o xn 1 'p-ia^^ :L'iHiMiimim,ai J p»ae«ia» wi| Zn -- Huay [ 'ICmiIIIIIWMI«>nriNEI»30l torn 1 Mr> F FMOV* 1 PwTairt 1 l.iaHa—1 1 r«l 1 MM1 1 UjC«i IV***1 i i pw— i mm iwww t lie nana ft—■» j 2™* Mta | Oap - ( «. j —.-1 4 LVse the Geocoding Options dialog box to temporarily override the settings in the address locator, if necessary. 166 167 Using ArcGIS Desktop You can also rematch addresses later, in etther AreMap or ArcCatalog. To rematch in ArcMap use the Tools menu, or right-click the results in the table of contents. To rematch addresses at a later time, dick the Tools menu, point to Geocoding. click Review/Rematch Addresses, and select the geocoded result feature class you went to work with. (You can also njn the initial geocoding from the Tools menu.) Or. right-click the result in the table of contents, point to Data, and click Review/ Rematch Addresses (as shown above). rematching addresses. a - FcToatoa - . i 1 WrssTaob . i 1 i:*rogr«rnr took - i ^ CtfMfflon Took - i h. &»M Inten**» »t*v • ( ^ LuUHSTLsgsnHTie Toots _ f ^ Cre^*fc*»s louts ^ Otacodc Afkressn /> BefrJd Ltx*cr ^ RanSdi fcS*eSJ*i • §5pttd*v*dToelt • h 5p*J i< «stxi Ion» j 3 • Data Compilation and Editing Linear referencing If you have a route dataset you've built from other features (streets, intersections, and so on) you can add data from an existing tabic that contains measurements along the route (see 'Adding specialized datasets to a geodatabase' in Chapter 2 for more on creating route datasets). The records in the table are referred to as events. The measurements are used to locate the events and display them on a map. Events can be points (such as accident locations) or lines (such as sections of highway with poor paving condition). Departments of transportation, for example, often create and maintain such event tables. The measures can be distance from the beginning of the route or markers along the route, such as milepost numbers. Route events are added to a map in ArcMap. You can then symbolize or query the events as you would any other features. Point event tables must contain the route ID of each event (which route it's associated with) and a measure along the route, such as the distance from the start of the route. Before adding the events, add the route dataset and the event table to the map. To add route events to a map, select Add Route Events on the Toots menu. A point event table contains the route ID. the measure along the route, and any other attributes associated with the event— in this example, the events are automobile accidents that occurred along highways. In the dialog box, specify the route dataset and Held containing the route ID, Then specify the event table and the fields containing the route ID and mute measure. The Geocoding Toots toolbox contains tools for geocoding addresses. To rematch the addresses in ArcCatalog, right-click the output dataset in the Catalog tree and click Review/Rematch Addresses. 169 168 Using ArcGIS Desktop 3 • Data Compilation and Editing Once added, the route events are stored with the map document. To save the events as permanent features, export them to a dataset. The Bvents (accidents) are added as points on the map, along the routes. To save them as features in a dataset. right-click the events layer in the table of contents, point to Data, and click Export Data. Line events must have fields containing the start point and an end point, in addition to the route ID. In the example below, the start and end points are represented by a "from milepost" field and a "to mileposf' field. Events can also be added by right-clicking the event table in the table of contents and clicking Display Route Events. ^■1 nnfci*»«f Jrouiii J Line event tables must contain fields for the start and end points (milepost markers, in this example), as well as the route ID. To add line events, specify Line Events as the type, and enter the fields containing the start and end points. The line events are added to the map as a new layer. Export the events to save them as a dataset. HHrljHflHj The route events (representing sections of highway with poor paving condition, in this example) are added to the map. The Make Route Event Layer tool in the Linear Referencing Tools toolbox performs the same function as the Add Route Events tool in ArcMap. It's useful for assigning locations to events within a script or model. The Linear Referencing toolbox contains a number of other tools for working with routes and route events. Make Route Event Layer is found in the Linear Referencing toolbox in A re Toolbox. -34 -3 -3 4 .... 1^— F- 170 171 Using ArcGIS Desktop Starting and managing an edit session At some point in building and maintaining your database, you'll need either to correct errors you discover in the data or update the existing data with newer information. For example, you may need to modify the shape of a road that's recently been surveyed, or update a parcel that's been split. You do this by editing the geographic features interactively a in ArcMap. Many of the same editing tools are also used for creating new features—either in a new, empty dataset or in a dataset containing features, such as adding a new subdivision to a parcel dataset. The editing tools and settings are located on the Editor toolbar—you need to open the toolbar in ArcMap before editing. You use the toolbar to start an edit session, add or modify features, save your edits, and end the session. During the edit session, other ArcMap functions are still available—adding layers to the map. zooming, panning, changing symbology I of features, and so on. The only difference is that layers are available for editing, as long as the edit session is open. As you edit the data, even though the data appears as a layer in ArcMap, you're actually editing the underlying data source. After you close the edit session the layers can no longer be modified until the next time you open an edit session. Starting the edit session Once you have added the data you want to edit to a map in ArcMap. you'll open the Editor toolbar and start an edit . Editor Toolbar button mmm B> t» t~ r« üw™ is** t»rt- 9* □ at B • B > - * |ü» 3 k □ w **■ - 'F~~3 • • a 7b start an edit session, click the Editor Toolbar button to display the Editor toolbar. Then click the Editor drop-down list and click Start Editing. WS ^^^^ , - k , □ - A - :■: 1* <* i Carol ■J I SrJtdPs I You might see one or both of these windows when you start editing. You 'II see the one on the left if the datasets you've added to ArcMap reside in different geodatabases or folders. You can only edit the data in one workspace (geodatabase or folder) at a time (you can still display and snap to all the layers on the map). You'll see the window on the tight if the coordinate system of any of the datasets you're editing is undefined or does not match that of the map (defined by default as the coordinate system of the first dataset you add to the map). Next you'll choose the workspace and data frame (if more than one) containing the datasets you want to edit, and choose the target layer (the one you'll be working on) using the Target drop-down list—you can switch between targets during a single edit session. You'll probably also want to set the snapping environment, to make sure new (or modifier features snap to existing ones—this ensures features connect to each other correctly. d) 3 ■ Data Compilation and Editing «i Use the Target drop-down list to select the dataset 1_° I (o which the edits will be applied (the list contains only those datasets in the geodatabase or folder you specified). You can switch between layers during an edit The Snapping Environment dialog box lets you specify which layers can be snapped to as you're creating or modifying features. All the layers on the map are available for snapping Use the check boxes to specify for each whether features can be snapped to vertices, edges (lines or polygon borders), or end points of existing features. Features will snap to existing features in the same layer or another layer. You can access and change the snapping settings anytime during an edit session. The Source tab on the table of contents is useful if your map contains datasets stored in different folders or geodatabases—it shows you which layers are in which. During the edit session, you can use the Undo button (on the Standard toolbar) to undo your last action. Use the Editor drop-down menu to save your edits. Just saving a map document does not save the edits to the features—you need to specifically save the edits in your edit session. You can choose to quit an edit session without saving your changes. Managing the edit session ArcMap includes several options for making your edit session more efficient. Open a magnifier window to get a closer view of a small area without changing the map extent. Click and drag the window over the area you want to magnify. To open a magnifier window, click Magnifier on the Window menu. zl J. *.»□ w a i-1-1 a Click the title bar and drag the magnifier window—center the crosshairs over the area you want to magnify. When you release the mouse button the area under the window is magnified. _... -awf 172 173 Using ArcGIS Desktop When you release the mouse button, the area under the window is magnified, centered on the crosshair. You can move the magnifier window and drag it while holding on to the same sketch or modification already in progress. Use the dropdown menu to change the magnification level. You can also set the window to magnify as you drag it—select Update While Dragging from the pull-right menu. In this mode, the magnifier window is like moving a magnifying glass over the map. Use the drop-down menu to change the magnification Click Update While Dragging to use the magnifier window like a magnifying glass Many editing functions have keyboard shortcuts associated with them, including those on the context menus. These can minimize the use of your mouse and speed up your edits. For example, with the Sketch tool active, you can press the F6 key to quickly enter the coordinate location of the point or vertex you want to place. See "Getting started with editing' in the Desktop Help for a list of keyboard shortcuts. Sometimes you may need to enter lengths or other measurements in units different from your map units. In many dialog boxes throughout the editing environment that require you to enter a distance value, you can specify values in a different unit of measure by simply typing a unit abbreviation after the number. For example, if your map units are feet, by default. ArcMap will assume any distance values you enter are in feet. However, you can simply add "m" after your input value so ArcMap know s you the value you entered is actually in meters. 3 • Data Compilation and Editing ~~3 J w ~~3 -mt^r- ■ If you need to enter distances in a measurement unit other than the one the map is in. simply type an abbreviation for the unit after the distance value. In this example, the map units are meters, and the distance is entered in feet (ft.). ArcMap does the conversion on-the-fty. Click Options on the Editor drop-down menu to access settings for the edit session. You can set the snapping tolerance, specify the symbol to use to highlight selected features, or customize the Tasks list, and so on. Click Options on the Editor menu to access the settings for the edit session. J_=!_ The Generel tab lets you specify the snapping tolerance, in pixels or map units. Make the tolerance larger if you're having trouble snapping to any feature; make it smaller if you're having trouble snapping to the correct feature. The Topology tab lets you specify the symbol to use for selected topology elements—click a symbol on the tab and use the Symbol Selector dialog box to change the color and size of the symbol (see Chapter 4 for more on map symbols). The Edit Tasks tab lets you rearrange or remove tasks from the Task list on the Editor toolbar. If you specify a sticky tolerance distance (on the General tab), when you move a selected feature, the feature will stay put until the cursor has moved the specified distance—this helps you avoid inadvertently moving a feature. The options for adding segments and vertices can also be accessed using keyboard shortcuts (such as Ctrt+L to enter a length). Shortcuts can be more efficient than using the menu, especially if you're entering many vertices by typing angles and distances. 174 175 Using ArcGIS Desktop Creating and modifying features 3 • Data Compilation and Editing There are many different editing tasks you'll need to perform, and there are often several ways to complete the same task. This section presents a few of the most common ways to create new features, modify the shape of an existing feature, or reposition features. See the Desktop Help for additional tasks and a full discussion of editing options. Creating features To create either point, line, or polygon features you set the Task to Create New Features. The type of feature you're editing is determined by the Target layer—the dataset you're creating the new feature within. ~3 J. »»o v 1 '- • i ■ A- »-J.-±- The Task drop-down menu lists the most common edtiing tasks you'll do. Specify Create New Features to add features to an existing dataset or to a new. empty dataset. For point features, you'll click the Sketch tool on the toolbar, and then click on the map to enter the location of the point. ... - ... ■ "t - The Sketch tool ""^ Oil Click to create the point feature 1 1 iiimiiiiiii - 1 wt * To create a point feature, click the Sketch tool, then click where you want to place the point. The point feature you created is the currently selected feature—right-click it for options. Creating line and polygon features involves creating a "sketch" which is a temporary representation of the feature showing the segments and vertices. When you create the vertices in a sketch (typically, by clicking with your mouse), the segments between vertices are added for you automatically. Once you're satisfied with the shape of the sketch, you need to finish the sketch to complete the feature's geometry and actually create the feature. There are several ways that vou can finish a sketch, including double-clicking with your mouse, choosing the command from a context menu, and using a keyboard shortcut (F2). There are also a variety of options for entering vertices, in addition to clicking with the mouse. To add a line feature, click the Sketch tool, then click the location of the start point. Click to add each vertex and define the shape of the line. The segments between vertices are drawn automatically. The last vertex you added is shown in red. -IBlMl Right-click while adding vertices to a line or polygon and you get options for adding the next segment or vertex, as well as for finishing (or deleting) the line. The same menu can be displayed for point features, but most of the options are not available. These options let you add a segment or vertex by entering a distance, angle. xry coordinate pair, and so on. Type the values, then press the Enter key to add the vertex. These options let you add a segment parallel or perpendicular to a selected feature. Use these options to delete the current sketch or finish it and create the feature. c nam i«bx "3 * a »□ w =3 * Q- 7b create a polygon feature, click the Sketch tool, click a starting point, and add vertices to define the shape of the polygon. As you add vertices, a segment rubberbands from the iast vertex added to the start point to maintain the closed shape When creating polygons or lines, right-clicking a vertex will display more options. To finish the polygon, right-click and click Finish Sketch, or just double-click. 176 177 Using ArcGIS Desktop 3 • Data Compilation and Editing In addition to the Sketch tool, other tools are available from the Editor toolbar to add point features or line vertices and segments using arcs, distance, and so on. You can switch tools at any time while creating a sketch. Intersection Midpoint Distance-Distance ' ,4? «"3 Create Nsmi Featlie —Arc - Tangent -End Point Arc - Trace The Sketch tool lets you add a point or vertex by clicking a location. The dropdown menu next to the tool displays the Sketch Tool Palette, which lets you select other tools for creating points and vertices. Direction -Distance The tools let you create curved segments; create a segment by tracing over an existing feature (with an optional offset distance—useful for creating parallel lines); place a vertex at the midpoint of a line you draw, or at the intersection of two lines; or create a vertex at a given distance and direction. Modifying the shape of a feature To modify' the shape of a feature, the feature must be currently selected—use the Edit tool to select the feature. To modify the shape by moving a vertex, set the Task to Modify Feature. (Double-clicking a feature selects it and sets the Task to Modify Feature so you can start editing vertices—one of many editing shortcuts.) To move or delete a vertex, use the Edit tool to select the feature you want to modify, and set the task to Modify Feature. Click and drag a vertex to move it, or right-click it and click Delete To insert a vertex, place the cursor where you want to add the vertex, right-click to display the context menu, and click Insert Vertex. 178 You can also reshape a line or polygon using a sketch. Set the Task to Reshape Feature. Make sure the first and last segments of the sketch intersect the feature you're reshaping. Vertices will be added where the sketch intersects the feature, and the sketch segments you draw will replace the segment(s) of the feature between these vertices. To use a sketch to modify a feature, use the Edit Tool to select the feature, and set the task to Reshape Feature. Click the Sketch tool (or any of the sketch options) and add vertices, making sure the first and last segments intersect the feature you're reshaping. Changing the position of a feature When you click Finish Sketch, the segments you drew are added to reshape the feature. To move, copy, delete or rotate a feature, first select it using the Edit tool. To move it, click and drag it to a new location. To copy a feature, right-click it and select Copy, then right-click again and click Paste {or use the Windows standard Ctrl+C and Ctrl+V). The copy is placed on top of the original feature, but is currently selected—drag it to a new location. To delete a selected feature, right-click and click Delete, or press the Delete key on your keyboard. To rotate a selected feature, click the Rotate tool on the Editor toolbar. Then click and drag the cursor—the feature rotates around its center. To move a feature, select it using the Edit tool, then click and drag it. 179 Using ArcGIS Desktop 3 ' Data Compilation and Editing Right-click a selected feature to delete it, or to copy and paste (feature attributes are also copied}. To copy and paste between layers, set the Target to the layer you're copying from, and Copy: then set the Target to the layer you're pasting into, and Paste. _ mm □ SCO* X % ■ X " ■ * J iAtUW J! * - »1 i -___--—n-:-1- 4 ffofale « ft 1 1 ... 1 Cffc* the Rotate tooK then drag the cursor to rotate a selected feature around its center, or press A on your keyboard to enter a specific angle. Editing connected features You can drag a box to select multiple features, or hold the Shift key while clicking. You can then move, copy, or delete the selected features. Whether you're creating features in a new dataset or adding features to an existing one. at some point you'll likely need to edit lines that connect (or should connect)—such as connecting a new road to an existing one—or to create adjacent polygons that share a border—such as parcels or administrative boundaries. You might also need to move a shared vertex or border, thereby moving or reshaping the connected features. You perform these tasks in an edit session in ArcMap. Connecting line features To add a line that connects two existing lines, you snap the end points of the new line to the existing lines (either at a vertex or anywhere along the edge). You may also need to split the existing lines where the new line connects, to create intersections (for example, if you'll be using a dataset of streets for routing delivery trucks). Make sure the task is set to Create New Feature and the Sketch tool is active. This end of the line connects to a vertex on the existing line—move the cursor over (or near) the vertex, right-click, point to Snap To Feature, and click Vertex. The other end of the new line connects to an existing line where there is no vertex. Place the cursor over the line, right-click, point to Snap to Feature, and specify Edge as the feature to snap to. (Attemativeiy. you could set the snapping environment to Vertex and Edge for the streets layer; then the new line will snap automatically, which is more efficient if you're adding many lines.) 180 181 Using ArcGIS Desktop 3 • Data Compilation and Editing ~B ,/ a • n w Right-click the vertex you added and click Finish Sketch to finish the new line. Next you'll split the existing line where you connected. First, set snapping to Vertex and Edge for the streets layer. That will ensure the line gets split at the right place—right at the vertex where the new line connects. "3PT3 ■ / ■ a* * * When you select the line on the right, you can see that the original line has indeed been split. You'd split the first line that the new line connects to in a simitar manner. Extending a line You can extend a line to connect to another line. One way to do this is using the Extend tool on the Advanced Editing toolbar. □ at n • I * a > Tillen» ~3 ra o M__ Click the Editor drop-down list, point to More Editing Tools, and click Advanced Editing -E[^~3 » / t a- »■ ■£• -i- C//cA (he SpM too/ on /he too/bar. p/ace /he cursor over the vertex, and click to split the line. (You could also have split the line first, then specified Endpoint when using Snap To Feature to add the new line.) 182 183 Using ArcCIS Desktop * u m »• r > « ' .if* 3 71H +- -f *crrr do ~E)WD • I • a- Select the line you want to extend the other lines to, using the Edit tool on the Editor toolbar. When you do. the tools on the Advanced Editing toolbar become available. : * y • i * b x -- + 3 :/ *• * a w ^ a ■fc,- **i» fcjrrena 1001 * '21 —3f~3 ■ / b a- *' j£t ■ Click the Extend Tool button, and click the line you want to extend. * * ■ ~3 -J w ~3F-~3 ■ / 1 A- i- 7"ne fine extends and snaps to the selected line. Point to any other lines you want to extend (you can keep extending lines as long as the Extend tool is active). To stop, select another toot, or select the Edit tool (on the Editor toolbar). 3 • Data Compilation and Editing Creating an adjacent polygon To add a polygon adjacent to an existing polygon, you simply make sure the sketch for the new polygon crosses the existing polygon at least twice. : »■ a • « - -3 -3 Make sure the task is set to Auto-Complete Polygon, and set snapping to Vertex for the polygon layer you're editing. •I B □ I Click to end Click the Sketch tool and click the vertex on the existing polygon where you want the new polygon to connect. Continue adding vedices using the Sketch tool (or any of the other options for adding vedices). then click a vertex on the existing polygon to close the new polygon. Double-click the vertex to finish the sketch (or right-click and click Finish Sketch). The shared border is automatically added to the new polygon to complete it. 184 185 Using ArcGIS Desktop Editing features that share a vertex or border If you want to move a vertex at which two or more features connect and have them all adjust accordingly, you need to establish a topology. A topology makes explicit the connection between features. This allows you to move a vertex to which several lines connect (known as a node) and have all the line end points move with the node—without the topology, moving the vertex would move only the end point of the selected line while the endpoints of the other lines remained in place. One way to establish a topology is within a geodatabase. usually as part of the geodatabase building process, as described in Chapter 2 (see 'Ensuring spatial data integrity'). A geodatabase topology is stored with the data and is in effect on any map the data is added to. Sometimes—even if a geodatabase topology doesn't exist for a dataset—you want to be able to make a topological edit for that dataset. If a geodatabase topology has not been defined for the dataset, you can create what is known as a "map topology" in ArcMap. The map topology is stored only with the current map—not with the data. 3 • Data Compilation and Editing II the datase you re edtttng does have a geodatabase topology defined, you add the topology to your map. and then use the tools on he Topology toolbar to edit the connected features. Editing connected features in a geodatabase toSogys the same as for a map topo.ogy-for fines connected at a node, click the Edit Topology tool, select a node, and dr g h to ■ a y -3 ~H il *■ • n *r 3 Map Topology button a- .£• _1- To use map topology to edit connected features, point to More Editing Tools on the Editor toolbar, and click Topology The Topology toolbar opens. Click the Map Topology button, and check the boxes for the layers you want to add to the topology. (*, - e - |o«-*,Mn 3 w3 ' ran Topology Edit tool r .> 3 » * £ ■ ■ -. > Click the Topology Edit tool on She Topology toolbar, then click the node you want to move, to select ft Click and drag the node to Us new location. The end points of the connected lines move with the node, but the other vertices of the lines stay put. 186 4 * .-'.a s a Bit» ~3 tl «r? 3 To edit connected features using a geodatabase topology, add the topology to your map. ~3r°~3 ■ 11 a- »■ j,- j.- You'il be prompted to add to the map the feature classes that participate in the topology—click Yes. When you open the Topology toolbar, you'll see that the topology you added is listed. You'll also notice that additional tools are active that are not available for map topology—specifically, tools that let you validate your geodatabase topology rules (these tools are discussed later in this chapter). 187 Using ArcGIS Desktop You also use the Topology Edit tool lo move or reshape a shared boundary between two polygons that participate in a topology {either a map or geodatabasc topology). While the shared boundary looks like a single line, that line is. in fact, stored with each polygon. If you moved the boundary without having created a topology, only one of the lines would move, creating either a gap or an overlap. Add the geodatabase topology to the map. or use the Map Topology button on the Topology toolbar to make sure topology is turned on for the polygon layer. Modify Edge a ■ 1 dick the Topology Edit tool and select the border you want to mortify. The Show Shared Features button displays a list of features that share the border. Click a feature on the list to flash it on the map and confirm it's the one you want to edit (the check boxes determine which features participate in topology edits). Set the Task to Modify Edge under the Topology Tasks group: or just double-click the selected border—the Task is automatically set to Modify Edge. Once the task is set. the vertices for the shared border are visible. 3 * Data Compilation and Editing Click a vertex and drag it to a new position. You can also reshape a shared border—using a sketch—by setting the task to Reshape Edge. When you're done modifying the border, right-click a vertex and click Finish Sketch- pa—**.. When you finish the sketch, the new shared border is displayed. If you select the polygon, you can see its new shape. You can use map topologies and geodatabase topologies concurrently. The active topologies appear in the drop-down list on the Topology toolbar; you can switch between them during an edit session. 188 189 Using ArcGIS Desktop Creating features from a printed or scanned map You'll likely obtain most of your GIS data already in an ArcGIS format, or by importing it or interactively creating it on-screen. However, in some cases, the data you need may only be available on an image, such as an orthophoto, satellite image, or scanned map. While the image is in raster data format (pixels), what you may want to create are vector features—points, lines, or polygons. ArcGIS contains tools for tracing over an image on-screen to create geographic features—a process known as digitizing. In other cases, you may need to create features in the GIS from a printed map. You can digitize the map using a digitizing tablet, or scan the map and automatically create geographic features. These tasks are all performed in ArcMap. Digitizing over a background image You can use a scanned map or drawing, aerial photo, orthophotograph. or satellite image as a background in ArcMap, and create features (such as streams, roads, or building footprints) by tracing over the objects in the image. Some aerial photos and satellite images are already spatially referenced—that is. the extent of the image in geographic space is known. If this is the case, you can simply use the editing tools described in the previous sections to trace over the image and create features—the new features will be stored in x.y coordinates in geographic space. On the other hand, if the image is in page or screen units—likely the case for a scanned map or drawing—you need to place it in geographic space (see 'GIS data concepts" in Chapter 2). This is known as georeferencing, and is performed by associating locations on the image (control points) with the corresponding coordinates in geographic space. You can type the coordinates (if known) or create a link between a control point on the image and the corresponding location on an existing spatially referenced dataset. There is a range of situations you might encounter when georeferencing an image. Here's the process if the image has control points marked on it. the control points are labeled with their x,y coordinates, and the coordinates are in the same coordinate system as the existing dataset. Add the image to the map, along with the dataset you'll be adding features to. If you zoom to the image (right-click it in the table of contents and click Zoom To Layer), you won't see the existing features, since the image is still in page units, and the features are m map units. 190 3 • Data Compilation and Editing Now zoom to the location on the existing parcels layer corresponding to the location of the image To add links and transform the image, you'll use the Georeferencing toolbar. Click the View menu, point to Toolbars, and click Georeferencing. iw—. jflva ~3pi~^ • / ■ a- •»• J.- Use Fit To Display to show the image in roughly the same location as the existing features—that will make it easier to work as you add links. 191 Using ArcGIS Desktop a s* as 3P, Control Pt 4 X = 711900 Y = 942430 I 1-C'icJr here 1» K r— i«* w*- a* □ efts* B> ■*!'■*■ JiZ#-»a«f > * . *] 3 - - ft .Adc* Cortfmf Points Using a magnifier window makes it easier to see the control points on the image (see 'Creating and modifying features')- Click the Add Control Points button. To add a link, click the control point on the image.... ....then right-click to enter the x and y coordinates for that control point. The image adjusts as you add links. To review the links you've created, click the View Link Table button. You can remove errant links by selecting them in the table and clicking the X button. When you're satisfied with the registration of the image to the existing features, click Update Georeferencing on the Georeferencing drop-down menu. 3 • Data Compilation and Editing You can then draw the new features by tracing over the image using any of the editing tools descnbed eadienn the chapter If the coordinates on the image are in a different coordinate system than the existing dataset, you'd create a new point feature class or shapefile in that coordinate system, create the control points as point features in this new dataset at the x.y locations indicated on the image, and then project the dataset to the coordinate system you're using. You'd then be able to link the control points on the image to the control point feature class in the correct coordinate system and transform the image. You'd click the control point on the image, as shown below, then—rather than entering the x.y coordinates to create the link—you'd click the corresponding control point feature. To enter links using a layer of control points, after clicking the Enter Control Points button on the Georeferencing toolbar, click the control point marked on the image, then click the corresponding point feature on the control points layer. -then click here In some cases there may be control points on the image, but no coordinates indicated. Hopefully, the control points will be at recognizable features, such as street intersections, or the peak of a hill. You'd then find the corresponding features in your dataset, create the links, and transform the image. If there are no control points on the image, you'll have to try to identify features on the image that you can link to corresponding features on a dataset you have. Streets and street intersections—if any—are good candidates. 192 193 Using ArcGIS Desktop Digitizing from a printed map To digitize directly from a printed map. you use a digitizing table connected to your computer. ArcGIS converts positions on the table surface into digital x.y coordinates as you trace them with a handheld puck (a pen or mouse-like device). As with creating features interactively or on-screen digitizing, you use a digitizing table within an edit session. With a digitizing table installed, the Digitizer tab is available on the Editing Options dialog box. The digitizing puck is initially in mouse mode—you can click menus and buttons on the computer screen. You can still use a mouse connected to your computer as you normally would, as well—having the digitizing table in mouse mode just allows you to access the ArcMap interface using the digitizing puck. Set the Enabled option to put the digitizing table in "digitize"" mode. The first step is to register the map—which is in page units on the digitizing table—to geographic space. Your map must have control points drawn on it for which you know the x.y coordinates. To register the map. you enter the point on the digitizing tablet, then type in the x.y coordinates for that point. f ~3 zl X! * * M fJO«™ ] t«jdsfl> 1 V- 1 "tI MM3E The Enabt&d option r EnaW 3 F° 3 * ' I WS Ejk» JOUST" When you install a digitizing table, the Digitizer tab appears on the Editing Options dialog box. Check the Enabled box to set the digitizer to 'digitize" mode. To register a map. click a control point on the map—(he location (in page units) will appear. Type the corresponding geographic x,y coordinate values in the X Map and Y Map columns; an RMS error for that control point will appear. As you add points, a cumulative RMS error is displayed After you've entered the control points and their coordinates. ArcMap displays an error report. The error report includes two error calculations: a point-by-point error and a root mean square (RMS) error. The point-by-point error represents the distance deviation between the transformation of each input control point and the corresponding point in map coordinates. The RMS error is an average of those deviations. ArcMap reports the point-by-point error in current map units. The RMS error is reported in both current map units and digitizer inches. If the RMS error is loo high, you can re-enter the appropriate control points. To maintain highly accurate data, your RMS error should be less than 0.004 digitizer units (often inches or centimeters) or the equivalent scaled distance in map units—the ground units in which the coordinates are stored. For less accurate data, the value can be as high as 0.008 digitizer units. 3 • Data Compilation and Editing To start digitizing features, select the Sketch tool on the Editor toolbar. Since you*re creating the features by tracing, the other options for entering vertices are unavailable (such as creating a curve or entering a direction and distance). You can. however, use snapping to have vertices you enter snap to existing features displayed on the screen. To digitize, WW trace over the printed map, by either clicking points on the puck (point mode) or by simply moving the puck over the feature you want to digitize—without clicking—and having ArcMap automatically add vertices {stream mode). The stream tolerance specifies the distance interval between vertices added in stream mode. You can also specify that points be grouped when added—when you undo or delete the previous entry, the whole group of points will be deleted (not just the last one entered). That way you don't have to delete the points individually to erase a line segment. ~2 iliMa I r.Tifnl mm.ii| "i -liil dl» i • ■ To use the digitizer in stream mode, first click the General tab on the Editing Options dialog box. and enter a stream tolerance (in map units) and the number of points to group. Then, with the Sketch tool selected, rightelick anywhere on the map. and click Streaming on the context menu. You can then use the F8 key to switch between point and stream mode. 194 195 Using ArcGfS Desktop Creating features using vectorization Vectorization is another method of digitizing features. The ArcScan for ArcGIS extension enables you to automatically create features from a scanned image you've added to your map. As with digitizing, you create features within an edit session. You need a dataset (feature class or shapefile) to create features within. It can be a new. empty dataset. or a dataset with existing features that you're adding more features to. 7b open the ArcScan toolbar, click the View menu, point to Toolbars, and click ArcScan. In order to use the ArcScan tools, you need to have the ArcScan extension enabled (click Extensions on the Toots menu). You also need to be in an edit session. You can vectorize the image either by tracing or by using automatic "batch" vectorization. You'd trace if the image is of poorer quality or has lots of text or extraneous pixels that might end up as features you don't want. If your image is fairly clean, you can remove any unwanted pixels (either by painting over them or by selecting and deleting) and then create the vector lines (or polygons) using automatic vectorization. 3 • Data Compilation and Editing With either method, the first step is to set the snapping environment to make sure the lines you create snap to the pixels in the image. When using ArcScan. snapping is specified in two places—on the Raster Snapping Options dialog box. and on the Snapping Environment dialog box. First set the snapping tolerance (in pixels) on the Raster Snapping Options dialog box (click the button on the ArcScan toolbar). 196 Then set raster snapping on the Snapping Environment dialog box. 197 Using ArcGIS Desktop To trace over the lines on the image, use the Trace tool on the ArcScan toolbar. The Editor toolbar must also be displayed, and an edit session must be open—click Start Editing on the Editor toolbar, and select the Target dataset to create the features within. d--™i* HnalM ßhaa-ss 201 Using ArcGIS Desktop To select several features and display them in the box simultaneously, press the Shift key while selecting, or drag a box using the Edit tool. When you click a feature in the list, it flashes red on the map. To select several features and add them to the dialog box. press the Shift key while selecting. Click a feature in the list (left panel} to view and edit its attributes. To assign a value to all the selected features, click the layer name at the top of the list. You can then click the Value field next to the attribute and enter the value—all the features in the list will be assigned this value. •jy«i»px ~3 J *■ >o v 9 > .-h---- s ~3 . pi t □m in j-«j , X* *■ 9H • m Prat. l*dm i m we* To assrgn tfie same attribute value to all the selected features, click the layer name. The values column is blank, but when you click next to an attribute, you can enter the value. 1F1 I 3 ■ Data Compilation and Editing Use the Fields tab on the Layer Properties dialog box to set the Primary Display Field—features are listed by the values in that field (you'll usually use a name or unique identifier). Right-click a feature in the list to flash it on the map or zoom to it. Use the Fields tab on the Layer Properties dialog box to specify which attribute to use to identify features in the Attributes dialog box. Select the attribute values that wilt appear in the list using the Primary Display Field drop-down list. ~3 il *-»n w He*»*«-3 ■vans ~ n|UW|MltflMr.| mMin -fUSt QASS UrUi When you select a feature in the list, it flashes on the map. You can also right-click to highlight a feature, or zoom to it. If you're adding attribute values for newly created features, the values for each field are set to , except for fields for which default values have been defined or fields calculated and maintained by ArcGIS (shown in gray in the dialog box). Type over the to enter a valid value. Use the drop-down menus to assign values to fields for which domains or subtypes have been defined. □ *y • l *r x ^ - . jTTS- ~3 :t *> • n w ~3 »C Select and type over a value setting to change the value. Domain values and subtypes are available from drop-down menus when you click in the Value column for that attribute. 203 Using ArcGIS Desktop Using an attribute table to add or edit attributes You can also assign values using the attribute table for a layer (to open the table, right-click the layer in the table of contents and click Open Attribute Table). When viewing a table outside an edit session, the column headings have a gray background. If the table is open during an edit session, the fields available for editing have a white background for the column heading, while the fields maintained by ArcGIS and which can't be edited maintain a gray column heading. Also, the editing icon (pencil) appears at the bottom of the table, next to the Options button, to indicate an edit session is open. To edit a value, simply click the value you want to change in the table and type over it. To open an attribute table, right^lick the layer in the table of contents and click Open Attribute Table- Type over a value in the table to change it. __^ Right-click the gray box at the beginning of a row to highlight that feature on the map, or to zoom or pan to it. An advantage of using the attribute table is that you can calculate values for multiple features at one time—either for all features, or a selected set. (The Show Selected button at the bottom of the table window displays only the selected features, if any. making it easier to see the features you're calculating values for.) To do this, you create an expression using a combination of constants, mathematical or logical operators, and values in other fields in the table. For example, you might calculate the value per square foot of parcels by dividing the assessed value of each by its area. Right-click the field column heading and use the Field Calculator to create the expression and calculate the values (the value you're calculating can be of any type—numeric, text, and so on). IB u -j i * « X M ~3 J. »»n «7 H3 .■<=>■ a To calculate values for all features (or a selected set) for a field, right-click the column heading for the field and open the Field Calculator. Complete the expression in the lower box. Iii 204 3 u-. 3 • Data Compilation and Editing You can edit values in the attribute table outside an edit session, but only by using the Field Calculator—not by entering individual values in a column. When you calculate values outside an edit session you'll get a warning message telling von the Undo button is unavailable. r Dort «*•»**, When you use the Field Calculator outside of an edit session, you'll receive this warning message. If you want to undo your edits, you'll need to recalculate new values, or delete the Held and add it again. Use the Fields tab on the Layer Properties dialog box to control which fields appear in the table (this is useful if the table contains many fields, and you're only editing one or a few of them). \*tm If llW. i J. After setting the visible fields, only the specified fields are displayed. To open the Layer Properties dialog box, right-click a layer in the table of contents, and click Properties. On the Fields tab. select the fields you want to be visible in the table. You can also hide a field by right-clicking the column heading and clicking Turn Field Off. To show the field again, check it on the Layer Properties dialog box. or click Options on the table and click Turn All Fields On (this will, of course, show all hidden fields). Hide a field from the table by right-clicking the column heading and clicking Turn Field Off. Editing attributes for datasets having table relationships If you're editing an attribute table that has a related table (that is, a relationship class has been defined—see "Building relationships between features and tables' in Chapter 2). you can access and edit the records in the related table from the original table. For example, if you have a table of landowners that is related to a parcel feature class, you can select a parcel feature, use the relationship class to find the owner of that parcel, then edit the attributes in the owner table. You can edit a related table using either the Attributes dialog box or the attribute table. Some relationship classes have rules that control how features can be related. After you edit related geodatabase features or tables that have relationship rules, you can validate your edits to check that the related objects still conform to the relationship rules (see "Checking your data for errors' in this chapter). 205 Using ArcGIS Desktop 3 • Data Compilation and Editing x» Im» ! • ZM OBXCnp a» • »15 '• am- SSSSi »»» * ^ ■ tm «1 • Mt oucm •«c»tnr.jp MM M« f>K»«e mm «H> pair r^^B^^BaM • an Om*^> 0M KIM * ITU * ITS* * BBS |tQIMw*< Tb ecW a related table using the Attributes dialog box, click the plus sign next to a feature to list any related tables. When you click the related table for a feature, the related record is displayed. You can edit the values as you would for the feature attribute table. To open a related table when editing using the table window, click Options, point to Related Tables, and click the name of the related table you want to edit. The related table opens: you can edit the values as you would in the feature attribute table—by entering a value in a column, or right-clicking a column heading and using the Field Calculator Adding fields to a table If you need to add a field to the table, use the Options menu. You cannot do this while in an edit session save your edits, stop editing, add the field, and then restart the edit session). See also 'Adding fields and attribute values* in Chapter 5. (if necessary, calculating To add a field to a table, click Options, and click Add Field. Define the field properties in the Add Field dialog box. Creating and editing annotation ArcGIS provides several options for displaying text on a map to describe particular features or add general information to the map. One simple option is to use map labels which are created from feature attribute values and are placed automatically (see 'Labeling features" in Chapter 4). Another option is to create annotation. With annotation, the position, text string, and display properties of text can all be edited. Using annotation allows you to select and position individual pieces of text. This provides flexibility in the appearance and placement of your map text. Annotation can be stored with a specific map ("map document annotation") or stored in a geodatabase. enabling the same map text to be placed on different maps ("geodatabase annotation"). Editing map document annotation Map document annotation can be quickly created by converting labels on your map (see 'Labeling features' in Chapter 4). It is stored in the map in which it was created. You edit map annotation using the tools on the Draw toolbar, as you would other graphics (you can use these same tools to create map document annotation). To edit an individual annotation, select it using the Select Elements tool. You can then drag it to a new position or rotate it using the Rotate tool. Press the Delete key to delete the annotation, or right-click and click Delete. Walnut "3f~~3 . / i A- J* Select map annotation using the Select Elements tool. Selecí Elem&nts □ £ a « i«ax n « fT5 * * - -I 3 - - ~3 4. *.%u vt - c H ^ Drag selected map annotation to reposition it. Use the Rotate tool to rotate it around its center point. 206 207 Using ArcGIS Desktop 3 • Data Compilation and Editing To change the font, size, or color of the annotation, use the tools on the Draw toolbar. Text font Text size Taxi cotor Right-clicking displays additional options. .'ill « »Bx ' • *F» 3 •_:»»•■: »> 0 ♦ ■ ,J -3IT-3 ■ ' I A- »- -i.- Right-click a selected annotation to display editing options. Creating and editing geodatabase annotation Geodatabase annotation is stored as a feature class in a geodatabase. Because of this, it can be added to different maps and accessed by anyone in your organization who has access to the geodatabase. Geodatabase annotation also has a wider range of editing options than does map annotation. There are two types of geodatabase annotation—standard and feature linked. Standard annotation is independent of features in the geodatabase. For example, you might have a piece of standard annotation that labels a mountain range or a neighborhood in a city—the annotation simply marks the general area on the map. Feature-linked annotation is associated with the feature it is describing. The text reflects the value of a field or fields from the feature to which it's linked—if an attribute value is updated, the linked annotation is also updated. You might use feature-linked annotation to identify particular features like streets, buildings, or rivers. If you move. copy, or delete a feature, the annotation is moved, copied, or deleted with it. In addition, with feature-linked annotation, as you create new features annotation \ be created automatically. A quick way to create geodatabase annotation is to convert existing labels on a map in ArcMap. the same way you would when creating map document annotation. By default, the annotation is feature linked (since you're creating it from labels associated with the features) but you can uncheck the box to make it standard annotation. When you create geodatabase annotation you specify a reference scale. This is the map scale at which the annotation will appear at its assigned font size (the size will increase when you zoom in and decrease when you zoom out on the map). On the dialog box. select the option to store annotation in a database. By default, annotation is feature finked. The annotation feature class will be created in the same geodatabase or feature dataset as the feature class you're creating annotation from. To create geodatabase annotation from map labels, right-click the layer you want to create annotation for and click Convert Labels to Annotation. You'll first want to make sure the labels are the size you want for the scale they're displayed at (this becomes the reference scale). The annotation is added as a new layer to the map {it initially looks the same as the labels it was created from, but you can now select and edit individual text). Another way of creating geodatabase annotation is to create an empty feature class, in ArcCatalog, and then create annotation w ithin the feature class using ArcMap. You'd use this method when creating a structure for your geodatabase as pan of the geodatabase design process as described in Chapter 2. Creating an annotation feature class is described on the next page. 208 209 Using ArcGIS Desktop To create an empty annotation feature ciass in ArcCatalog. right-click a feature dataset (as shown here) or a geodatabase, point to New. and click Feature Class. The new annotation feature class (Street_anno) appears in the Catalog tree, in the feature dataset it was created in. At this point, there are no annotation features—you need to edit the feature class in ArcMap to add them. 210 -aXS3-fi±j I- Enter a name and (optionally) an alias for the feature class. From the drop-down list, specify the type as Annotation Features. Hj Specify the reference scale for the annotation You can specify more than one class for the annotation—you might create one class for major roads and another for local streets if the annotation symbols will be different tor each class. You also specify the symbol for each class here. The required fields are automatically created, so just click Finish to create the annotation feature class. 3 • Data Compilation and Editing Alter you specify the feature class type as annotation, you're given the option of making it feature linked, and specifying the feature class to link it to. If you do create feature-linked annotation, you'll be given additional options for specifying editing behavior and annotation placement. If you create annotation at the geodatabase level you'll be presented with additional panels prompting you to specify the coordinate system for the annotation, and the x.y tolerance. And if you're creating annotation in a file or ArcSDE geodatabase, you'll be given the option of entering a configuration keyword. See "Creating feature classes and tables1 in Chapter 2 for more on these settings. You edit geodatabase annotation in an edit session in ArcMap (see "Starting and managing an edit session' earlier in this chapter). Once you've added the annotation feature class to your map, open the Editor toolbar and start the edit session. You can use the Editor toolbar to perform some basic editing on existing annotation. Use the Edit tool to select the annotation to edit. You can then drag to move it. or use the Rotate tool to rotate it. As with any edit session, the Undo and Redo buttons are active. 1 jí y a x »*■ x i - e> frnš- \ V • ' ■ A.- »■ J.-i- Use the Edit tool on the Editor toolbar to select and move geodatabase annotation. Use the Rotate tool on the toolbar to rotate selected annotation around its center point. Right-click the annotation to display more options, including Copy and Delete. Click the Attributes option (or click the Attributes button on the toolbar) to change the appearance of the annotation, or to change the text (by typing in the box). Dil« II ~3 -J. Amn ir "3 oi o a Right-click selected annotation to display more options. Click the Attributes option or the Attributes button on the toolbar to change the annotation text and symbol. JÍ |i5«l r*=-315—3 mi "fjlal "3FT3 ■ / ■ A- * - >L~ -■ 211 Using ArcGIS Desktop For additional editing options, or to create new annotation, open the Annotation toolbar from the Editor drop-down list. Point to More Editing Tools, and click Annotation. Open the Annotation toolbar by clicking More Editing Tools, then Annotation on the Editor drop-down list. When you select annotation using the Edit Annotation tool on the Annotation toolbar, a blue box (known as the bounding box) appears around the annotation. The box provides several options for interactively editing the annotation. Click and drag the lower left or lower right comer of the box to rotate the annotation (the annotation pivots around the opposite corner). □ «cm ~3 -Jt v äW-s)- The bounding box around the annotation lets you rotate the text—dick either small arc that appears in the lower left and right comers and drag to rotate the box. When you release the mouse button the text is rotated. Edit Annotation tool 212 3 • Data Compilation and Editing Click ihe red triangle at the top of the box and drag the cursor up or down to interactively increase or decrease the text iiK. Click the crosshair in the center of the box and drag the cursor to move the text. SB • e • - * □ • ~3 - n o d When you select the red triangle in the box, the cursor changes to a vertical line with arrowheads. Drag the cursor up to increase the text size: drag it down to decrease the text size. ~3 l--b, f--L...t«B TFT3 ■ f ■ A- . Right-click to display more options, including changing the curvature of the annotation—you can change it from straight (that is. straight-line at any angle) to horizontal or curved, for example. Right-click selected annotation to display a context menu with additional options. The Curvature setting lets you change the annotation type 213 Using ArcGIS Desktop 3 • Data Compilation and Editing To create new annotation, first make sure the Target on the Editor toolbar is set to the layer to receive the annotation. Then select the Construction type from the drop-down list on the Annotation toolbar. ~3 J *.»o « *\ To create annotation, first ».*«- * □ • a • [** choose the annotation Construction type from the drop-down list. Type the annotation text in the Text box. then click the Sketch tool on the Editor toolbar and place the annotation on the map. Each time you click, annotation is placed on the map (so you can place the same annotation text in multiple locations). To stop placing annotation, click any tool on the Editor toolbar or on the Annotation toolbar. —3 m\ Type the text for the annotation in the Text box. then select the Sketch tool. Use the cursor to place the annotation in the correct location—the text is previewed as you drag it For Horizontal annotation, the text is placed when you click the cursor. You can continue placing the same annotation text in other locations. - ./ba--- For Horizontal, Straight, and Leader Line you can also click the appropriate button at the left end of the Annotation toolbar to place the annotation. Each type of construction works slightly differently. When placing Straight annotation, click to place the center point, then drag around the center point to the desired angle, and click again to place the annotation. Curved annotation lets you enter the vertices of a line along which the annotation will be placed. For the Follow Feature construction, click a feature the annotation will be parallel to, then click again to locate the annotation along that feature. For Leader Line, click the location of the leader line end point, then drag to place the annotation—the leader line stretches to the annotation as you drag it. ~3 J. v To place Leader Line annotation, click near the feature the annotation is for. then drag the text to the desired location—the leader line stretches as you drag the text. Click to place the annotation text. Type the text here 214 215 Using ArcGIS Desktop The text symbol used for the annotation is one of the symbols specified when you created the annotation feature class. Right-click an annotation to change the text symbol or leader line for that specific annotation. These symbols are stored in what's known as the annotation symbol collection. ~3 j. *v To modify the symbol for a particular piece of annotation, select the annotation using the Edit tool on the Editor toolbar, nghl-click. and click Attributes. Choose another symbol from the symbol collection using the drop-down list in the Attributes dialog box or use the buttons to change the font, size, and so on. Click the Leader button to modify the leader line. ~~3 B □ - a - .«. ~3F~3 ■ * h A- 1*^-"3 Ii 3 ■d 111! "J A-^faoaoci ^1 I-* I Si-* I Click the Symbol button on the Editor dialog box to open the Symbol Selector and specify the leader line color and thickness. -I j I —3 I Pom fttft |nrjm Ma [orjrjrjc ^ Use the Editor box to set the gap between the leader tine and the text, the leader line type, and other options. You set the symbol for leader line annotation—along with other properties of the annotation-the Attributes dialog box (existing leader line annotation won't change). sn the Annotation tab of 216 3' Data Compilation and Editing ~H ii *- • □ v * € CWcfc Options on the Editor drop-down list to specify the annotation settings, including the leader line symbol to be used for annotation you're adding. O/i (he Annotation tab, click the Leader button to open the Editor dialog box and set the leader line properties for leader line annotation you add, 6—m\ D^mw\ tula I Vmmwwn[ Unfa . Illn *" —- -|| i [ ™--■■---T~r1 -Til if _■ ""H 1 _s-±J _I rO *n c\A fr r- .J rT lA fö555~ä] I» [5ööS~jj] 3 K| «||ST3 ] IK I Qgg You can add new annotation symbols to the symbol collection at any time in ArcCatalog. Right-click the annotation feature class in the Catalog tree and click Properties. Then click New on the Annotation tab. MS [rum J_I .iui - m 17=-3 v- |i-3 J — I Use the Symbo/ Selector to choose anew text symbol to add to the annotation symbol collection. 217 Using ArcGIS Desktop Creating and editing dimensions 3 • Data Compilation and Editing Dimension features are a specialized type of geodatabase annotation for showing lengths or distances on a map. A dimension may indicate the length of a side of a building or land parcel, or it may indicate the distance between two features, such as a fire hydrant and the corner of a building. Dimension features are stored in dimension feature classes in a geodatabase. You need to create a dimension feature class before creating the dimension features themselves. • ft To create an empty dimension feature class in ArcCatalog, right-click a feature dataset or geodatabase. point to New. and click Feature Class. If you select the option to create a style, click the New Style button on the wizard panel to open the Dimension Style Properties dialog box Specify the symbols and spacing for the dimension and extension lines, the dimension text symbol, and so on. Enter a name and (optionally) an alias for the feature class. From the drop-down list, specify the type as Dimension Features. Specify the reference scale for the dimensions. This is the map scale at which the dimensions will appear at their assigned font size (the size will increase when you zoom in and decrease when you zoom out on the map). Also specify whether to accept the default style, create one. or import one from an existing dimensions feature class. If you're creating a Tile orArcSDE geodatabase. at this point you'U be given the option of entering a configuration keyword (see 'Creating feature classes and tables' in Chapter 2). The required fields are automatically created, so just click Finish to create the dimensions feature class. It is added as a new feature class in the feature dataset you createdM in. (You can also create dimension feature classes at the geodatabase level.) Dimension features arc added to a dimension feature class in ArcMap. within an edit session. First, add the dimensions feature class to your map, along with the features for which you're adding dimensions (the parcels, streets, buildings, or other features). Then open the Editor toolbar, and start an edit session. Specify the Task as Create New Feature, and specify the Target layer as the dimensions feature class; you'll also want to set the snapping environment to the vertices of the features you're dimensioning. Then open the Dimensioning toolbar which contains tools for creating dimension features. j i 4 To open the Dimensioning toolbar, click the Editor drop-down menu, point to More Editing Tools, and click Dimensioning. The options on the toolbar are active only during an edit session. Click Snapping on the Editor drop-down menu to set the snapping environment. Check the box under Vertex for the layer you're creating dimensions for or other layers you want to snap to. Use the Construction drop-down list on the Dimensioning toolbar to specify the dimension type. Specify the type of dimension from the Construction dropdown list. 218 219 Using ArcGIS Desktop 3 • Data Compilation and Editing The dimension features are based on points that you input with the Sketch tool. An "aligned" dimension, for example, requires three points: the start point, the end point, and an offset point. Select the Sketch tool on the Editor toolbar, then enter the points on the map to create the dimension. As you move the mouse, you will see that the new dimension dynamically draws itself with the cursor location as the end dimension point. When you click the final point, the dimension position and text are fixed. To create an aligned dimension feature, click the vertex corresponding to the beginning of the dimension line; click the vertex corresponding to the end of the line; then move the cursor perpendicular to the line to set an offset and click to finish the dimension feature. You can create aligned, simple aligned, horizontal linear, vertical linear, or rotated linear dimension features. 9.5' vi* Aligned Honzontat linear Vertical linear There are several tools on the toolbar that allow you to create new dimension features from a selected feature (these are available from the Autodimension palette). You select the dimension type, then select the feature—the dimension is created automatically. If more than one style is defined for the dimension feature class, select the one to use from the drop-down menu on the Dimensioning toolbar. To override the current dimension style for a particular dimension feature, right-click the feature and click Attributes. The dialog box lets you change the dimension style. i 4 ^ •' ~3P1~3 ■ / o A To override the default style for a selected dimension feature, right-click the feature and click Attributes. Then change the settings in the Attributes dialog box. ■ um» [i* 3 [5355 3 You can add more styles at any time in ArcCatalog (except when the dimensions are being edited in an edit session in ArcMap). Right-click the dimension feature class in the Catalog tree, and click Properties. On the Dimensions tab. click New to open the Dimension Style Properties dialog box, and define the properties of the new style. To create a new dimension style for a dimension feature class, right-click the feature class in the Catalog tree, click Properties, and click the Dimensions tab. Click New. After entering a name for the style, the Dimension Style Properties dialog box will open, C 220 221 Using ArcGIS Desktop 3 • Data Compilation and Editing Editing routes and geometric networks Routes and geometric networks are collections of line features and junctions, or intersections, used to represent transportation and utility networks. You create both types of datasets using ArcCatalog (see 'Adding specialized datascts to a geodatabase" in Chapter 2). ArcMap contains tools for interactively editing the datasets to add or delete features. Editing a route dataset Routes are collections of linear features built from existing features such as roads or pipelines. They're often used to manage subsections of an existing line dataset—for example, to indicate different pavement conditions along stretches of a highway. They are also used to assign geographic locations to events stored in a table (see 'Assigning locations using street addresses or routes' earlier in this chapter). You can modify an existing route dataset—or add features to an empty dataset you created in ArcCatalog—using tools in ArcMap. Routes are edited within an edit session, using tools on the Editor toolbar and the Route Editing toolbar. First, add the route dataset to your map. Then open the Editor toolbar and click Start Editing on the Editor drop-down menu. Set the Target layer to be the route dataset. You can use the Edit tool to select a route, then right-click to delete the route or click Attributes to modify its attributes (such as the route ID). If you're adding features to the route (as opposed to merely deleting them or modifying their properties) you'll want to also add the dataset containing the base features (such as a streets dataset). Set the Task to Create New Feature. Then open the Route Editing toolbar—point to More Editing Tools on the Editor drop-down menu, and click Route Editing. To open the Route Editing toolbar, click the Editor dropdown menu, point to More Editing Tools, and dick Route Editing. The options on the toolbar are active only dunng an edit session. To create a new route, select the base features that will comprise the route using the Edit tool on the Editor toolbar. Press and hold the Shift key to select multiple features. Once you've selected all the features to include in the route, click the Make Route button on the Route Editing toolbar. t** ■ » y m ibex t * 1 :'. ~ ü 3 ' r—3 . • a 3 <~<- ► —zj tw|«..» n ;:,:r 1 Ml SB kBsm d ™.v 1 J '[."■■Mi-i'iti ii i 1 J runt mri.niuM, ^ lu'ftn.iF.n d i 225 Using ArcGIS Desktop Editing a geometric network Geometric networks are used to represent utility networks such as electrical networks or w ater systems. They are built in ArcCatalog. using existing features—for example, transmission lines, capacitors, transformers, and so on, for an electrical network (see 'Adding specialized datasets to a geodatabase' in Chapter 2). A defining characteristic of a geometric network is that it stores and maintains the connectivity between the various features in the network. Geometric networks are edited in an edit session in ArcMap. Add the network to your map (when you do, all the feature classes that comprise the network are added to the map). You can delete features or modify the attributes for a feature in the network as you would any other feature. Select the feature using the Edit tool on the Editor toolbar. Right-click to delete or copy it (keeping in mind that deleting a feature may impact the connectivity of the network). Click Attributes to modify its attribute values. Because the connectivity between features in the network is inherent, when you move a feature, the features to which it is connected move with it to maintain the connectivity. 3 • Data Compilation and Editing Sr g» M >Ma> W^. M ^ y * 1«BK - ™ # F ~3 J «.»o « a -. * » o a e> m— a" M ä 1 To edit a geometric network, open the Editor toolbar, and click Start Editing on the Editor drop-down menu. Use the Edit tool on the toolbar to select the feature to work with. When you drag to move a feature, the junction at which the feature connects to other features moves with it, and the connected features stretch accordingly. There may be cases where you need to move a feature without changing the position of features it's connected to (for example, to move the position of a transmission line without moving the position of the pole it s connected to). To do this, you need to first disconnect the feature. Open the Geometric Network Editing toolbar from the Editor drop-down menu. Then select the feature to disconnect—using the Edit tool on the Editor toolbar—and click the Disconnect button. <• ;I fßmtUn leak -r**- 0* ~~3 u *%%av To disconnect a feature from the network, open the Geometric Network Editing toolbar (click the Editor drop-down menu and point to More Editing Tools). QtfHS I ** B X * * i ....-WW ~3 J. v zS y ft n q • 1 With the feature selected, click the Disconnect button on the toolbar. 226 227 Using ArcGIS Desktop 3 • Data Compilation and Editing Now when you move the feature, the connected features stay put. To reconnect the feature to the network, snap an end to a feature on the network, and click the Connect button on the toolbar. □ a a ifeix m • *> h zl :,* a • 1 ». * - a Wften you move (he disconnected feature, it floats free of the network. To reconnect a feature to the network (or connect a new feature), snap the feature to an existing network edge or junction, and click the Connect button on the toolbar When adding a feature to a geometric network, you'll want to set the snapping environment so that all layers in the network have snapping on. That will ensure new features snap to existing ones, thus maintaining network connectivity. 228 When adding features to a geometric network, set snapping on for the network layers. Point features should have Vertex checked; line features should have Vertex and End checked (as well as Edge, if required). 229 Using ArcGIS Desktop Checking your data for errors ArcGIS Desktop contains several tools to help you check for errors in your geodatabase that may have been introduced during editing or when importing data. These validation tools work within an edit session in ArcMap (see 'Starting and managing an edit session' earlier in this chapter for a discussion of starting an edit session). The Validate Features tool checks for invalid values for subtypes or attribute domains, as well as invalid relationship classes and broken network connectivity. The Topology toolbar lets you check and verify any topology rules you've established for specific datasets. Validating attribute values The Validate Features tool on the Editor toolbar checks the values of domains and subtypes to make sure they're valid (see 'Ensuring attribute data integrity' in Chapter 2 for a discussion of creating domains and subtypes). When editing subtypes and coded value domains using the Attributes dialog box. a drop-down menu lets you select from a list of valid values to ensure that acceptable values are entered (see 'Adding and editing attribute data" earlier in this chapter). However, it may be the case that there are attribute values in a field that pre-date the creation of the coded value domain or subtype. Also, values entered using the field calculator in the table window are not restricted to those defined in the coded value domain or subtype, so errors may creep in if values are entered using this method. For range domains, the values that can be entered—using either the Attributes dialog box or the field calculator in the table window—are not restricted when you enter them. so. again, errors may occur. The Validate Features tool finds any invalid domain or subtype values that occur in the table, for the selected fcature(s). and displays a message. After starting an edit session, use the Edit tool to select the feanire(s) to be validated. Then click the Editor drop-down menu and click Validate Features. If a single feature is selected, the message indicates the nature of the problem. To check for invalid subtypes or attribute domain values, open an edit session and use the Edit tool to select the feature to check. Then select Validate Features on the Editor drop-down menu. A message is displayed indicating the error. If there are no errors, the message indicates that all features are valid. Right-click the feature to open its attribute dialog box and correct the value. 3 • Data Compilation and Editing Right-click the selected feature and click Attributes to correct the invalid value. 1 un TOI ~ - ■"- -Hi. «** -4M* •ewcro .2.1--. ■ If more than one feature is selected, the message tells you how many features have invalid values; only those features remain selected. Select one of these features and run Validate Features again to get an explanation of why the feature is invalid (or just open the Attributes dialog box for the feature and see for yourself). -Bill 3 .1 (=i d a You can select multiple features before running Validate Features. The message will indicate how many features have invalid values. Features with no errors are unselected. leaving selected only the features having invalid values. 230 231 Using ArcGIS Desktop To open the Attributes dialog box, click the Attributes button on the toolbar, or right-click one of the selected features and click Attributes. The selected features are listed in the left panel; click a feature in the list to display and edit its attributes. HIT TF|t= ±_ t— Ö LT ■ni in I "no " «-> 1 1 ro 1 w - tn» FS 14» PDUJCTW Ufr "I la J— .---irmi. »«•_*" Setect a feature from the list in the left panel of the Attributes dialog box to display the feature's attributes and correct any errors. Validate Features checks for the different types of errors sequentially, so if a feature has errors of more than one type it will generate a message if you run it again. For example, if a feature has an invalid subtype and an invalid domain value, it will generate an error when the invalid subtype is encountered. If you fix the error and re-run Validate Features, a message will be generated when the invalid domain value is encountered. Validating relationship classes and network connectivity Validate Features will check to make sure any relationship class rules you've set up in your geodatabase are not broken. For example, in an electric network, there may be a relationship class between substations and feeders, with a rule that a substation cannot have more than two feeders. Validate Features will check to ensure there are no violations of the rule (a substation has no more than two feeders associated with it). Select the feature or features to validate, then click Validate Features on the Editor drop-down menu. Validate Features displays a message indicating that all features are valid, or that it has found a rule that has been broken, and the cause. In this case, the tables or features would have to be edited to modify the relationships between the features. ~3 ' ra a d ItafMttnSubÄÄmlai««» iMMt. * *MMFMt [HJttvBo; Fw»] torn l^>^i^a»*iKUanW*A»nl*m*w£l«sS* Validate Features can be used to check tor relationship class rules that have been broken. In an edit session, select the feature to validate (using the Edit tool on the Editor toolbar). Then select Validate Features on the Editor dropdown menu. In this example, four feeders are connected to a substation, when a maximum of two are allowed 3 • Data Compilation and Editing Similarly, Validate Features will evaluate connectivity for a geometric network. In an electric network, for example, a substation might be able to connect only to a primary line. If a substation is added and connected to a secondary line, running the Validate Features tool wilt reveal this, and display a message. To correct the error, the feature would have to be deleted or moved to connect to a different—primary—line. ■ ..-Us* . ■i * ' ~3 -1 iV*D Ml a * - O (km - n imaumm H t Use Validate Features to check the correct connectivity between Feature classes in a geometric network fin this example, a substation on an electrical network is connected to the wrong type of transmission line). Validating topology rules A topology is a set of rules that define the spatial relationships between features. The rules ensure, for example, that parcels don't overlap or that census tracts completely nest within counties. If you've made edits to a feature that participates in a topology, you need to validate the topology to identify any violations of the rules that have been defined for the topology. ArcMap includes tools for validating geodatabase topology. (The tools are not available for map topology. For more on geodatabase topology see 'Ensuring spatial data integrity' in Chapter 2. For more on map topology, see 'Editing connected features' in this chapter.) Topology validation occurs within an edit session in ArcMap, using the Topology toolbar. After starting an edit session, click the Editor drop-down menu, point to More Editing Tools, and click Topology. ~3 J *.an « ■ ZD Open the Topology toolbar in ArcMap to validate geodatabase topology. 232 233 Using ArcGIS Desktop If there is more than one geodatabase topology on your map, use the drop-down list to select the one you want to validate. The toolbar includes three buttons that let you validate topology—they vary only in the extent of features they will validate. You can validate feature topology w ithin a selected area on the map. within the current extent of your map, or the entire topology. When you click one of the three Validate Topology buttons, ArcMap checks the features against the topology rules in the geodatabase. Any features that violate the rules are highlighted in red on the map. After validating, use the Error Inspector to list the errors—click the button on the toolbar to open the Error Inspector window. Use the drop-down list to specify which errors to search for and list (based on the rule that's been broken), or select Errors from all rules. Then click the Search Now button on the w indow. ■ ... u = «* ~3 J. *«a v ■ ~3 Click one of the Validate Topology buttons on the toolbar to validate the selected topology. Errors are highlighted in red. In this example, there are two parcel ovedap errors, a street ovedap. a pseudo node (a vertex that connects two line segments—it may be unnecessary), and several dangles (a dangle is a vertex at the end of a line segment—some of these might be acceptable and should be marked as exceptions). — Current extent — Entire topology -3f»-3 I a- -i- -■ Click the Error inspector button on the toolbar to open the Error Inspector window. Then select the topology rules from the drop-down list. t»» 1^' I'M.' ' 3 • Data Compilation and Editing When you select an error in the list, the corresponding feature is highlighted in black on the map. You can use the Error Inspector to manage the errors—you can son the errors by any of the fields in the table so you can work with all the errors of a given type. You can also limit the errors shown in the table to errors of a given type, errors that occur in the currently visible map extent, or errors that have been marked as exceptions (that is. are acceptable, even though they violate a topology rule). □ KB* ~i at ■** OWfe «rann *urt •■Ma OSi >>*» L59S ran ZOT iiiiiii When you select an error in the Error Inspector table, the corresponding feature is highlighted on the map, in black. Right-click a row to zoom or pan to that feature. Click a column heading to sod by that column. ~~3 I*-.*- 3 -' ■ mal -3175-3 1 Click the Fix Topology Error tool on the toolbar, then right-click a selected feature on the map. You can zoom or pan to the feature, or select a fix—in this example, selecting Merge lets you pick the duplicate line to delete. 234 235 Using ArcGIS Desktop You can also use ArcCalalog to validate an entire topology. It's a good idea to do this when you first build the in ArcCatalog (see 'Ensuring spatial data integrity' in Chapter 2). Right-click the topology in the Catalog tree Validate. Errors will be displayed when you click the Preview tab. topology and click After validation, topology errors appear in ArcCatalog when you select the Preview tab. When you open a map that contains the topology, in ArcMap, any errors ArcCatalog identified will be highli; red. hted in 3 • Data Compilation and Editing Defining coordinate systems and projecting datasets The spatial reference for a feature class describes its coordinate system—for example, geographic, UTM, or State Plane—its spatial domain extent, its resolution, and its tolerance. When you're building your geodatabase, you assign the spatial reference when you create feature classes and feature datasets (see 'Creating feature classes and tables' and •Ensuring spatial data integrity' in Chapter 2). If you've received data from an outside source, the data may have a spatial reference, but u max not yet he defined in ArcGIS. Or. the datasci mn\ be in a different map projection ilian the rest of your data. ArcGIS includes tools to define coordinate systems and to project datasets to other map projections. To see if a dataset has a defined coordinate system, right-click the dataset in the Catalog tree and click Properties, then select the XY Coordinate System tab. If the coordinate system is undefined, the name will say Unknown (or Assumed Geographic if the coordinates are in degrees of latitude and longitude), and the Details box will be empty. If the spatial reference is not included in the documentation that accompanied the dataset. you'll need to contact the source and get the spatial reference information. You define a coordinate system by selecting a predefined coordinate system, importing one from another dataset, or defining the parameters for the coordinate system yourself to create a new one. You can do this in ArcCatalog (as shown on the next page) or using the Define Projection tool in ArcToolbox. * 3 >. a* *p * ft w t% DoEa Hariri To* • ! ^ Oata Caiperson - i ) Asubutad 0 M i • ül ~3m • i ■ a- »- First click the Attribute Transfer tool on the toolbar (below). Next, click the source feature, then click the target feature—the attribute values are immediately assigned to the target. jjji After transferring attributes, the target feature has the a a | same Name and Type values as the source feature. Idertiybon | TTcfHrcal-■>«> Attribute Transfer -- SAN PABLO Loctim *8- yu?9' 3.jmsj8 51sm«,, * nm (vém nr, i j Stum PoUrw NAME SAN PABLO Ihn 5 Sh«»_Lartfh «2637475 UnfMtlNM A Combining datasets into a single dataset Often, the ultimate goal of spatial adjustment and attribute transfer is to combine datasets containing the same type of feature to create a single dataset that covers your entire area of interest. For example, you may have edge matched a set of hydrology map sheets that need to be appended to create a continuous dataset. Or. you may have rubber sheeted datasets of new streets and parcels that fill a previously undeveloped area and want to drop them into the existing datasets. The Merge and Append tools in ArcToolbox are used for this. The Merge tool combines all the input datasets you specify into a single, new dataset. Append is similar, except it adds the datasets you specify to an existing dataset. In both cases, the types of features must be the same in all input datasets (all points or all lines, for example). The Merge tool, located in the General toolset (Data Management toolbox) lets you combine two or more datasets of the same type into a single dataset Specify the input datasets. and the name and location of the output dataset. 246 247 Using ArcGIS Desktop Editing multiuser and distributed geodatabases Many organizations need to maintain large geodatabases that require frequent or continuous updating, such as a city's parcel database. This often entails having several people editing the database concurrently. When you start an edit session to edit a file geodatabase or personal geodatabase, or a workspace containing shapefiles. no one else can edit that data while your edit session is active (as soon as you stop the edit session, the data is available for others to edit). The entire geodatabase or workspace is said to be -locked" during editing. An ArcSDE geodatabase. on the other hand, can be edited by several people at the same time. This is one of the main reasons for using ArcSDE. ArcSDE accesses data stored in a DBMS, such as Oracle. SQL Server. DB2. or Informix (see 'An overview of geographic data management' and 'Creating a geodatabase' in Chapter 2 for more on creating an ArcSDE geodatabase). There are several approaches to using ArcSDE to enable multiuser editing. One approach allows editors to work on the same dataset at the same time, but if an individual feature is edited by one editor, it is locked for editing—no other editors can change it. until the first editor saves the edits. Another approach allows editors to work on the same dataset and even the same features simultaneously—when the last editor saves edits, any conflicts are listed (if one editor moved a point to new location, and another editor moved the same point to a different location, for example). The conflict then needs to be reconciled before the final edits can be saved in the geodatabase. A third approach is to create a different view—or version—of the geodatabase for each editor, and let them work on their version independently. When an editor finishes edits and posts them to the main or published -geodatabase, any conflicts are listed and can be reconciled. A version is simply a view of a geodatabase, rather than a copy of the data in it—no matter how many versions of the geodatabase you create, there is still only a single copy of the geodatabase. Each version lists or displays all the datasets in the geodatabase. Versioning has a number of other advantages: you can create multiple versions of a geodatabase for sub-tasks or different phases of a project that can be edited separately from the original database, without having to create and track separate copies of the data (this is especially useful for very large geodatabases). You can create archive versions of a database to preserve a snapshot of the geodatabase at a given time. Versioning also allows you to perform editing operations that span several days or weeks—for example, adding all the parcels in a new subdivision. The editor maintains the edits in progress in a separate version and can continue to make changes and updates: when complete, the edits are posted to the published geodatabase (this process is referred to as a "long transaction"). A fourth approach is to create full copies of a geodatabase—known as replicas—which can be stored and edited separately. The replicas are then synchronized to make sure all the geodatabases are the same, and everyone is working with the same data. Using replicas may be efficient when the editing is done at multiple office locations or in the field, or when different departments or organizations are responsible for updating one portion of the geodatabase. The approach you use depends on the size and requirements of your database and the nature of the GIS work your organization does. In practice, you may end up combining some or all of these approaches. You might, for example, create replicas, and then create versions from each replica, some of which are set up for multi-user editing, and some not. The 'Geodatabases and ArcSDE' topic in the Desktop Help system includes various multiuser editing scenarios. There are two mechanisms at play when you set up an ArcSDE geodatabase for multi-user editing: there can be multiple versions of a geodatabase: and each individual dataset in a geodatabase can be registered to allow several people to edit that dataset simultaneously. • An ArcSDE geodatabase can have a single version or multiple versions. When you create an ArcSDE geodatabase, a version is created named Default, so every ArcSDE geodatabase has at least one version. This version often represents the "published" geodatabase. If necessary, you can then create additional, named versions from the Default version (or from other versions you create). Usually, you maintain and update the Default version over time by posting changes to it from other versions. You can also edit the Default version directly, just like any other version. But unlike other versions, it can't be deleted. 3 • Data Compilation and Editing . Each dataset in an ArcSDE geodatabase can be registered as "versioned," or not. Registenng a dataset as versioned allows two or more editors to edit and modify the same feature at the same time. If a dataset is not registered as versioned. several editors can still edit the dataset simultaneously, but an edited feature is locked until the editor who modified it saves the edit. With nonversioned data there are no possibilities for edit conflicts since a modified feature must be saved before another editor can modify it. Once you register a dataset as versioned. it is registered for all versions of the geodatabase you create (recall that there is only one copy of the dataset in the geodatabase, so any settings for a dataset apply across versions). You can edit versioned and nonversioned datasets in the same geodatabase. based on your requirements. If you need to edit feature classes that participate in a topology or a geometric network, you need to register the datasets as versioned in order to edit them. Registering a dataset as versioned also allows it to be enabled for archiving. The date and time of each edit, or series of edits, is stored with the dataset. which then lets you view the state of the geodatabase on any given date (see the Desktop Help for more on geodatabase archiving). Depending on the multiuser editing scenario you establish, you might implement one or both of these mechanisms. For example, you might edit the default version of the geodatabase. with all of the datasets in the geodatabase registered as versioned (you might do this if you only need to maintain a single version of the geodatabase, but need to have several people editing it). Editing an ArcSDE geodatabase using nonversioned data Your organization may not need multiple versions of a geodatabase, but rather only the ability to have several people editing the geodatabase concurrently, for occasional edits. One way to do this is to set up the geodatabase for multi-user editing using the default version with nonversioned data. With this approach, the source data is edited directly and you don't have to manage separate versions of the geodatabase. To edit using nonversioned data, first make sure the data is not registered as versioned (this is, in fact, the default when data is imported to, or created in. an ArcSDE geodatabase). In ArcCatalog. right-click the feature class or standalone table in the Catalog tree and click Properties. In the Versioning section on the General tab. make sure the dataset is listed as not currently versioned. To make sure the dataset is not registered as versioned, right-click it in the Catalog tree and click Properties. Select the General tab on the properties dialog box and check the Versioning status at the bottom of the page—ft should indicate the data is not registered as versioned. The Versioning status 248 249 Using ArcGIS Desktop When you're ready to start editing in ArcMap. display the Editing Options dialog box and uncheck the Edit a Version check box (this box is checked on by default). Then edit the data using any of the edit tools, as you would any other dataset. -JflJaJ Before starting your edit session in ArcMap, click Options on the Editor dropdown to open (fie Editing Options dialog box. On the Versioning tab. uncheck the "Edit a version' box. J. Usually this approach is used to allow people to edit different portions of a dataset at the same time (note that ArcSDE Personal Edition allows only one editor at a time, in any case). When one editor completes an operation (completing a polygon, for example), the feature locks. The feature remains locked until this editor either saves the edits or quits the edit session without saving. While the feature is locked, the other editors' edit operations on the feature are blocked, and the hourglass cursor displays in their ArcMap edit sessions. The hourglass continues to display until either the lock is released or the request for the lock times out (a setting in the underlying DBMS, if supported). Different DBMSs handle these locking issues in slightly different ways. Because of this data locking, you can edit simple data only—points, lines, polygons, annotation, and relationships. You cannot edit feature classes in a topology or geometric networks with this approach. (That's because when you edit a feature in a network or topology, not all the features in the network or topology are locked—there is the potential for other editors to edit another pan of the network or topology in a way that conflicts with your edits.) ~3 ..!.*. ^ » "TV"0*"* ; 8"" 3?— -i ~3PT3 » * ■ A- *- J. - Usmg nonversioned data for multiuser editing is useful when editors are working on different parts of the dataset. In this example, one editor is updating parcel boundaries on one section of the city (left) while another editor is updating parcel attnbutes in another part of the city (right). 250 3 • Data Compilation and Editing Editing using versioned data Using versioned data allows two or more editors to edit the same features at the same time, without feature locking. It also allows multiuser editing of topologies or geometric networks. To edit versioned data, you "register as versioned" each individual dataset that will be edited. In ArcCatalog. right-click the dataset in the Catalog tree, and click Register As Versioned. You're presented with a window that gives you the option of moving the edits to base. This option is applicable when you're editing multiple geodatabase versions (as discussed later in this section) rather than just the default version, as you are here—leave it unchecked. To edit versioned data, first—in the Catalog tree, in ArcCatalog—right-click the dataset you want to edit and click Register As Versioned. When prompted whether to use the option to move edits to base, leave the box unchecked (you 're editing the base—the default version—so this option doesn't apply in this case). When you click OK. the dataset is registered. Now when you check the Versioning status on the properties dialog box, the dataset is listed as registered as versioned (notice also that the Register As Versioned option on the context menu is now unavailable). You can confirm that the dataset is registered as versioned on the General tab of the Feature Class Properties dialog box. The Versioning status 251 Using ArcGIS Desktop When you're ready to start your edit session in ArcMap. you need to make sure the Edit a Version option is checked on the Versioning tab of the Editing Options dialog box (this is the opposite of using nonversioned data). ~2 J w ■WS. I al 3 . ' ■■ 3 3 I - Check this box J. When you're ready to start an edit session, click Options on the Editor dropdown to open the Editing Options dialog box. On the Versioning tab. check the box to Edit a version of the database. You're presented with a range of options relating to saving edits and resolving conflicts. - When you register a dataset as versioned. a couple of tables (known as delta tables) are created to store the changes to the dataset—one for additions and one for deletions. ArcGIS uses an ID (known as a State ID) for each version to keep track of which changes belong to which version. When an edit is made in a version, the change is tagged with that version's State ID when it's stored in the delta table. When the editors save their edits, the changes are posted to the geodatabase. but all the changes continue to be maintained in the delta tables. The delta tables can get quite large over time, so you need to compress the geodatabase on a regular basis (see "Maximizing the performance of your database' in Chapter 2). Two or more editors concurrently editing the same feature or features can edit without any locking during their respective edit sessions—it's as if they're editing their own version. (In fact, they are editing temporary, unnamed versions created from the Default version that are discarded at the end of the edit session.) When the editor saves his or her edits, the edits are saved in the Default version. iUJ ■ -■ E y * * ■• When editing versioned data, two editors—running two separate edit sessions—can edit the same feature simultaneously In this example, the editor running the edit session on the left has moved a point feature to the tower center of the map (blue dot). The editor on the hght has moved the same feature to a location farther to the left. They each see their own version of the dataset. if one of the editors saves the edit, when the other editor saves the edit there wilt be a conflict. 252 3 • Data Compilation and Editing In a perfect world, and with good planning and editing procedures, none of the edits made by different editors would conflict with each other. Editors working on the dataset concurrently will either work on different sets of features in different parts of the geographic area, or will work sequentially, with one editor entering more recent information; or perhaps one editor will edit the geometry of features while another will edit the attributes. However, with several editors working on the same data at the same time, there is the potential for edits made on the same feature by two (or more) editors to conflict with each other. For example, suppose two people are editing a feature class of points representing building locations, and one moves a point to one location and the other editor moves the same point to a different location. The first editor then saves edits. When the second editor saves edits, the Conflicts window will appear, indicating a conflict in the edits. Click the Conflict Display button to open a panel that lets you view the conflicting edit—the previously saved edit (the pre-reconcile edit) is shown on the left while the current edit (the one that's causing the conflict) is shown on the right. Click to display or close -(he lower parrels - HB nil CD ■1 ■ - "MM* ICUMM iFMlMMti IO*f |r-«-- 1 DMCTO ii II 11 11 WE Cwvtk>K9i Sinnig, Ha. Urni ämftot rj,„i, j,, Hm HMNIEtWI A- au HJ«_Dn it ran ~3P5~3 » / iA" *• J.- When you add data from a geodatabase with versions in ArcMap, the version you're currently connected to is displayed in the Add Data dialog box (doubie-click the geodatabase to display the datasets). You can then change to another version after adding the data. If you add data by dragging from ArcCatalog, you can add any dataset from the currently displayed version in the Catalog tree. 3 • Data Compilation and Editing To change versions, click the Source tab at the bottom of the table of contents, right-click the geodatabase, and click Change Versions. Then select the version to display. When you switch from one version to another, all datasets present n the map change to be those in the version to which you've switched. To change versions in ArcMap. first select the Source tab at the bottom of the table of contents. Then right-click the geodatabase in the table of contents, and click Change Versions. In the dialog box. select the version you want to change to. 3^ ■ / g A' *-_£-_!- The Versioning toolbar in ArcMap also lets you manage versions. On the Editor drop-down menu, click More Editing Tools, and click Versioning (you don't need to be in an active edit session to do this). You can also open the toolbar from the View menu (click Toolbars and click Versioning). 7b open the Versioning toolbar, click More Editing Tools on the Editor drop-down menu, and click Versioning. Or. click the View menu, point to Toolbars, and click Versioning (at the bottom of the list}. From the toolbar you can manage existing versions, create new ones, or change versions (if the geodatabase is currently selected on the Source tab; otherwise, this button is unavailable). 256 257 Using ArcGIS Desktop 21 _ lo~ |l— « 1 e- 1 7V?e Versioning toolbar lets you manage versions within ArcMap, as you would in ArcCatalog. You can open the Version Manager, create new versions, or open the Change Versions window. When editing a geodatabase version, you can edit a versioncd or nonversioned dataset, as described above (once a dataset is registered as versioncd. it will have that status across all geodatabase versions). When you register data as versioncd. you have the option to "move edits to base" (you'd choose to move edits to base if the updates need to be shared with other applications that access your RDBMS). If you register with the option to move edits to base, edits to the Default version save to the base tables (the tables containing the actual datasets). while edits to all other versions save to the delta tables but are moved to the base tables when you post to the default version. If you don't use this option, all edits save to the delta tables—including those made to the Default version. When you create a second (or third) version of the geodatabase. new delta tables are not created—rather all changes for all versions go into the same set of delta tables, and are tracked by version, using the State ID. When editing versioned data with multiple versions, the concepts are basically the same as when editors arc editing a single version. However with multiple versions, when editors save their edits, the edits are saved only in their version. When they've finished the edits, they reconcile them with other versions, at which point any conflicts are revealed and can be reviewed. ~~3 J. * ~3 .'« ■ o I After making edits, click the Reconcile button to see if your edits conflict with any others that have been made to the target version. You can opt to use the edit currently in the target version, or use the one in the edit version that you're working with. 3 • Data Compilation and Editing Once the edits are reconciled, the editor can post them to the target database (often the default version). Posting cannot he undone, since you are applying changes to a version you are not currently editing. This process allows editors to conduct ongoing edits over several edit sessions (so-called "long transactions") without having to save the edits in the published database until all the edits are done. Reconciling, resolving conflicts, and posting edits arc all done from the Versioning toolbar. Once any conflicting edits are reconciled, click the Post button to save the edits in the target version (usually the Default version). After posting, you can continue to make edits and then reconcile and post edits again, as necessary. Once editing is completed, the version can be deleted, if it's no longer needed—open the Version Manager, right-click the version, and click Delete. You can delete a version provided all the versions derived from it are first deleted. Only the version's owner (or the ArcSDE administrator) can delete a version. ArcToolbox also contains a number of tools for creating and managing geodatabase versions and versioned datasets. These can be used in scripts and models to automate data management tasks. The Versions toolset in the Data Management toolbox contains tools for creating and managing versioned geodatabases and datasets. 258 259 Using ArcGIS Desktop Creating geodatabase replicas for distributed editing Creating geodatabase replicas allows you to create copies of data across two or more geodatabases. make changes to the geodatabases separately, and then synchronize the changes so the geodatabases remain consistent with each other. As you might imagine, creating, synchronizing, and managing replicas is a fairly involved process that requires planning, preparation of the data, and coordination between the sites that will maintain the replicas. There are also a number of options for the type of replicas to create and methods for synchronization. The Desktop Help includes a full discussion of tasks and steps for using replicas. When you create a replica, you're creating a relationship between two geodatabases. The replica in the geodatabase from which the data originated is referred to as the "parent" replica. The replica in the geodatabase where the data is copied to is referred to as the "child" replica. Three types of replicas allow you to control whether the parent replica, the child replica, or both replicas have the ability to send and receive changes: check out/check in replicas; one way replicas; and two way replicas. A check out/check in replica allows for one-tune synchronization. Changes can only be sent from the child replica to the parent replica. Parent replicas must be ArcSDE geodatabases while child replicas can be ArcSDE. file or personal geodatabases. Check out'eheck in replication is useful for field editing where an area of the geodatabase is replicated, edited in the field, and synchronized with the parent replica. If additional field edits are required, another child replica must be created. A one way replica allows changes to be sent multiple times, but only from the parent replica to the child replica. The data on the parent is editable, but the data on the child is considered read-only (any edits to the child replica are overwritten during synchronization if they conflict with edits to the parent replica). Two way replicas allows changes to be sent multiple times from the parent replica to the child replica or from the child replica to the parent replica. If the same feature is edited in both geodatabases it is detected as a conflict when the replicas are synchronized. You can choose a reconcile policy during synchronization to define how conflicts are processed. The first step in preparing data for replication is to make sure the datasets you would like to replicate are registered as versioned (see the discussion earlier in this section). For one way and two way replication, each replicated dataset will also need to have a Global ID column. A Global ID column is a field which cannot be edited that contains a unique identifier for each row (feature) in a dataset. (Global ID fields are not necessary for check out'eheck in replication because the Object ID that each feature in a dataset has is sufficient to maintain feature identity during one-time synchronization.) To add Global IDs. use the Add Global IDs command in ArcCatalog. .. J * X -I — I— I To add Global IDs to a dataset that wilt participate in one-way or two-way replicas, right-click the dataset in the Catalog tree and click Add Global IDs. 3 • Data Compilation and Editing Replicas are created in ArcMap. using the Distributed Geodatabase toolbar. When you click the Create Replica burton, a wizard opens to lead you through the process. To create a replica, open the Distributed Geodatabase toolbar in ArcMap. Click the View menu and point to Toolbars. . P=H. Open (he Create Replica Wizard from the Distributed Geodatabase toolbar. Specify the type of replica on the first panel (Check out/Check in. one way, or two way). Then on the second and third panels, specify the name of the replica and where it will be stored, and the actions to take after the replica is created (for example, you can have the wizard create a new map containing the replica). Synchronizing replicas—after changes are made—is also done from the Distributed Geodatabase toolbar. Clicking the Synchronize Changes button opens a wizard that leads you through the process. You specify the two geodatabases to synchronize, the direction changes will be sent (if you're synchronizing a two-way replica), and how to handle edit conflicts. After the replica has been edited, open the Synchronize Changes Wizard from the toolbar to synchronize edits with the parent replica or any other replicas. The Distributed Geodatabase toolbar contains additional tools for managing replicas 260 261 Using ArcGIS Desktop Replicas can also be synchronized and managed in ArcCatalog. Right-click the geodatabase containing the replica and click Distributed Geodatabase. ArcToolbox also contains a full set of tools for creating, synchronizing, and managing replicas. These are located in the Distributed Geodatabase toolset in the Data Management toolbox. ; as * W « « • o * You can aiso synchronize and manage replicas in ArcCatalog. Right-click a replica in the Catalog tree and click Distributed Geodatabase. % cm mgiiw Tat* / MdOobritDf P ř«xrt iU*** 'j&rr* /■ - '.- ^ S^-chrorta gang«_J The Distributed Geodatabase toolset in the Data Management toolbox contains tools for creating, synchronizing, and managing replicas. Mapping and Visualization An overview of mapping and visualization • 264 Adding data to a map • 273 Dragging and dropping from ArcCatalog Adding data from a folder or other connection Adding data directly from the internet Adding x.y coordinate data Adding datasets having different coordinate systems Working with layers • 277 Controlling what's drawn on the map Managing data layers Setting the map extent and scale • 279 Identifying and locating features • 283 Identifying a feature on a map Identifying a feature using MapTips Locating a feature by searching Locating features via an attribute table Symbolizing data ■ 288 Assigning symbols to layers Shortcuts Assigning symbols using cartographic representations Using attributes to symbolize features ■ 292 Displaying quantities using a classification scheme Displaying categorical data using unique symbols Using charts to compare quantities Saving and reusing symbol definitions • 296 Saving a map layer as a layer file Importing symbol definitions from a layer or layer file Creating and storing custom symbols Saving a modified symbol Accessing styles and stored symbols Creating a new symbol in the Style Manager Labeling features • 300 Using map labels Managing labels on multiple layers Advanced label placement using Maplex Using annotation to label features 298 Drawing graphics on a map • 305 Using the Draw toolbar Drawing shapes and text Modifying a graphic Creating graphics from features Creating a map layout • 309 Working in layout view Setting up the page Navigating the layout Working with multiple data frames Using map templates Adding and arranging map elements • 313 Adding titles, text, and legends Adding scalebars. north arrows, and neatlines Modifying map elements Aligning elements Using grids and guidelines Navigating the layout Using draft mode Creating a graph • 318 Using the Graph Wizard to create a graph Adding a graph to a layout Modifying a graph Managing graphs Creating a report • 321 Creating a basic report in ArcMap Using Crystal Reports Creating relief maps and perspective views Creating a shaded relief map Creating a perspective view 325 Creating dynamic views and animations • 328 Navigating ArcScene and ArcGlobe Capturing a navigation path as an animation Creating an animation by capturing individual views Saving and modifying an animation Creating a time series animation • 333 Creating a time series animation using the Animation toolbar Creating an animation using Tracking Analyst 262 Using ArcGIS Desktop An overview of mapping and visualization The process for creating a map in ArcMap 264 Maps are the primary means for communicating geographic information. ArcMap is the primary application in ArcGIS for making maps. ArcMap is where you display and query datasets, where you display the output from your geographic analysis, and where you create finished maps for printing or for publishing over a network or on the internet. Beyond maps, storing geographic data in digital format on a computer gives you other ways of displaying information, such as perspective views, globe views, and animations. ArcScene and ArcGlobe™—included with the ArcGIS 3D Analyst extension—allow you to create perspective and globe views. The animation toolbar in ArcMap. ArcScene. and ArcGlobe allows you to capture a sequence of maps or views and play them back as an animation. The Tracking Analyst extension provides advanced capabilities for displaying and animating temporal data. As with other GIS tasks, creating a map—whether for simple display of your data or for creating a finished cartographic product for publication—is a process. Before creating your map. you'll want to give some thought to the purpose of the map and its design: • Who is the audience for the map? Are you making the map for your own use or to share with a few peers, or will it be presented to a larger group of people? Is the audience professional, or the general public? • What geographic area, or areas, does the map need to show? What is the map scale? Do you need to include a reference map showing a larger area? The map area (or extent) and the scale will help determine how much detail to show on the map. • Are there standard symbols or colors that are required (often the case in particular industries)? ■ How will the map be displayed or distributed? Will it be in a PowerPoint* presentation, in a printed report, displayed on a wall, or distributed over the internet? The size and media will determine how much additional information is required—such as legends, titles, labels, and so on. These are just some of the issues you'll want to consider. Several resources for learning more about map design and production are listed in the appendix. There are a few basic steps used to create almost all maps. For a specific map, you may skip some of these, or you may perform additional, more advanced tasks. Making a map is often an iterative process, so you may not always follow the steps in this order. 4 • Mapping and Visualization Open ArcMap When you open ArcMap (from ArcCatalog or from the ArcGIS program group on the Start menu), you re prompted to create a new map or open an existing one. The table ofcontents is initially empty except for a default data frame (named Layers), and the display window is A new. empty map * I 3Fg"3 ■ / i a- »- d.- J.- When creating a new map. you add GIS data to this empty map. The data can be: • stored locally on your computer, either on disk or on a CD/DVD • from a shared database or GIS server you connect to • on the Internet In any case, the data must be in a format ArcMap can read directly, such as a gcodatabase feature class, a shapefile. or a compatible raster format (see 'An overview of data compilation and editing" in Chapter 3). Find and connect to GIS data The next step is to find the data (from whichever source) and set up a connection to it if necessary. ArcCatalog provides an efficient way of doing this, since you can quickly see and preview large amounts of GIS data (See 'Finding and connecting to data" in Chapter ?) You can also search for data from within ArcMap. 265 Using ArcGIS Desktop Afteryou-ve~ from the Geography Network, or by entcnng the URL of a s.te contatntng Add data to your map ,'ve found the data you want, you add it by dragging itfrom ArtCtfatafe orby^ browsing to it Internet—eitb geographic data. Search for. preview, and connect to data in ArcCatalog. then drag the dataset to ArcMap... ...or search for and add data in ArcMap. using the Add Data button.. 4 ' Mapping and Visualization J 4 *-»D * _ 1-~ L-2LJ r=7FS-H «— 1 Reset the map extent By default, the map display is set to the extent and coordinate system of the first dataset you add. Depending on the extent of the individual datasets, and the order in which you add them to the map. you may need to change the map extent for the display window to show the area you're interested in. Two quick ways to do this are to use the navigation tools to zoom and pan, or to zoom to a specific layer. You can also set a fixed map scale or extent. Use the navigation tools to zoom and pan. or right-click a layer in the table of contents to zoom to it. ft3 • / ii a- Modify the map display You may also want to change the layer drawing order, set transparencies, or give layers more descriptive names (only the layer in the map is renamed, not the underlying dataset). ■ipmij Type over a layer name in the table of contents to rename it; drag layers up or down in the table of contents to change the drawing order; double-click a layer name and select the Display tab to set the transparency. 266 267 Using ArcGIS Desktop Assign symbols When data is added to the map to create a layer, a default symbol is assigned. The next step is often to change the symbols to make the map easier to read or to assign symbols based on attribute values (categories or class ranges). Click a symbol in the labia of contents to change the color. Doubleclick a layer name and select the Symbology tab to change the symbol, or to symbolize by categories or classes; select the Labels tab to label features. If you're creating a map to use for interactive query or to display the inputs and outputs from an analysis, you'll likely use simple symbols that make the map easy to read on the computer screen. If you're creating a map for publication, you'll likely spend more time on assigning symbols—perhaps using a set of standard symbols or even creating custom symbols—to ensure the map effectively presents all the information you want to convey to the readers. In any case, you'll want to choose symbols with some thought for how they represent the layers and how they appear with each other. Create labels and graphic objects You may also want to label features with descriptive information, or add graphic objects to highlight aspects of the map. For a simple map being used to display data, basic map labels or graphic text will suffice to identify features. If you're creating a map for publication, you'll probably want to create annotation, which lets you place and edit each text string individually (see -Creating and editing annotation' in Chapter 3). 4 • Mapping and Visualization Organize the data Data is added to the active data frame (there is only one to begin with, but you can insert more). Use additional data frames to group datasets or to create multiple data views on a single map (especially useful for published maps). li «b• ft■> ^ ■ ♦ r •. ■ ft'-*—. • B <• mm* * • * - - H mmm - B O o - a n H a - »—»- > - A • Use the Insert menu to add data frames. Right-click a layer name to copy or delete it. If you're making a map to explore and query your data, at this point the process is pretty much complete. You'll likely continue to work with the map—possibly changing data classification schemes, removing or adding datasets as necessary, performing queries, making measurements, summarizing attribute values, creating charts and reports, and so on. If you're making a map for publication, you'll undertake a few additional steps. Create a map layout The first step in creating a map for publication is to create a map layout on the page. To do this you switch to layout view, which shows you how the data frames will appear on the page. You can move and resize data frames, and add new ones to show multiple data views on a single page. - Nat nmti i*a »» a* •nam ■ >..•* (TT» 3 u *-»anr r- ■ □ 3 ,___'.. Use the View menu to switch to Layout View. Then select a data frame on the page to move or resize it. 268 269 Using ArcGIS Desktop In fact, if you know your map is for publication, it's a good idea to have a sense of the layout you want before you start creating the map. You'll want to at least set up the page size and orientation (on the File menu). And. while you can insert new data frames and move layers around after you've added data to your map, it's more efficient to create all the data frames up front and place the data in the appropriate data frame as you add it to the map. Add map elements Finally, you'll add map elements to the page, such as legends, titles, neatlines. scalebars, and north arrows. You might also add charts, reports, text blocks, and logos. Once you've arranged the various elements, you're ready to print the map or publish it to the Internet. -------------,- a b 8 □□□□ • -«~3 a b » CO'.*-.. Wab Use the Insert menu to add legends, titles, and so on. To move an element on the page, select and drag it. 4 • Mapping and Visualization Visualization— other ways of looking at GIS data Visualizations, such as perspective views, animated fly-overs and globe views, and time-series animations, can be an effective way of presenting information, especially to audiences not accustomed to reading specialized maps. Perspective views are created using the ArcScene application in ArcGIS 3D Analyst. 3D Analyst allows you to navigate through the scene interactively as well as capture and store animated fly-throughs. For realism. 3D symbols, such as trees or light poles, can be added to the scene. Use an elevation surface—or any other surface with z values—to create a base for the perspective view. Then drape other layers on top. ArcScene also lets you extrude features to create, for example, a 3D model of buildings in a city, or a perspective view of a thematic map. ArcScene lets you extrude features to create 3D maps—in this case, showing the relative population of each county. 270 271 Using ArcGIS Desktop Globe views are created using the ArcGlobe application, included in ArcGIS 3D Analyst A key feature of ArcGlobe is the ability to reveal more detailed layers of information as you zoom in. As with ArcScene. you can work interactively—rotating the globe, zooming in and out—and capture the navigation path as an animation. X The default view in ArcGlobe includes a shaded relief image of the earth. Add your own local, regional, or global layers. Maps in ArcMap can also be used to make animations. The Animation toolbar lets you capture a series of increasingly zoomed in views, or create an animation that pans across a region. Time-series data can be viewed using the Animation toolbar or using Tracking Analyst. You can step through the data, or create, store, and replay animations. You might animate the path of a storm over several days, for example, or the population growth in each county over several decades. 0* 10 mi'. ~3 itttov A- *- J.- —• Use Tracking Analyst to animate movement or change over time—in this case, the path and strength of a stomi. 4 • Mapping and Visualization Adding data to a map There are several ways to add a dataset to a map drag it from ArcCatalog. use the ArcMap Add Data dialog box to browse to it. add data directly from the Internet, or add a table of features that have fields containing geographic coordinates. When you add a dataset. it becomes a layer on the map. Once you've added a layer you can display the dataset and its associated attributes. A layer references the underlying dataset. so on a single map you can have multiple layers created from the same data, each drawn with different symbols or representing different attributes—for example, one layer of census tracts showing population and another layer of the same tracts showing median income. Dragging and dropping from ArcCatalog You can drag data from any folder or connection that appears in ArcCatalog (in either the tree view or in the Contents panel) and drop it onto the display window or table of contents in ArcMap. The data is added as a layer on the map. See Finding and connecting to data' in Chapter 2. Select and drag a dataset from the ArcCatalog tree view.... ) a u * Mf> - ■ ♦ : .j« '" fz a!% % % * ;■ r t q f * a »«B BBDSJBBptJ 'jIhhi ~~3 J AOO * * - -r "1 a£ W - t* fat > d I'll • ■ <" > « * P*^- I h '* * b t * if* *|* "3 -j! *-»>o If? - -I 3 - 1 IF] im A«»-i-: Drag tf?e parks dataset from ArcCatalog to a position above parcels in the table of contents to have parks draw on top Adding data from a folder or other connection In ArcMap. use Add Data on the File menu, or the Add Data button, to locate and add data to the map—any connections you have established show up on the list. You can also add a new connection, as well as display the thumbnails for the datasets or a list with dataset details such as file type. In other words, the Add Data dialog box is like a mini-ArcCatalog. Use either the Add Data button on the toolbar or the Add Data option on the File menu to open the dialog box.... ...then navigate to the dataset you want to add. use the buttons on the nght to Open a new folder view icons, a list connection or thumbnails 1 «■! al»UI[7Ta|a] OtaeCodnM $ Nadu* feed CtM4> ^owi em Cnma.^ ^rtwioei'irtsJpt 4> &•>■>•] irtfM *>f*c**v 4 ■ Mapping and Visualization Adding data directly from the internet To add data directly from the Internet, use Add Data from G1S Portal on the File menu. If you know the URL of a metadata server, such as a regional GIS data clearinghouse, you can enter it and go directly there to access available data. Or, you can go to the Geography Network and search or browse for data to add to your map. Much of the data ii free; some requires a fee to download. Select Add Data from GIS Portal on the File menu to go directly to the Geography Network or to enter the address of a Web site. fMCaaraS (aaac* 1181 x « :: o a \ thai match what Pc, typed *i appear CR» the place you want n tt*t Mt to cheat* it. >*" » BO» on the map *-in the B tool to define the are* you ■ to tearcn » by ■Memo, a ••yword That* enact* f* aptejnei I Okalaorcti The Geography Network lets you search for. and download. GIS data. Enter the URL of an ArclMS metadata service, such as a regional GIS data clearinghouse 274 275 Using ArcGIS Desktop Adding x.y coordinate data To add data from a table of locations, such as data collected with a GPS unit, use Add XY Data on the Tools menu. Each location must have associated x and y coordinates stored in separate fields, as well as a unique identifier. Use Add XY Data on the Toois menu to open the dialog box and specify the name of the table, and the fields containing the coordinates. * * » #1 3 • - a h . o • A - |f — 3fS~3 mi g A - > - ^ - -1 MAJNTENANCE-C POHTJt PONT_Y JOTBB 84375 37BB2BD 00000 «SSM 656Ä 3768343 35000 «3131 15625 37682*7 BODOO 4931B4 1-5000 37BB175Ä0rjO nubfcc Slag* Cut McUk* School Cmfwitar Hospital Laurel hWdk Srhool Pubis LnVjrj- 3766216 75000 3767EZ2 0000G 3768111 75000 SSBB30 75DD1 376S543 00000 3766232 76000 J7G9B6B 75000 376319200000 Iii Adding datasets having different coordinate systems The coordinate system for the data frame you're adding layers to is that of the first layer added, by default, but you can also set the coordinate system manually. If you're adding data from various sources, rather than data stored in a single geodatabase. the coordinate system of the dataset might not match that of the data frame. If a spatial reference is defined for a dataset you're adding, ArcMap projects the layer on the fly (the spatial reference of the underlying data is not modified). If a dataset does not have the same underlying geographic coordinate system as the data frame or if the dataset you're adding does not have a spatial reference defined, warnings are displayed. See "Defining coordinate systems and projecting datasets* in Chapter 3 for a discussion of assigning a spatial reference to a dataset. This warning means the dataset you're adding does not have the same geographic coordinate system as the other data in the data frame— ArcMap projects it on the fly. but it may not register correctly. This warning means the dataset you're adding does not have a spatial reference defined—if it is, in fact, in the same coordinate system, it will correctly register, otherwise, it may not. 4 • Mapping and Visualization Working with layers WTien you add a dataset to a map. a layer is created. In the course of making your maps, you'll add and remove layers, turn them on and off. change the drawing order, and so on. to display exactly the data you need to see and work with. Controlling what's drawn on the map You use the table of contents to control how the layers are displayed. Use the check boxes to turn layers on and off. Use the + and - signs to display or hide a layer's legend. When you add data to create a layer, the layer is assigned a position on the table of contents based on its data type. For example, lines are added above polygons, and points are added above lines. New layers are positioned above existing layers of the same type. The order in the table of contents determines the drawing order on the map—a layer draws on top of layers listed below it in the table of contents and under layers above it.) Change the drawing order by clicking a layer name in the table of contents and dragging it to a new position. Tum layers on and off Drag $ layer to change the drawing order (a layer draws on top of those listed below it) Display or hide the legend Managing data layers The table of contents is also where you rename, copy, or remove layers from the map. Since a layer points to an underlying dataset. if the dataset is moved or deleted, the link is broken and the layer can't be drawn on the map {a red exclamation mark next to a layer in the table of contents indicates this). Use the layer's properties dialog box to reset the source (right-click the layer name and click Properties at the bottom of the context menu) or click the exclamation mark. The properties dialog box also lets you access all of a layer's properties, including how it's symbolized, which features are displayed, and so on. It can also be opened by double-clicking a layer name. 277 Using ArcGIS Desktop Layers can be copied as layers on the same map. saved as layer files to be added to other maps, or exported to new datasets (you'd do this to create a new dataset containing a selected set of features in a layer, to be used in analysis). To save a layer file, or export it. right-click the layer name to display the context menu. Right-click a layer name and click Copy; men rightelick the data frame and dick Paste Layarts). □ EtB« ■■ »« • . »r ~l - - a A red exclamation mark next to a layer in the table of contents indicates the link is broken. If the source has been moved, right-click the layer, click Properties and select the Source tab. Click Set Data Source and navigate to the dataset. Export layer to a dataset Save symbolized layer to a file Individual layers within a data frame can be grouped by creating what's known as a group layer. The layers can then be managed as a unit. When you turn the group layer on, all the layers in it are displayed. Group layers are especially useful if there are many layers on your map. or if you have layers that are always displayed together on maps. Using group layers is also an efficient way to share data and maps. A group layer can be copied or saved as a file—all the layers in the group are saved or copied together. To create a group layer, right-click a data frame name in the table of contents and click New Group Layer. You then drag individual layers under the group layer, or copy and paste them. 7b create a group layer, right-click the data frame name in the table of contents and click New Group Layer. Then drag or add layers under the group layer. Click the group layer check box to turn all the layers on or off. If the group is on, individual layers under it can be turned off; if the group is off. the layers under it will not be displayed. 4 • Mapping and Visualization Setting the map extent and scale The map extent and scale determine the geographic area that is displayed on the map. ArcMap includes a number of ways to set the map extent. You can zoom in and out and pan the display, step through or save extents. Create a Bookmark from the View menu to save and return to the current extent. Zoom In (click or drag) Fixed Zoom In Pen Back (Previous Extent) it o M - To zoom to a fayer's extent, right-click the layer and select Zoom To Layer. Zoom Out (click or drag) Fixed Zoom Out Zoom to Full Extent (all layers) Forward (Hext Extent) You can undock this toolbar and let it float, or dock it along any edge of the ArcMap window—as you can with any of the toolbars. The My Places option on the Tools menu lets you create a list of frequently visited locations that you can zoom or pan to. The places can be created from the current map extent or from a selected feature (or features). Unlike bookmarks, which are stored with the current map document, your My Places list can be accessed from any ArcMap map document. ArcScene view, or ArcGlobe view. UJfl bemTa ] ■■« -i **§!• -j Mum I "-MM 1 «1 1 .[ 1 <- 1 278 Access your My Places list from the Tools menu. You can view and add to the list ,n>m any map. scene, or view. 279 Using ArcCIS Desktop 4 • Mapping and Visualization By default, the full extent of the first dataset you add to a data frame becomes the initial extent of the map display (for that data frame). If you add a dataset that extends beyond that initial extent, only features within the extent will be visible (use the Full Extent tool to zoom out to the extent of all layers). * «<• s -3 w ~3fi~3 ■ ' 1 A- 77?e display is set to the extent of the parcel layer. The streets layer extends beyond this extent. The current map scale is displayed in the scale box at the top of the ArcMap window. To specify a map scale, type the scale in the scale box—the map display is adjusted to the new scale. The drop-down list lets you pick from standard map scales; any scale you type in is added to the top of the list so you can quickly get back to it. You can also customize the list by adding or removing scales. You often set a particular map scale when creating a map for printing or publication. use me scale box 10 set a map scale. jisi Click Customize This List to remove scales from the drop-down list or add your own scales to it. You can also control the scale at which layers are displayed—some layers (usually more detailed ones) can be set to display only when you're zoomed in to a small area. ^ v * • - - * ■ ■ ir i > - #1 3 - * A ■■-rt,. - - . r > IBM • WMM * ■ - > 3- a- . rr^ With a minimum scale set to 1:20,000. parcels are displayed when the extent is zoomed in to 1:15,000 (above) but aren't displayed when the extent is zoomed out to 140.000 (below). A small scalebar appears under the grayed-out check box lor the layer to indicate the layer is outside the visible scale range. Htm [Mfr zwm ft !<-«» —1—■»—i~ 280 281 Using ArcGIS Desktop To view the data at several scales at once, use a Magnifier/Viewer window. In Magnifier mode, the window magnifies whatever it is over when you drag and release the window's title bar (in Update While Dragging mode it acts as a magnifying glass as you move the window over the display). In Viewer mode, the window takes a snapshot of whatever it is over. When you drag the window, the snapshot stays in it, so you can view one area or scale while continuing to zoom and pan in the main display window. A Viewer window allows you to pan or zoom, display the full extent of the map. or display the previous extent (or next extent). It's essentially a free-floating display window. You can open as many of these windows as you want. An overview window shows you the location of the current extent within the full extent of the data frame. Open Overview and Magnifier/ Viewer windows from the Window menu- Click and drag the window's title bar to position the window. To resize the window, drag an edge. □ s* y * * * - < Viewer window ■ a- < mum ~3 JL • \ \ \ Overview window Magnifier window > j \ \ ~3Fv3 ■ J m A- J.- —■ You can toggle a window between Magnifier and Viewer mode by clicking the menu button on the window. ~4 \js? Click the menu button on a Viewer window to Rash the location in the main display window. Use the Pen tool on the Tools toolbar to pan within the viewer window; then use Pan To Location to pan to that area in the main display window. Click the menu button on a Magnifier window to switch to Update White Dragging mode. You can also switch a window between Magnifier and Viewer mode. 4 • Mapping and Visualization Identifying and locating features Maps in a GIS are sometimes referred to as "smart maps" because—unlike paper maps—you have the ability to point at something on the map and get information about it (specifically, all the information about the feature stored in the layer's attribute table). Conversely, you may know something about a feature, such as its name, but not know where it is on the map—you want to enter the feature's name and locate it on the map. ArcMap includes several tools for identifying and locating features. Identifying a feature on a map Use the Identify tool to point at a feature on the map and display its anribute values. The information appears in the Identify Results box. Once you've identified a feature you can click it in the Identify box and it will flash on the map. Hold down the Shift key while clicking a feature to add it to the list of identified features (otherwise it will replace the previous feature), or drag the cursor to create a box around the features you want to identify. 2 i* b m it-'::: - -I D ■ ■ a ~3 :/*••□« \ When you click a feature on the map its attributes appear in the Identify Results box. M 1 V«ta 1 FtDJ 1 MM CfelU ha.M(*j.**3 -D 222 iwr.rwr XO Press and hold the Shift or Ctrl key while clicking features to add them to the results box. You can also add several features at once by dragging to create a box around them. 283 Using ArcGIS Desktop 4 • Mapping and Visualization You control which layers to identify features from—choose all layers, a subset, or a specific layer (the topmost layer in the table of contents is the default). Use the drop-down list to specify the layerfs) from which you want ti identify features. - :.»*....■«« Inbi H 323hj IJJJBSSD— KC MtWTIrWKIV 27 UufT.nrtl 100 By default, all the attribute values for the identified feature are listed. The fields listed in the box can be controlled using the Fields tab (uncheck the fields you don't want displayed). o aam "3 J t-ma v SID I imm* I jot t tarns I ■a— Mat* !-> Ir_ 1— ip-- lfc-*-f—í 1 Ft 1 OOTID * 9 • :: am i'tMMTIrMH mxi.v MW Sot. 21 nMTJt 0«ut» ■ POMI Y Data ? 60 ^ I « I I 77ie Fields tab on the Layer Properties dialog box lets you specify which fields will appear in the results box. 284 If you're having trouble picking the feature you want, change the Selection tolerance—choose Options from the Selection menu (setting a larger selection tolerance will select features farther from the cursor). - Selection tolerance Identifying a feature using MapTips A quick way to identify features is to use MapTips. When MapTips is turned on for a layer, placing the cursor over a feature displays the feature's name (or other attribute). If MapTips is on. the tip will also appear when you use the Identify tool—you can make sure you have the right feature before clicking it to display the additional attributes. To turn on MapTips, right-click a layer and select Properties to open the Layer Properties dialog box. then check the Show MapTips box on the Display tab. í I 0 Hot- ^1 • DO Not* • 0 0 Not. T] Set the attribute to be displayed by specifying the Primary Display Field on fhe Fields tab. 1 285 Using ArcGIS Desktop 4 * Mapping and Visualization Locating a feature by searching Use Find on the Edit menu (or the Find tool on the Tools toolbar) to locate a feature by typing an attribute value. Once you' found the feature you want, you can flash it on the map or zoom to it. To locate a feature and have it stay highlighted on the map. select it in the layer's attribute table. Click the gray box (or ritzht-click and click Select/Unselect). To select multiple features and highlight them, press the Ctrl key while clicking the gray box next to each feature's record in the tabic. ♦ F ~3 -j> «v*>a ►.■ Fn; ■ . - Use Find on the Edit menu to search for a feature by attribute value. You can also find named places, such as states or cities, within your map extent, street addresses, or locations along a route (if you've already defined one—see 'Adding specialized datasets to a geodatabase"in Chapter 2). Right-click a feature in the results list to display options including Flash on map. Zoom To feature, Identify, and more. When you select a feature in the layer's attribute table, the feature stays highlighted on the map until you select another feature. Locating features via an attribute table There may be instances when you prefer to locate a feature (or several features) on a map by scanning through a layer's attribute table—to find several features by name or ID. for example. Once you've found a feature in the table, right-click the gray box at the beginning of the row to flash that feature on the map. You can also zoom or pan to the feature, or display the Identify window. 7b use an attribute table to locate a feature on the map, right-click the gray box at the beginning of the feature's row, and select an option from the menu. Press and hold the Ctrl key while clicking to select multiple features and highlight them. With this method, you're actually creating a selected set, so when you're done highlighting features you'll want to clear the selection (see 'Selecting a subset of features' and 'Working with a selected set* in Chapter 5 for more on feature selection). Right-click the gray box next to any selected feature and click Clear Selected. 286 287 Using ArcGIS Desktop 4 • Mapping and Visualization Symbolizing data Specifying trie symbols you use to draw features on a map lets you ensure that the map is easy to read and conveys the information you want. For some audiences, standard symbols are immediately recognizable. Different feature and attribute types are drawn using different types of symbols—points with marker symbols of a specific size and color, lines with symbols of a specific width, partem, and color. Areas can be drawn using an outline, or filled with a pattern or color. Assigning symbols to layers When you add a layer to a map, ArcGIS assigns a default symbol—all features in the layer are drawn using the same symbol. To change the symbol, right-click the layer name and click Properties to display the Layer Properties dialog box. Then choose the Symbology tab. (You can also get to the Layer Properties dialog box by double-clicking the layer name in the table of contents.) Pick a method of symbolizing the features, then specify the symbol(s). □ sam "3 j. v A- »• J.- -- Layer Properties dialog box for point features. • I L**| J*nlHMM| » I Select a predefined symbol from this panel in the Symbol Selector dialog box. The Symbol Property Editor lets you modify alt the properties of the symbol. You also use this dialog box to create custom symbols._ warn Ijw |5«--rfJ 1*™ Í p + M- 1 d - F=l *mmm KOM (CmOCl -tj tk*_&*> J ■] ťo*M faoom *j OiOiTh ft°™ ij ♦1351Ä4I SIS bM t/se these options to modify basic properties of the current symbol. Adding a style gives you more predefined symbols to choose from— just dick the style on the list. ArcGIS provides a number of styles: you can also create your own (see Creating and storing custom symbols'}. 288 You can also draw features using symbols based on the attribute values of the features—for example, roads of type •Highway" would be drawn using a wider line symbol than roads of type "Local" (see the next section, 'Using attributes to symbolize features"). Raster datasets that represent categories, such as vegetation types, are initially displayed using a default color for each category. Raster datasets that represent continuous values, such as elevation, are initially displayed using a grayscale color ramp, with lower values drawn in darker shades. If the raster is a multiband image, such as a satellite image, it draws in its defined RGB values. As with feature datasets. these symbols can be changed via the layer properties. The specific options in the Layer Properties dialog box depend on the type of data you're symbolizing and the method you're using. Layer Propedies for line data Layer Properties for polygon data Layer Properties for raster data with continuous values The symbol specifications are stored with the map, so once you've saved the map. the data will be symbolized the same way the next time you open the map. You can also store symbol specifications to use on other maps—see 'Saving and reusing symbol definitions' later in this chapter. Shortcuts Clicking a symbol in the table of contents lets you specify- symbols directly, without opening the Layer Properties dialog box. Symbol Type • Marker Line ■ Area Fill ■ Classified or categorized raster Stretched raster Left-click opens.. Right-click opens.. Corresponding Symbol Selector Dialog Color Palette Color Selector dialog Color Palette Select Color Ramp dialog 289 84 Using ArcGIS Desktop 4 • Mapping and Visualization Assigning symbols using cartographic representations Assigning symbols to map layers in ArcMap lets you to portray features using basic properties such as color, line width, pattern, and so on Sometimes, though, you'll need to depict the features—and the relationships between them—in a more realistic way. For example, you might want to create a transportation map showing overpasses, bridges, and tunnels. On a map of voting districts you might want to more clearly portray adjacent boundaries, rather than simply showing a single shared line. Or. on a map of building locations, you might want to rotate the building symbols (representing point locations) to face the street they're on. Cartographic representations allow you to do this. Using cartographic representations for the various feature classes, bridge symbols are added around road symbols where streams and major roads intersect—with stream lines ending at the bridge—and small squares are placed at house locations and are oriented along the roads they face. A cartographic representation is a set of rules, overrides, and graphical edits that allow you to represent geographic features cartographically without having to change the shape or location of the underlying data (which is, after all, an accurate representation of the features in geographic space). For example, if a road runs parallel to a river, it may be that at the map scale you're using, the two lines appear to touch or cross. You can use a cartographic representation rule to ensure that the road is offset from the river when drawn on the map (without having to actually move the location of the road or the river, which could affect other maps or any geographic query or analysis you perform). Cartographic representations in ArcMap also include a series of tools to perform graphical edits directly in the GIS without having to export the cartography to a graphics package—for example, removing a portion of a line that obscures another feature. Cartographers refer to this as "map finishing and editing." 290 Cartographic representations are created w ithin a geodatabase. They are stored as columns in the feature class attribute table and in system tables in the geodatabase. A quick way to create a cartographic representation is to convert the symbology for an existing layer on a map. Once you've converted the symbology, you can edit the representation, if necessary. To create a feature representation for a feature class from existing map symbology. right-dick the feature class in the table of contents and click Convert Symbology to Representation. You can store multiple representations of the same feature class. For example, you could have one representation of parcels for a local zoning map and another representation for a general plan map. You select the representation you want after you add the feature class to a map (using the Symbology tab on the Layer Properties dialog box). This approach eliminates having to create and store several layer files for a feature class, each having different symbology. 5— , IIMM —rrri.uuiu.ll_L *■«••-«-»•» _h _ i / d a.• 11*1 ~| En- I Mt I After adding a feature class to a map, open the Layer Properties dialog box and select the Symbology lab. Any defined feature representations wilt appear under the Representations heading— select the one you went to use. You can also modify the representation here. Cartographic representations are useful if you create maps for publication—especially if the same feature classes are displayed using different symbology on different maps. Anyone in your organization who has access to the geodatabase also has access to the symbology for a feature class. You can also create a representation directly in a feature class, using ArcCatalog. This method also gives you the option of importing the symbology from an existing layer file. 291 Using ArcGIS Desktop 4 • Mapping and Visualization Using attributes to symbolize features When you add a dataset to a map. ArcMap draws all the features using the same symbol. Often you'll want to draw the data symbolized by an attribute value (almost always the case for contiguous areas). The symbol used to draw each feature (the marker size, line width, or area color fill, for example) is determined by the value of a feature for a particular attribute. Displaying quantities using a classification scheme Many numerical attribute values can reflect measurements—for example, population counts or percentages, measurements of rainfall, and so on. Such values can be classified into ranges of values, and each range assigned a symbol for display purposes. When you specify the attribute value to use. a default classification is assigned. You can modify the classification scheme, the number of ranges, and the class breaks. Hi Right-dick a layer and dick Properties to open the Layer Properties dialog box; select the Symbology tab. « J C— | _ Specify a classification scheme and number of classes, and ArcMap will set the class breaks for you. Choose a symbol type under Quantities—when you specify a field containing the numeric values. ArcMap assigns a default classification. Drag the dass break lines on the histogram to set breaks manually, or type the break values in the box on the nght 292 Select a color ramp from the drop-down menu, or set the color of a class by double-clicking it to display the Symbol Selector. S*-___ r--_ | AGE J \otam ~3 HMumBmHuUartui ~3 a— F"3 1 ns m BB*T1Q 4750 ^^■«751 3351 1037 1325 1926 3009 3010'«7» 1751-9351 Change the label by selecting and typing over it. ' Sto- dan rangai urg htMUa v«m -3 ■— ■1 □ □ □ □ □ ~~ m\ □ □ □ — 1 1 n ■ ■ Right-click in the box for more symbol options. Double-click a symbol to display the Symbol Selector dialog box and specify a new symbol. To create a custom color ramp, set the starting and ending colors then select Ramp Colors from the context menu (above). Normalize your data to account for differences between features. Normalization divides the values of one attribute by those of another to create a ratio. For example, if you're mapping counties that vary in size, you might normalize the population by the area of each county (to map density of people per square mile), or normalize the number of seniors by the total population of each county to map the percentage of seniors in each. IHmaJ I San* i Sataaon | Dapfe Sjwbobor [fate | Dafeibm Quai)i | Labah | J> Vai* |aGE.E5.UP J QanfcMian N(Wa(Bw*iUo»*i| 1 ll □■Da* [s T] Oattfr 1 Cabrfeav j •alHi^ 451 G3S t 1(337 1325 11926 3009 I 301D 4750 1*751-3351 451 IDS 1037 -1985 1926 3003 3010 4750 3351 I Sowca I SakKtan J Dwdw Sf"b*w | 2 Normalization Held m^LWLmmmmmiiM I DaMonOwrj Labak | im I M»n | ft* v*» |A£f a up j Mi-nataa*cn|P0P2rjC0 J C*n#jiu«rtw>|iw| ■- rug Text editor tm !».. 4 %m f: 3 J - »l*liH •» fi«-3 v«.F~l rim «1* f~ 1 ■« -ir=-3 1 -2SJj 298 4 • Mapping and Visualization te The Style Manager is accessed from the Tools menu. The left panel displays the folders for the currently loaded styles-the right panel d.splays the individual symbols for the selected style and folder. ^ Cd Slyles' Open the Style Manager from the Tools menu. * **** <>ESU JJKJ| 30-« BMkj Maw v a- li^r- To label an individual feature with its name or other attribute use graphic text—specifically, the Label tool (see the next section 'Drawing graphics on a map'). This tool is useful for labeling one feature, or a few. It also lets you use a different text symbol for each. Managing labels on multiple layers While you can manage each layer's labels from the table of contents, the Label Manager lets you modify the label settings for the various layers within a data frame from a single dialog box. It also includes options for managing label placement by giving labels for certain layers higher priority or greater weight (labels with a higher weight take precedence over those with a lower weight). • * u a r > ♦ I- • -l 3 ■ ■ a "1*1 tlfttt Right-click the data frame name I and select Labeling to display , 5 label management options. _M_Jj_i_J \ H 5acmd*y 1 =55 -J AaBtYyZf HIT/ill ~ 1 Plicmn 0 i l*l r hmi.i. 0 PMH ^CM r wu i i Mai r mm. __ ^ t/se i.a*e/ Manager to see and modify all label classes. 301 Using ArcGIS Desktop These options are also available from the Labeling toolbar (click the View menu, point to Toolbars, and click Labeling) The Labeling toolbar Labels will remain the same size as you zoom in or out on the map. If you want the labels to get larger or smaller as you change the map scale, set a reference scale for the data frame. The reference scale specifies the map scale at which the size of the labels on the map matches the defined size of the labels in page units, such as points. Typically, you'll set a map scale (or interactively zoom) to show your area of interest, set the reference scale, and create the labels using an appropriate text size for the current display. When you zoom in or out, the label text size will increase or decrease, accordingly. To set a reference scale, right-click the data frame containing the features you're labeling, point to Reference Scale, and click Set Reference Scale. The reference scale will be set to the current map scale—labels will appear at their specified text size at this scale. With a reference scale set, labels will be larger than their specified text size when you zoom in, and smaller when you zoom out beyond the reference scale. Advanced label placement using Maplex The Maplex for ArcGIS extension enhances cartographic design with a sophisticated set of rules that automatically modify labels so they can be placed correctly. Maplex can save time by automating much of the work of manual label placement. The text placement rules include positioning, label fitting, and conflict resolution. You can also create rules for text stacking, font reduction, curving, and abbreviation. These rules are useful when you're creating complex maps for publication that include many features and numerous levels of labeling. They're accessed via the Label Manager and Layer Properties dialog boxes. 302 4 • Mapping and Visualization Maplex is included with an Arclnfo license. Once the extension is enabled (see The ArcGIS Desktop framework in Chapter 1). select the Maplex labeling engine (the default is the ESR1 standard labeling engine). Select Maplex as the labeling engine from either the Data frame Properties dialog box or from the Labeling toolbar. ~3 . Whan the Maplex labeling engine is used, the Placement Properties dialog box gives you additional options tor label position, fitting, and conflict resolution, as well as for label ranking. T lit W - a -fur. Public « PuMIc Lfcrwy Pole. . , H.*lqu«rt.r ■f In this example, rules have been defined to stack labels and to ensure they don't overlap streets. 303 Using ArcGIS Desktop Using annotation to label features Annotation allows you to place and edit text individually. This is useful if you need to control the exact positions of labels. A quick way to create annotation for all features in a layer is to convert existing map labels using the Convert Labels to Annotation option on a layer's context menu. You can then select and work with the individual text strings. Annotation automatically scales with the features as you zoom in or out (a reference scale is set—using the current map scale—when you convert labels to annotation). in....... * J- Right-click a layer in the table of contents and select Convert Labels to Annotation. The Label tool described above is also a way of quickly creating annotation for individual features (as opposed to all features at once). Map document annotation is stored only with the particular map in which it is created. If the annotation will be used on different maps, create geodatabase annotation. The annotation is stored as a separate feature class in the geodatabase and can be accessed by many users (see 'Creating and editing annotation' in Chapter 3). 4 • Mapping and Visualization Drawing graphics on a map Adding graphics to your map can clarify the information that the map conveys. For example, you might add circles on top of the data on your map to draw attention to particular features, outline a study area with a polygon, or add lines that point to potential locations for new stores. Graphics are saved in the map document. Using the Draw toolbar Graphics are created using symbols—markers, lines, fills, colors, and text—that you access from the Draw toolbar. By default the Draw toolbar appears at the bottom of the ArcMap window. As with all toolbars, you can move and dock it anywhere on the window, or let it float. is Apia i . it 3 ■ ■ ~3 j-'- I I \ \ \ Set the text font \ Use these buttons to set the text, properties here, filt, line, and marker colors. k - O - A - '□tao A *i> ■<= O f f\. ■» • • -□□□□□□□□LB □■■■□■■I Use the drop-down tists to display shape and text options. The Drawing menu lets you arrange selected graphics and set default graphic symbol properties. Specify a custom color. Click the menu button to change the color model. 304 305 Using ArcGIS Desktop Drawing shapes and text The tools on the Draw toolbar for creating shapes and text work just like tools in a drawing program. \ Click and drag to create a rectangle. X \ X ~3FT3 ■ / ■ A.- +- J.- . New Rectangle tool ,---_-_-----------Z Click and drag \ graphics to move them. A A- »• V--' 1 •unnwu» Sefec/ Elements C//cfc to enter the vertices of a polygon. \ Nekv Polygon > - ■ »r - .r^3 • A i , ' pj- Cftc* the text position * and type in the box. — I ! \ ^ 4 J : at a* im« ' ■ ♦ I v^ y Drag a handle to resize the graphic^. u p. • a- ■ 2 * a* i»ix " ■ * r I. Use the Edit Vertices . tool to move a vertex by, ^ clicking and dragging. ^ ^ ~3rT-3 • / I A," »- J Ed/f Vertices 4 • Mapping and Visualization The text drop-down menu provides a variety of options for placing text. Label feature using CBilout box I Ntw Locator) A « A-"" *' pas >" \ .Fsrasi * ^ ^ ■wr^—1 pas These three tools let you create a polygon, rectangle, or circle containing text that Hows within the shape or is in multiple columns. Label feature with attribute Any shapes or text you draw while in Data view are drawn in geographic space—they move and scale with the eeoaraphic data as you pan and zoom. They appear in both Data and Layout view. Any shapes or text you draw while in Layout view are drawn in page space—they move and scale as you pan and zoom on the layout page. They're stored with the layout and appear only in Layout view. You can add graphics to a data frame {in geographic space) while in Layout view by clicking the Focus Data Frame button on the Layout toolbar (you can also double-click the data frame on the page or right-click and click Focus Data Frame). Modifying a graphic Each graphic object has a context menu that lets you work with the object. Right-click the object to display the menu. Use the Properties option to modify the object's symbology. Right-click any graphic shape or text to display more options. Choose Properties to set the color, font and position. (You can also double-click the graphic to open the Properties dialog box.) \ \ \ —^31 306 307 Using ArcGIS Desktop 4 • Mapping and Visualization Creating graphics from features An alternative way to create graphics is to convert features to graphic objects. You'd do this if. for example, you want to highlight a particular feature but don't need or want to create a new layer containing only that feature. You'd select the feature, convert it to a graphic, and modify its properties to assign a new symbol and color. mm J -J A • □ W V \ \ Right-click a layer and select Convert Features to Graphics to turn geographic features into graphic objects. 308 Creating a map layout Map layouts are used to compose a finished map for printing or publication. When you create a layout, you arrange the various map elements—the geographic data itself (contained in a data frame), as well as explanatory information, such 35 titles, legends, scalebars, and so on. The ultimate goal is to present the necessary information as simply and clearly as poss ible. Working in Layout View Lavout View shows you how the map page will look, and lets you display rulers and grids to help you arrange the map elements (see the next section. 'Adding and arranging map elements'). Select Layout View on the View menu. The buttons at the bottom of the ArcMap window also let you switch between Data and Layout view. data View ■ — Layout View Setting up the page The page setup defines the size and orientation of the final map. the printer you'll be using, and other settings. Cats* » • - • r ./.p.f.f.r.r.f m 0*»___B*M F 1*1*1 i To specify the page parameters, right-click anywhere in the display window and click Page and Print Setup (or select Page and Print Setup from the File menu). 1*1 HPLotal—MSOPaE Vtm* doti.hb ■**o • k 4> □ • a • : ■: la *- ~3F5~3 ml' *j/- — - 3 13 =0 309 Using ArcGIS Desktop 4 • Mapping and Visualization Navigating the layout Layout View has its own set of navigation tools that work on the page, contained on the Layout toolbar. They are distinguished from the data navigation tools by the page icon. You can work with the data in the data frame in Layout View just as you would in Data View—any changes you make in the Data View are reflected in Layout View. However, it's often easier to switch to Data View to work with the data and then switch back to Layout View to work with the page layout. ~3 4 na w These tools work with the data inside the data frame— 3 just like in Data View. Pen the data in the data frame ■ 1" ' \ « □ - A • ClttTS i* t* > □ at B a 1 jmnn These toots work with the entire page—they're activated only in Layout View. 3 a B a * i 3 « Layout toolbar p tf gia/BEBM ■---81» J £ Éémtm - jmar ■tt*W - Off*" * «*■*.-- - - 0 •- N •- - 11«! *| = -■"?■-.r mm inMSir j*l '.-Měr HaaM | teror. r a,o ha0«tv«a art r AiPlnta* ■ Jl ■ M M ■ Right-click the data frame and select Properties to explicitly set the size and position. When working with multiple data frames, many operations, such as creating a legend, apply to the active frame The data frame that s currently active has a doited line around it and its name is bold in the table of contents Click a data frame on the map. using the Select tool, to make it active. Or, right-click the name in the table of contents and click Activate. Working with multiple data frames Multiple data frames are often used to display an area of interest in one frame and a reference map show ing the locatia of the area in another frame—in this case, the data frames have different map scales and extents. Multiple data frames are also used to show different views of the same geographic area—in this case, the data frames have the same scale and extent. Add new data frames to a map from the Insert menu. A quick way to make a map showing different views of the same area is to copy and paste a data frame, then modify how the data is displayed in each frame. 310 311 Using ArcGIS Desktop Using map templates Once vou compose your map, you can save the layout as a template. Thafs useful if you make sets of maps showmg the fame STfS«^ «ch as a book of parcel maps for a city. The template stores the layout (da, frame Zngemem map elements, and so on) as well as any data layers on the map (so your template can include ba e layers vTwCTioS map). When you star, a new map by opening a template. ArcMap reproduces the template L aLw ma^ocument Z keeps the original template document intact Map templates have a file ex.enston of .mtt«o distinguish them from map documents (.mxd). 1 Select Save As an the File menu.... iM«rjsMM ~ -Bad- ....then specify ArcMap Template as the file type. '.9 _QJ*-ft:ff" —jtr-3 » i i A- >--i--i.■ ArcMap also provides a number of standard map templates. You can select one of these when you open a new map. When you open a new map you have a choice of predefined templates. 4 • Mapping and Visualization Adding and arranging map elements Map elements explain the information on your map to the map reader. They can also make the map easier to read. The goal in adding and arranging map elements is to create a map that's attractive and easy to understand. Too much information or too many boxes and other elements just obscures the information you're trying to convey. Map elements are essentially graphic objects—some more complex than others—so they can be moved and re-sized like any other graphics. You can modify how they're drawn using the properties dialog box for the element or—in some cases—using the tools on the Draw toolbar. Titles, text, and neatlines are simply graphics. Legends, scalebars, and north ypywfl—while composed of graphic objects—arc derived from the geographic data in the data frame. Any changes to the data that is displayed will be reflected in these map elements. Map elements are added to the page in layout view, using the Insert menu. Map elements are added from the Insert menu. Adding titles, text, and legends Titles and text appear on the layout as soon as you choose the option on the Insert menu. You can then modify the text using the tools on the Draw toolbar. If wizards are enabled in your ArcGIS installation, the Legend Wizard will appear when you insert a legend (to enable wizards, click the Tools menu, click Options, and—on the General tab—check the box to turn Wizard Mode on). The wizard steps you through setting up the legend. Otherwise, a default legend will appear on the layout immediately, and you can use the Properties option to change its settings (right-click the legend). -Titles appear by default as the rr,Biier Layout name of the map file, centered at the top of the page. To modify titles or text, type in m the box. then press Enter. Drag B the text to move it: use the Draw toolbar to change the font size. - **B.... The legend content comes from the table of contents—layers that are currently displayed on the map appear in the legend; to change the name of a layer in the legend, rename it in the table of contents. To resize a legend, drag one of its handles, or change the text size on the Draw toolbar. 313 Using ArcGIS Desktop 4 • Mapping and Visualization Adding scalebars, north arrows, and neatlines When you insert a scalebar. scale text, north arrow, or neatline from the Insert menu, a symbol selector dialog box appears. When you select the element you want and click OK., it's added to the page. As with any other symbol you can customize north arrows and scalebars (click the Properties button on the dialog box). jua =31 a pii3-. (—53 • Greenvalley Rood Hazard When you insert any of these elements, a dialog box or symbol selector appears—select the symbol you want and click OK to add it to the map page. If your map has more than one data frame, when you add a scalebar or north arrow that map element relates to the active data frame (different data frames on a single map can have different scales and orientations). The Insert menu also lets you add picture files, such as a photo, a scanned image, or a bitmap logo, or embedded objects, such as a Microsoft Word document. You can double-click the object to open its application—any changes to the object are automatically reflected on the map page. Modifying map elements Click and drag an element to move it; use the handles to re-size an element. Right-click any selected element to display its Properties dialog box. You can also use the tools on the Draw toolbar to modify the selected element—select a neatline or box and use the Draw tools to change the fill or outline. Right-click any map element and select Properties to modify the element or set an explicit positron or size. r^n °- i_i Aligning elements To align elements, select the elements, then use the Align option on the Drawing menu. Or right-click the selected elements and use the options on the menu that appears. Select one or more elements, then right-click a selected element to access the options, or open the Drawing menu to access the s ime options 314 315 Using ArcGIS Desktop 4 • Mapping and Visualization Using grids and guidelines You can set up a grid or guidelines to make sure elements line up. You can use these purely as visual aids, or have the elements snap to the grid, guidelines, or the ruler. aaaooDQB »]s~3 Baa □ i* a • »> T7^ Click the ruler to set a guide. Drag the arrow to move the guide; right-click the arrow to clear it. Right-click anywhere on the layout to access guide, ruler, and grid options, including snapping. Rata I CM9 | 1 tm Ol CcrmrU , niiulriDnnniM II ~3 ■ I n A- »-J.- A- .|5JTT Navigating the layout As you work with the map elements, you'll likely want to zoom in and out, and pan across the page. Use the special page navigation tools—rather than the data navigation tools—when moving around the page. These are located on the Layout toolbar. •loua ■ 111 it* -1— r -3FT3 . / 'U4 P • L/se the Zoom Page too/ to zoom vi on the layout page (as opposed to zooming a^is^Tj s*m*»i in on the map data in the data frame). ***** k * ' " \~> 1 :>. f- • □ « ---TP Legend • Public buildings Streets Flood zone Parks J3 316 Using draft mode Draft mode displays the map elements (except for text) as empty boxes containing the name of the element, so the display refreshes faster. Using draft mode for arranging elements may be easier and faster—at least for an initial layout—especially if your map is complex. Draft mode also provides a schematic view of your layout. Right-click anywhere on the layout to toggle to draft mode (or use the Toggle Draft Mode button on the Layout toolbar) - Toggle Onsft Mode 317 Using ArcGIS Desktop Creating a graph Graphs are created from within ArcMap. and are derived from values stored in a layer's attribute table (or other table that has been added to the map). Graphs provide a visual summary of attribute values and can add useful information to your map. Using the Graph Wizard to create a graph Create a new graph from the Tools menu or open a table and use the Options button. Graph of park area «00.000- 350.000 ■ £ 300.000 -3 250,000- 3 2M.0O0- ■f 150,000- 100,000-50,000- 0.5 10 15 a O ■ ml The wizard lets you specify the type of graph, the field values to include, and graph elements such as title and legend. When you're done, the graph appears in its own window. 4 • Mapping and Visualization Adding a graph to a layout Once you've created a graph, you can add it to your map layout (you can also print, save, or export the graph to a graphics file). Access these options by right-clicking the graph window title bar. 3 -■*«-■» n v_ l . r . i" . r*. <* . f . r* . i' . i* I Right-click the graph window title bar and click Add to Layout. This menu is also where you print, save or export the graph. L, Graph ol park area 1j HO.SCfl j You can move and resize the graph just like any other map element. Modifying a graph To modify an existing graph, right-click the graph window title bar and select Properties, or Advanced Properties. ■- .......' 1 r*p~^~ lifciWI [«.. 31««. A MP* - ■MMin r mum ídor .... ■. ^ «1 Moll* 1 * t c— 1 1 select Properties, or Advanced Properties. m Sraph of park area Pnrt. 4100,000- Capy «*>■*«: J? 300,000- AtttULWfef Ef 250,000- "i 200,000-1 150,000-100.000-50,000- fmort... 0 5 16 » 1 Use Advanced Properties to access all the properties of the graph. Properties is the same as the Graph Wizard, only presented as a dialog box with two tabs. 318 319 Using ArcGIS Desktop Managing graphs The Graph Manager lets you access the graphs associated with a map. Click Tools, point to Graphs, and click Manage. ■ i ML. Con* Graf* *ddtet*rwt Right-click a graph in the list to access the management options, including open, print, and export. dmT Sm... MM- 320 4 • Mapping and Visualization Creating a report Reports in ArcMap let you list—and optionally summarize—data contained in tables. As with graphs, they are derived from the fields in a layer's attribute table or other table that has been added to a map. ArcGIS Desktop also includes Crystal Reports" for creating presentation-quality reports. Creating a basic report in ArcMap The basic process for creating a report is to specify fields to include from a table, using the Fields tab on the Report properties dialog box. Access the Report Properties dialog box from either the Tools menu or from a table's Options menu._ r -J. <.<*. 1 ( 1 ■ '' I-; tmirrr,,,. f »1 4Mp|u»til S ~3 Seteci* ffte toyer 6r teb/e, tfie/7 use arrow iVeys to move the fields you want to include to the right column. I Eft Le» s* frw ft ^ When you c/jcA Generate Report, the report is displayed in the Report Viewer window. Name Maintenance Stinjif \rrii Alder City 734 B4 .36915 Birch Oly 34471J21373 University City 77210.771434 FoottflE City 27331.15 0*9 Cherry aty 14W.733144 undeveloped aty 1 »9.122439 undevdoptd aty 11 ».3194 87 Dogwood City B&S.03369 Foresight Cits 17377.921397 Elm City 37024.207SB3 Lottgvien aty 71309J1O73 Irii City 125443.6J3B29 Bill top aty 217W 1.309323 Greenhills c% 437331.817073 Juniper City t514» 910654 undeveloped City 15 B82 BOOB 152 321 Using ArcGiS Desktop Once the report is generated, you can print or export the report, or add it to your map layout. On the Report Viewer you can print the report, export n to PDF or text, or add it to your map. Name Shape Art* Aider ary 73484.56915 Birch Oty 34471321375 Uiivcnily aty 77Z 10.771434 Footfall aty 27331.25049 i"hen} Oty 14961.733144 undeveloped 09 1289.122439 undeveloped Cíly 1123 519487 Dogwood aty 886.05369 FortnaM aty .7377.921397 fln aty 37024.207883 Longyiew City 71309.318373 bis esy 128443 B33829 Hilltop aty 217061.309323 OreeohUis ary 437531.117073 Juniper Oty 61469.920854 undeveloped ary 15 E82S.008152 When you add the report the view switches to Layout View (if you're not already there). Once the report appears on the layout, you can move and resize it just like any other map element. Use the tabs on the Report Properties dialog box to customize the report. 322 4 ■ Mapping and Visualization This tab lets you group sections of the report by category Choose a field containing the category values. Title-Group Title - Summary You can sort any of the fields. Click this button at any point to expand the dialog box window and see a preview of the report You can continue setting parameters, but you'll need to dick the Update button on the preview panel to see the changes Numeric values can be summarized. Haai 1111 Vrrj ,4 r, ah art 1IMO.i5 Umnay c-y T7J10.73 Aido C*j a* 611(W M c% row» ._,tv Mr; i.« 0» 17J3IJI FOCBH* c% ITITT.Í* ' 1"" c*. l«IB ■wkitiopcd • * 11X3 i ■ Dogwood Oř mar Shw.lte. CM B inu CMMCJ anui roun 7LW9J3 Update Settings The Display tab is where you set the parameters for how the report will look Click in a Value box to change a setting. Change colors and fonts clicking the button at the right side. a k-~ , ■■ llfttllllll in taaai--- ■IDIHHH 323 Using ArcGIS Desktop 4 • Mapping and Visualization Using Crystal Reports The report tool included with ArcMap is meant for creating basic reports that can be added to a map layout. You can optionally install Crystal Reports for creating presentation-quality reports (however these reports exist as files outside ArcMap and can"t be added to a map layout). The Crystal Reports wizard (if installed) is available from the Reports option on the Tools menu in ArcMap. Creating relief maps and perspective views Shaded relief maps and perspective views are useful for visualizing features that have height above or depth below the earth's surface. The tools to create these maps and views are included in the ArcGIS Spatial Analyst and ArcGIS 3D Analyst extension products. Creating a shaded relief map Shaded relief maps are usually derived from raster elevation surfaces, such as a digital elevation model. You create a hillshade view from the surface using tools in the Spatial Analyst or 3D Analyst extensions (available via Arc Toolbox). The appearance of the hillshade layer depends on settings such as azimuth, altitude, and z-factor (the Hillshade tool provides default settings). You then display other layers on top of the hillshade—the classic shaded relief map uses an elevation layer symbolized using a color ramp and displayed using a transparency setting. 324 - MM d ? COftSJ f Ccrtou Lst ^ CurvKura /> niw p OfcwrrtfftJ ? SDH * J '1 t.r» Use the ArcToolbox Hitishede tool to create a relief map from the elevation surface. □ * B • e * Jm^p j -j, * □ tff Then display the elevation surface on top of the hillshade, using a transparency setting—right-click the elevation surface 3] in the table of contents, select Properties, and click the Display tab on the Layer \ Properties dialog box. Cvtm | c $ »■**■« | 0 * .1—5»- 3 >iiA'>-J'. ~»~l c— I_I Set transparency here. 325 Using ArcGIS Desktop Creating a perspective view Perspective views are created in the ArcScene application provided with the 3D Analyst extension (available from the ArcGIS program group on the Start menu, if 3D Analyst is installed). You add datasets to a blank scene, similar to creating a map in ArcMap. To add a third dimension to the display, you specify an attribute associated with each feature that can be used as (or to calculate) a height or depth for the feature (known as a z value). Z can be a height or depth measurement—such as an elevation on the earth's surface, the height of a building, or the depth of a pipeline—or it can be a quantity, such as the population of each county. Terrain views require an elevation surface, upon which other layers can be draped. These additional layers don't require z values—rather their elevations are established with reference to the underlying elevation surface. When creating the view, you choose the viewer's angle and altitude, as well as the vertical exaggeration and illumination (3D Analyst provides default settings). Once you've created the initial view, you can navigate by panning, rotating and changing the altitude, and zooming in or out, to create the view you want. Open the Scene Properties to set parameters for the perspective view, including vertical exaggeration to make the difference in elevations more apparent. 4 • Mapping and Visualization You can create 3D maps by extruding features, such as counties extruded by population or building footprints extruded using building height. The attribute values are used as relative heights in the view. You can also combine perspective views with extruded features (to show buildings on a hillside, for example). Open the Layer Properties for the elevation surface (by double-clicking the layer name), and specify the elevation layer as the one from which to obtain heights (on the Base Heights tab). Open the Layer Properties for the layer you want to drape and specify-on the Base Heights tab—the elevation layer as the one from which to obtain heights. mm "' i To extrude features open the Layer Properties dialog box and—on the Extrusion tab—make sure the box at the top is checked. Then enter the field name in the box. Or click the Calculator button to open the Expression Builder and pick a Held name or create an expression. Specify an offset to slightly raise draped features above the surface end make them easier to see. 326 327 Using ArcGIS Desktop 4 • Mapping and Visualization Creating dynamic views and animations Dynamic views and animations are great presentation tools—especially when presenting geographic information to audiences not used to working with complex maps. Globe views are useful for providing context for your area of interest, as well as for presenting global geographic phenomena. The ArcGIS 3D Analyst extension contains two applications that let you create dynamic views and animations—ArcScene and ArcGlobe. Both applications are available from the ArcGIS program group on the Start menu, if the 3D Analyst extension is installed. You can also create animated maps in ArcMap to show a changing view of your data. Navigating ArcScene and ArcGlobe Once you've created a view in ArcScene (see "Creating relief maps and perspective views'), use the Navigate button to change the viewing angle and altitude, or use the Fly Over tool to move continuously through the scene. Navigate Fly/Walk over Toggle Globe/Surface Mode Navigate Fly over - ~ ..... 0» The Navigate button lets you change the viewing angle and altitude—hold down the leň mouse button, and drag the cursor. In fly mode, click anywhere on the scene to start moving; left-click to speed up, right-click to slow down. The Fly speed indicator in the lower left corner of the window gives you a reference In ArcGlobe, a shaded relief image of the earth's surface appears by default when you first open the application. The additional layers you place on the globe can cover any geographic extent—they don't have to be global. ArcGlobe has two navigation modes you toggle between. In globe mode the navigation tools let you spin the globe to view different portions of the earth's surface. In surface mode, you navigate across the surface, similar to navigating a view in ArcScene. ArcGlobe also lets you walk through the landscape, as well as fly over it. Globe mode lets you spin (he globe. IHUS-B-PEr Surface mode lets you travel over the surface. Capturing a navigation path as an animation ArcScene and ArcGlobe let you record the path of your navigation and play it back as an animation. You do this using the Animation toolbar (click the View menu, then select Toolbars and select Animation). Press Record, then start navigating through the scene as described above. The navigation is recorded as you move through the view or spin the globe. Press the Escape button on the keyboard to stop navigating, then click the Stop button on the Animation Controls to stop recording. Click Play to replay the animation. 328 329 Using ArcGIS Desktop 4 • Mapping and Visualization Creating an animation by capturing individual views You can use the Animation toolbar to create an animation in ArcMap. ArcScene. or ArcGlobe by capturing a "snapshot" of each static view (the map. scene, or globe view) in a sequence (these are known as keyframes). You then play back the captured frames—the interim frames are automatically filled in to create an animation. You'd use this method to animate panning across or zooming into a map. Capture a map. ■ ■ J. * ■ ml !•%« 3^ Use «?e navigation toots to set up a scene, then click Capture on the Animation toolbar to create a keyframe. When you re done capturing frames, use Play on the Animation Controls toolbar to play the animation (zooming on a topographic map draped over a surface, in this example). You'd also use it to capture a series of static views in a scene or globe view (rather than capturing a navigation as described earlier), and then play them back. This would let you animate, for example, changing layers on a globe—from shaded relief, through country boundaries, to population density. You can also animate changes to the map, scene, or globe display—for example, you might gradually increase the transparency of one layer to reveal a layer beneath. To do this, you create the keyframes by setting the display parameters and then creating a frame. Click Create Keyframe on the Animation drop-down menu. Set the Type to Map Layer (ArcMap). Layer (ArcScene). or Globe Layer (ArcGlobe) and select the layer you'll be animating (the Source object). Then click New to create a new track. Set the layer properties for the first frame (for example, you might change the transparency or symbology in the Layer Properties dialog box), and enter a name for the frame. Then click Create. Change the layer settings, enter a name for the next frame, and click Create again. Repeat this process for each frame; click Close when you're done Use Create Keyframe to animate changes in the properties of a layer (such as symbology or transparency settings). Click the New button to create a new track: then change the layer display settings and name each keyframe before creating the frame. All the frames will be contained in the track. When you play the animation, the interim frames are created. In this example, the transparency of the elevation layer increases to reveal the hillshade layer beneath, creating a shaded relief map. To animate a sequence of layers, add the layers to the map and select Create Group Animation on the Animation dropdown menu. When you play the animation, the layers will display in sequence (from top to bottom in the table of contents). You'd do this, for example, to create an animation of the locations of different types of crimes in a city, by police beat. 1KB« » ■ - • ♦ F- ~3 u! W -3I3-3 • 1 a A- »• . Use Create Group Animation to animate a sequence of layers on your map. 330 331 Using ArcGIS Desktop Saving and modifying an animation The animation is only active during the current ArcMap, ArcScene, or ArcGlobe session, unless you save it. You can reload a saved animation to run in another session. Use the Animation Manager to edit animations (to remove unneeded keyframes, for example). You can also export an animation to a video file (.avi or .mov) that can be played in other software programs. .- y m * ■ tit*- nr H-fr ■f - ] r Via-at ai-.i-i-igwi-jra.-n> Use Me sJ/der on the Animation Manager Time View tab to play the animation. Or open the Animation Controls dialog box and use the Play button. 334 335 Using ArcGIS Desktop Creating an animation using Tracking Analyst The ArcGIS Tracking Analyst extension allows you to display temporal data dynamically or capture an animation. Tracking Analyst accepts a wide range of date/time formats. It also has advanced options for symbolizing temporal data, viewing animations, and interacting with temporal data (for example, it will capture a live data feed to track objects in real time). The Tracking Analyst—if enabled—is accessed from inside ArcMap, via the Tracking Analyst toolbar. You load a dataset containing a time element to create a temporal dataset using the Add Data button on the Tracking Analyst toolbar. «-[•'— ]mmt *rk . -mm * 1 - *l □ « - -* Use the Add button on the Tracking Analyst toolbar to open the Add Temporal Data Wizard. itfl>(rnZH ' ..." •bbbkal nrjfiH rBrjKCAi.SiOB.1 [flOP-fx. Df PW«JOH 'F«Pe*i.MPP£S5»0K "06-OV1«1SI»FB >>'•-•• " ■ • i. IlWM/lJB'i'tBK c&oayiwiaiaco oanvissc-torx" OMrVUKlBflOOD J_____Zt _ -4ny geographic data having a dale and/or time stamp can be used with Tracking Analyst. The wizard asks for the Held containing the date and time data, and the format it's in. ■i-i-i - W W| 4 1 ■ I ► | W] r Lota ■ -I- fmm Ottmtm "~3 F» ffw Once a temporal layer has been added, use the Playback Manager to run the animation. 336 4 ' Mapping and Visualization There are a number of options for displaying the data—you can animate the time series, drag the red bar to manually step through the frames, or pick a specific date from the calendar to see the conditions on that day and time. jutfj The Symbology tab on the Layer Properties dialog box lets you control the display —for example, color code crimes by police beat. Drag the red bar to step through time, or use the playback controls. Use the calendar to see the conditions on a specific date. The Symbology tab also lets you control the time-based display—for example, whether features stay on the map as the animation plays, or only appear during a brief time window. Use the Animation tool to create and save an animation. Animations are saved as a movie file that can be played using any media player. ■araaBBBaTBBTW'. jLs. !___ . J Open Animation Tool from the Tracking Analyst toolbar to generate an animation and save it as a movie file that can be played in any media player. 337 Geographic Analysis An overview of analysis in ArcGIS Desktop • 340 Working with tabular data • 348 Exploring tables in ArcMap Exploring tabular data in ArcCatalog ArcToolbox tools for working with tabular data Adding fields and calculating attribute values • 352 Using ArcMap to add a field and calculate values Using ArcCatalog to modify a table ArcToolbox tools for working with fields Joining tables • 355 Appending tables using a common field Relating tables using a common field Appending tables using spatial relationships Selecting a subset of features • 360 Selecting features interactively Selecting using feature geography Selecting using feature attributes Specifying the selection method Working with a selected set • 365 Saving the selection Exporting the selection Other places the selected set is active Extracting a portion of a dataset • 369 Cropping feature datasets Splitting feature datasets Extracting raster data Sampling raster data Overlaying geographic datasets • 373 Overlaying feature datasets Overlaying raster datasets Measuring distances between features • 379 Measuring distance on a map Calculating distance between features Buffering features Calculating distance over a surface • 383 Creating paths and corridors • 386 Modeling a path over a surface Modeling a path over a network Allocating areas to centers • 391 Creating areas around centers Creating service areas using a network Modeling flow • 395 Modeling flow over a network Modeling flow over a surface Creating raster surfaces • 398 Creating an interpolated surface Creating a density surface Creating a TIN surface • 402 Deriving data from an elevation surface • 404 Calculating surface volume • 409 Analyzing visibility • 412 Measuring line of sight Creating a viewshed Measuring solar radiation ^ Analyzing spatial distributions • 416 Calculating the center and dispersion Analyzing directional trends Identifying patterns and clusters • 419 Using ArcGIS Desktop 5 • Geographic Analysis An overview of analysis in ArcGIS Desktop Types of GIS analysis GIS analysis covers a wide range of tasks and applications, from simply calculating values for a new field in a table, to modeling complex processes such as the flow of water over terrain or using statistics to perform spatial pattern analysis. The ultimate goal of analysis is to get more information from your data to make better decisions. ArcGIS Desktop lets you perform geographic and spatial analyses on a variety of datasets: tables, feature classes, rasters, terrains, TfNs. network datasets. and geometric networks. The tools to perform these analyses are found in several toolboxes in ArcToolbox, as well as on specialized toolbars in ArcMap and in several ArcGIS Desktop extension products— ArcGIS Spatial Analyst, ArcGIS 3D Analyst, and ArcGIS Nctw ork Analyst. The GIS analysis functions in ArcGIS Desktop can be grouped into several fundamental types of operations: tabular analysis, data extraction, overlay analysis, distance analysis, surface creation and analysis, and statistical analysis. Tabular analysis Tabular analysis includes basic functions such as sorting or finding the frequency of values, modifying tables by adding and calculating new fields, and establishing and managing relationships between tables. Calculating a frequency distribution of values is an example of basic tabular y o^t, fm analysis. Data extraction Data extraction is a component of most analyses. It includes extracting a subset of features for analysis or clipping a study area out of a larger dataset, as well as dissolving or generalizing to create fewer, larger features from many small ones. 340 Parcels that fall completely or partially the Hood zone have been selected and as a new layer. Using ArcGIS Desktop 5 • Geographic Analysis Distance analysis ArcGIS Desktop includes a variety of distance analysis functions that allow you to measure the distance between features, find the features within a given distance of other features (buffer), create a continuous surface of distances from a set of features (such as distance from roads or streams), or find the optimum path over a network of linear features (streets or pipelines) or over terrain. A buffer of streams A surface of distance from streams The shortest path between three stops on a street network Surface creation and analysis Surface creation functions let you create a surface of spatially continuous values from a set of sample measurements or observations {interpolation, or density), or create derived layers from a surface (slope, aspect, contours, or a hillshade view). Surface analysis functions include specialized tools for predicting the flow and dispersion of water or other materials over a surface, calculating volumes (such as cut and fill), performing visibility analysis, or calculating the amount of solar radiation received at each location. q 9 O O O A continuous surface created from a set of sample point values. A surface of road density—darker orange indicates higher density Line-of-sight analysis—green indicates areas visible from the observer point. Statistical analysis Statistical analysis ranges from tabular statistics, such as finding the mean or standard deviation of a set of values in a table, to functions that measure the characteristics of a distribution of geographic features (such as the center or directional trend), to spatial statistical tools that identify patterns formed by features (or their associated attribute values) and let you detennine the probability the pattern did not occur by chance. ^■Ja^jji mm* -'f TirrarT- Summary statistics have been calculated for each ianduse class showing the number of parcels in that class, the size of the smallest and largest parcel, the average parcel size, and the total area in the class. The standard deviational ellipse for burglanes (showing the directional trend} 2"v\ The map on the right shows statistically significant clusters of census tracts with many senior citizens (orange) or few (blue), calculated from the percentage of seniors in each tract (shown in the map on the left). 342 343 Using ArcGIS Desktop ArcGIS Desktop ArcGIS Desktop provides a range of tools to perform analysis operations. The tools analysis tools described in this chapter are some of the most commonly used—there are many more tools available. Many of the tools are generic and can be applied to any application or industry. Some are more application specific (such as functions for analyzing groundwate: movement). Most tools for analyzing vector (feature) data are provided with ArcGIS Desktop (if you have an Arclnfo license). Most tools for analyzing surfaces (rasters and TINs) are included in several different ArcGIS Desktop extension products. Tools for analyzing features ArcMap functions for analyzing feature data include tabular analysis, available from the menus associated with table views, and some data extraction functions, available from t Selection menu. ArcToolbox functions include tabular analysis, data extraction, feature overlay analysis, feature distance analysis, and statistical analysis. The Utility Network Analyst toolbar—included in ArcMap—allows you to trace flow over electric, water, or other utility networks. You can trace upstream or downstream, find loops, find connected features, and so on. Network Analyst, an extension product, provides functionality for distance anal\ sis along connected linear features such as in transportation networks. Tools for analyzing surfaces Three ArcGIS Desktop extension products—Spatial Analyst. 3D Analyst, and Geostatistical Analyst—provide tools for creating and analyzing surfaces. While they include some overlapping functionality, they were each developed to meet the needs of analysts requiring specific capabilities for their application. Spatial Analyst includes tools for analyzing the relationships between rasters. These can be rasters representing surfaces of continuous values (such as elevation, slope, temperature, or precipitation), or rasters representing contiguous areas (such as soil types, vegetation types, land cover, or geology). Along with tools for managing and processing rasters. Spatial Analyst includes functions for raster data extraction, overlay analysis, and distance analysis, as well as for surface creation and analysis. 3D Analyst provides functionality for surface creation and analysis. 3D Analyst also includes visualization tools for creating perspective and globe views (see 'Creating relief maps and perspective views' and 'Creating dynamic views and animations' in Chapter 4). Geostatistical Analyst provides advanced functionality for creating continuous surfaces from a set of sample points. It also includes tools for interactive data exploration to aid in the selection of appropriate interpolation parameters. These are accessed from the Geostatistical Analyst toolbar in ArcMap. The Geostatistical Analyst toolbox (in ArcToolbox) contains a set of geostatistics tools that can be used in scripts or models. 5 • Geographic Analysis This table summarizes some common types of GIS analysis and where the specific functionality is located in ArcGIS Desktop. ArcMap ArcToolbox Tools Network Analyst Extension Spatial Analyst Extension 3D Analyst Extension Geostatistical Analyst Extension Tabular Analysis Sort field Summarize by other field(s) Field summary statistics Value frequency Field summary statistics Data Extraction Interactive feature selection Select features by attribute Select features by location Clip/Split features Update features Select features by attribute Extract raster cells by attribute or geometry Extract raster cell values to point features Overlay Analysis Feature overlay Combine rasters Raster overlay Cross-tabulated areas Distance Analysis Measure distance tool Select features within distance Utility network trace Buffer features Point-to-feature distance Allocation Shortest/ Least-cost path and allocation over a transportation network Euclidean and cost distance Shortest and least-cost path and allocation over a surface Surface Creation and Analysis Surface interpolation Surface density Surface analysis Surface interpolation TIN creation Surface analysis 3D visualization Advanced surface interpolation (kriging) Predictive surfaces Statistical Analysis Geographic center/ dispersion Pattern/Cluster analysis Directional trend analysis Raster cell, neighborhood, zonal, and multivariate statistics Exploratory spatial data analysis 344 345 Using ArcGIS Desktop In many cases, you'll combine different types of analysis to perform more complex analyses. A suitability analysis, for example, may involve distance analysis and surface creation to generate input layers, data extraction to clip out the study area, tabular analysis to reclassify feature values, overlay analysis to combine layers, and data extraction to select polygons meeting the criteria and to dissolve the selected polygons to create the final areas. 5 • Geographic Analysis The GIS analysis process Hial >N«I*I Gnatcatcher Habitat Suitability An example of a suitability model, built using the ModelBuilder interface Models and scripts are often used to automate the analysis process. You can easily change the parameters of the analysis by opening a tool in the model or editing the script. You can then rerun the analysis without having to run all the individual tools. Models and senpts are also a good w ay to document, store, and share your analysis methods. The underlying engine for analysis is geoprocessing. Broadly, geoprocessing involves applying a function, or set of functions, to existing data to get new data. Most of the geoprocessing functions in ArcGIS Desktop are provided through tools in ArcToolbox. Some functions appear as menu options in ArcMap. Accessing and using geoprocessing functions—including building models and scripts—is discussed in the section 'The ArcGIS Desktop framework' in Chapter 1. 346 GIS analysis is a process that follows a basic set of steps. The actual methods you use can be simple or complex, from selecting features having a given value to building a model to combine many layers of data. For simple methods, such as a selection to extract features from a dataset, you might intuitively implement the process as a single operation, rather than as distinct steps. Frame the question You start an analysis by figuring out what information you need. This is often in the form of a question. Where were most of the burglaries last month? How much forest is in each watershed? Which parcels are within 500 feet of this liquor store? Being as specific as possible about the question you're trying to answer will help you decide how to approach the analysis, which method to use. and how to present the results. Other factors that influence the analysis are how it will be used and who will use it. You might simply be exploring the data on your own to get a better understanding of how a place developed or how things behave; or you may need to present results—to policy makers or the public for discussion, for scientific review, or in a courtroom setting. In the latter cases, your methods need to be more rigorous, and the results more focused. Prepare your data The type of data and features you're working with helps determine the specific method you use (for example, your forest and watershed data might be stored as polygons, or rasters |. Conversely, if you need to use a specific method to get the level of information you require, you might need to obtain additional data. You have to know what you have (the type of features and attributes), and what you need to get or create. Creating new data may simply mean calculating new values in the data table or obtaining new layers. Understanding the data that goes into the analysis will help you interpret the results. Choose a method There are almost always two or three ways of getting the information you need. Often, one method is quicker and gives you more approximate information. Others may require more detailed data and more processing time and effort, but provide more exact results. For example, you can find parcels within 500 feet of a school as the crow flies—by simply creating a buffer—or within 500 feet walking along streets and paths (a more involved network analysis). You decide which method to use based on your original question and how the results of the analysis will be used. Process the data Once you've selected a method, you perform the necessary steps in the GIS. This often involves running several functions in sequence. For example, to find the amount of forest in each watershed, you might extract the area of interest from the forest layer, convert it from raster to polygons, overlay it with the watershed boundaries, then do tabular analysis to calculate the total forest in each watershed. In the case of statistical analysis, you'll also want to calculate the statistical significance of your initial results. Investigate and analyze the results Looking at and questioning the results help you decide whether the information is valid or useful, or whether you should rerun the analysis using different parameters or even a different method. GIS makes it relatively easy to make these changes and create new output. You can compare the results from different analyses and see which method provides the most accurate information. 347 Using ArcGIS Desktop Working with tabular data An important part of analysis is working with the data in tables. These can be standalone tables, or attribute tables associated with feature or raster data. You may want information about the values in a table for its own sake or in preparation for other analysis. For example, you'd want to identify any outliers (extreme high or low values) before creating a surface or performing pattern analysis, since outliers can skew the results of your analysis. Exploring tables in ArcMap To sort a field or summarize the values by another field, open the table in ArcMap and right-click the field name. 5 • Geographic Analysis Right-click a layer name and select Open Attribute Table. The Summarize dialog box lets you get summary statistics for one field by other fields—for example, total area of each landuse type. The results are saved in a new table and added to the map. Rtght-click the summary table name in the table of contents (using the Source tab) and click Open to display it. Right-clicking a field name in the table window in ArcMap also allows you to calculate summary statistics for the field—such as the minimum and maximum values, the mean value, and so on. The results are displayed in a window that also includes a histogram showing the distribution of values. The Statistics window gives you infomnation about the distnbution of values. When you open a table, by default ArcMap includes all the fields, with the values in their original data formats. To specify which fields to display in the table window, to assign an alternate name (alias), and to format data values (to show fewer decimal places, for example), use the Fields tab in the Layer Properties dialog box. 348 Use the Fields tab on the Layer Properties dialog box to specify which fields to display in the table, and to create an alias for the field name. - O-Pta. ü^eofc» F_, (B_^a_,|L__|j— lINfeMl MSI.lWTTS HSE.UWTS VOCMft VACMH OtaWtRJXX OVW^KC KNTCR.OCC REMTEfl.OCC H0JMmt.1t HO.MfWSS? txpjatv atop jam «Vfi.SALESJ gy^Hug Click the box with ellipses to format numeric values—this changes only the display, not the actual stored values. Type in here to create an alias. 349 Using ArcGIS Desktop You can also hide a field by right-clicking the column heading and clicking Turn Field Oft". ISMTl.FWSlOIlT flWl n« fc.------' * £'- ■ It jg- — nfi? 5SC1' It , * Oil IDS SB ' irJW'lW 37 It-- ZjSB_I SMS 6968 31311 3786 si es f"------ * m* <™™* !™'"*' J ftaca* paJMQI null HWj a (a£/e open. right-click a column heading to hide that Held. 5 • Geographic Analysis Use the Options button on the table window to set the font type and size for the entire table—click Appearance on the menu, then change the settings in the Table Appearance dialog box. Change the text font and size of an individual table from the table's Options menu. Use the Options settings on the Tools menu to specify the appearance of all tables in the map document. Tabular data can be displayed graphically in ArcMap using graphs. Graphs present a visual summary of attribute values ArcMap also lets you create a finished report from tabular data. Graphs and reports can be printed or added to a map layout. See 'Creating a graph' and 'Creating a report' in Chapter 4. Exploring tabular data in ArcCatalog You can also sort fields and get summary statistics in ArcCatalog. using the Preview tab. This is a quick way to get a sense of the distribution of values. ■nmi.il. ii.I.ii... I .i.i mi... i . . in I. II. II .1.1 J« rr Right-click a field name in table preview mode to access sorting and statistics options. ArcToolbox tools for working with tabular data ArcToolbox includes tools for calculating summary statistics and a frequency table for a field. The results are written to tables you can add to a map or preview in ArcCatalog. Having the information in a table is useful if you need to save the information or use it in additional analysis. The tools are useful for including in models and scripts. □ Mr □ no □ •HE* Q: i" Li ■ '. I ■tToohn h 30 »*r« to* h Ctl'^CfS^rt Tools ■ CmvfrfHn Tort w ! iivr ay. loofe SGeaUOItXm Andy* Took Unew R«s;era--a Tot* j FiwoitM I '"d» 1 Sow* | The Summary Statistics toot lets you specify which fields and statistics to include. The results are written to a record in a table. j nisi The Frequency toot calculates the number of occurrences of each value for the specified field, or unique combinations of values for multiple fields. You can optionally include summary fields—the result is similar to the Summarize option in ArcMap. "3-1 AREA anfj ■±l 211 ii ±1 I PC | minor|»J s—ij»t«««iuir'i«li 350 351 Using ArcGIS Desktop Adding fields and calculating attribute values Fields are usually added to attribute tables and populated with values when building a geodatabase. When performing analysis, though, you may find you need to add fields to a table and assign or calculate values. For example, you might reclassify detailed categories into general ones, or calculate percentages or densities from existing fields to map or use in your analysis. The usual process for this is to create a new field in the table and then calculate the new values for the field. In some cases—such as when reclassifying categories—you'll select subsets of features before calculating values. Using ArcMap to add a field and calculate values You'll likely be working in ArcMap to perform your analysis. To add a field, open the table, click Options, and click Add Field. Right-click the column heading for the newly added field to calculate values for the field. it; Hh |Ptrl_ViC*NT| Specify the field name, type, and properties. Use the Options menu on the table window to add a Held. I rihteh oclNO ^N5s^ *.vc_s_i?r£nnp_».rji3r' jv__~_iir.;" Right-click the field name and select Field Calculator; then use the calculator to build the expression. HOUSDOM -1 a HJMI H«_£s " r oat MtfHH DO tWMH HQ r. ••• - - J MED *&. I uuLt.R&a _j *fl 1 _ Catl) | e^pi i 1 _ii J - 1 «• 1 =—' J •... ^- H-. •. I| 5 • Geographic Analysis When you calculate values, you'll get this warning, unless you're in an edit session. n bogrtt Do you *ah lo eortruTV If you calculate values outside an edit session, you can't revert to the previous values for that field (you can always renin the calculation and overwrite the values you just calculated). The advantage of calculating values in an edit session is that you can undo the calculation if necessary, using the Undo button on the Edit menu. You can't, however, add or delete fields while you're in an edit session—you'll need to add the field before starting the session. Editing a table also allows you to assign values to features individually (using the Edit Table button on the Editor toolbar). See •Starting and managing and edit session' and "Adding and editing attribute data' in Chapter 3. To edit a table in an edit session, click the Edit button lo open the Editor toolbar, then select Start Editing from the dropdown menu. Calculating values inside an edit session is the same as outside except that the Undo button rs available on the Edit menu. 352 353 Using ArcGiS Desktop Using ArcCatalog to modify a table ArcCaialog also allows you to add fields to a table and calculate values, in the table preview window. You'd use ArcCatalog for this if you were reviewing and preparing your datasets prior to performing analysis in ArcMap and know there arc certain fields you will need. If a layer is already open in ArcMap. you can't add or delete fields in ArcCatalog (a warning message is displayed). The reverse is also true. Use the Options button in the table preview window to add a field. ArcToolbox tools for working with fields ArcToolbox contains tools for adding and deleting fields in a table, calculating values, and setting a default value for a new field. The parameters are the same as for creating fields and calculating values using ArcMap or ArcCatalog. The ArcToolbox tools are particularly useful when you're working with tables in a script or model. f Add Fiat! ^ *«-7i 0«f«* To HaB § Cabiete End Data f CrtoJtteReU f Mete Rett & Trerrema Tmt Ftddi j J_ _i jT Tools for working with fields can be found in the Fields toolset, located in the Data Management toolbox. joining tables Often in analysis you'll need to join the attributes contained in two separate tables. You'd do this when assigning the attributes in a standalone table to geographic features so you can map or analyze the features using the additional attributes. For example, you may want to join health statistics for a set of counties, stored in a standalone table, to the attribute table for a map layer of counties. You join the tables using a field they have in common, such as county name. You can then display the counties symbolized by the values for a particular statistic, such as the number of flu cases in each. Another type of join—a spatial join—is used to join the tables of two map layers using the spatial relationship between features. Spatial join lets you, for example, assign demographic attributes to stores (point features) based on the census tract (polygon) they fall within. Appending tables using a common field Join appends the joined attributes to the original table for as long as the join is established (use Remove Join to delete the join) If you export the new layer to a dataset. the joined attributes will be saved in the dataset's attribute table. Join can be used with one-to-one or many-to-one relationships (see 'Building relationships between features and tables' in Chapter 2 for a discussion of types of tabular relationships). 354 5 • Geographic Analysis 355 Using ArcGIS Desktop Once the tables are joined, you can use the appended attributes anywhere you access attribute values—for example, to symbolize features (see 'Using attributes to symbolize features' in Chapter 4). The fields in the joined table are listed in the Fields dropdown list on the Symbology tab. urn To permanently save the appended attributes in a single table, export the layer to a new dataset. 3 U Aaa «T i~ ISl 7b save the joined attributes \permanentfy in a new table, point I io Data and dick Export Data. Use the Joins & Relates tab on the Layer Properties dialog box to manage all joins you've established for the layer. 5* Geographic Analysis To join tables within a script or model, use the ArcToolbox Add Join tool. In this case, the join is in effect only for the duration of the ArcMap or ArcCatalog session. Add Join is also available as an ArcToolbox tool, in the Data Management toolbox. On,* - 1«. jj ^ Add Join -Wmi ■ <«■ *tw te ■ ktiw (or • IWX vrnmrntM Tin recant* Of *WA ujTf or Wot ■aw n nuicfiM io !h* nan =-. M |an tana *aw MM on tnt jot W4 and I ha Hpm Fata wnan ;ha «ttutt If* atjuat Tht join n tamsortrj |M it IM lajarg and aal s*#> im fe( ItH MtfJiop, ■■»VI _ «Im -- tflpll - 1 f IK 1 Canal J t— 1 H» | Relating tables using a common field Relate can be used with one-to-many or many-to-many relationships. Rather than appending the attributes. Relate only stores the relationship (or link) between the tables (it can't append the attributes to the original table since there may be many records in the related table pointing to a single record in the original table)—the related records are accessed on demand, when you select a feature or record in the original table. Relate is accessed by right-clicking a layer name. The relate is a link stored with the map—so in addition to specifying the related table and the common Field between the two tables, you specify a name for the relate. 356 357 Using ArcGIS Desktop 5 • Geographic Analysis * [ttsjti-g u To access the related table, select a feature I 3 - - m\_ (or features) in the layers attribute table. select Related Tables from the Options menu, and click the name of the relate. The corresponding records are selected in the related table—you can get statistics, summarize, or calculate values for those records. With both Join and Relate, the relationship is stored with the map. rather than in the database, so if you add the datasets to another map, the join or relate will not exist—you'll need to re-create it. If necessary, you can create relationships within your geodatabase that will persist from map to map (see 'Building relationships between features and tables' in Chapter 2). Appending tables using spatial relationships Spatial join allows you to assign the attributes from one set of features to another, based on the spatial relationship between the features—fully contained within, intersecting, or within a distance. The type of relationship available for the join depends on the types of data you're joining. The attributes of the joined dataset are appended to the table of the input dataset, and saved as a new dataset that is added to the map. One reason to do a spatial join is simply to add an attribute to a feature, such as adding the county name (in a polygon layer of county boundaries) to auto accidents (points). Another is to be able to summarize the data, such as summarizing the number of accidents in each county. Spatial pin is accessed from the Join option—use the drop-down menu to specify pin based on spatial location. Attributes of features that meet the spatial criteria are pined. In this example, information about the parcel each building sits on has been added to the building layer's attribute table. 358 359 Using ArcGIS Desktop 5 • Geographic Analysis Selecting a subset of features Selection is used to extract a subset of existing features from a dataset. You'd select features to analyze the subset of features separately from the full dataset or to create a new dataset containing only the selected features. Selections are created by selecting features interactively on a map. by using features from other layers that overlap or are near the features you want to select, or by selecting features that match attribute values you specify. The selected set can be modified by adding to the selection, removing from it, switching it with the unselected set. and so on. Selecting features interactively Use the Select Features tool to select features interactively by pointing at them on a map in ArcMap. Click to select a single feature. Selected features are highlighted on the map and in the table. Click Show Selected to view only the selected features. Drag the tool to select features intersecting a rectangle. ■ -3 Drag to select adjacent features. By default, layers are selectable when added to a map, so if you have multiple layers on your map. when you point at a feature or drag to create a selection rectangle, all features at that location—from any of the layers—will be selected. You can work with the selected features for each layer separately; however, you may want to select features only from a specific layer, rather than all layers. To specify which layer(s) to select features from, use the Set Selectable Layers option on the Selection menu, or use the Selection tab at the bottom of the table of contents. If a layer is selectable, features will not be selected unless it is also currently displayed (it is checked on in the table of contents). Use Set Selectable Layers on the Selection menu to specify which layers features can be selected from. Use Options on the Selection menu to change the search tolerance, highlight color, and other settings The Selection lab at the bottom of the table of contents is another way of setting selectable layers. A default color is used to highlight selected features. Change the selection highlight color for an individual layer using the Layer Properties dialog box for that layer. ^m^m^m^m^m^mmmmmm.- jus I Sua |D^»| iiimw 1 F<é» i C**«iB—| t^| Jm.H>—»| e i III .......in i j. The Selection tab on the Layer Properties dialog box lets you specify a unique highlight symbol or color for an individual layer. 360 361 Using ArcGIS Desktop Selecting using feature geography Use the Select By Location option on the Selection menu in ArcMap to select features geographic relationship to features in another layer (to select parcels containing public Open the Select By Location dialog box from the Selection menu. in one layer based on their buildings, for example) The dialog box lets you specify the layer(s) to sefeci from, the spatial operator, and the layer to use to create the selection. lsr>.v>ews Hoke Fean/e Layer MakeCjuory latte Make Pastor Cotatifl. l*)* Make Raster Layer mbTasbVto* CT Cvant Layer iM loLayw He Bi Albbuto it-Kt IM« By Lotaoji and Iranjrwnwtlcra T^e Setecf Layer By Location tool in ArcToolbox (in the Data Management toolbox) performs the same function as Select By Location. Spatial operators—available from the drop-down list—include overlay, adjacency and distance. Selecting using feature attributes Another way of extracting a subset of features is to select them based on an attribute value, or combination of values. This approach is often used to select features that meet some criteria you've defined. You create a query statement using the field name. Boolean operators ("equal to." "greater than," and so on), and the attribute value. Open the box from The dialog box lets you build a SQL query using logical operators-choose fields from the top panel and choose values from the list in the middle-right panel. Your query statement is constructed in the lower panel (you can also enter explicit values here). Selecting using attributes is also available in ArcToolbox. The tool dialog boxes are similar to the ArcMap selection dialog boxes. The tools are useful for performing selections from within a script or model. g^T^,- «1 • t% X AnOrr* Tools g t% AisVsa -ocij - Emm Sttoit ^TatteSot* • Overiay 1 (% Canafttttf To* • % Corrrtradm Tone; I % "ove-ageToc* B % -*-** Haneg-jnont 1 oak * ^ Geacadno Took FtWHei | Inda. 1 Statthl The Extract toolset in the Analysis toolbox contains two tools for selecting using attribute values. Use Select for feature attribute tables; Table Select can be used for feature attribute or standalone tables. - 5^ sE- P r*eke Feature Lay-* > MlHQjdn Table y Make Barter CBtebjLayer /> Mgx Rafter Layer S> Moke Tat* Ve*. /nhintwtLwr >SavaroUy-H. ^ 5fSBrt Lay« By «trfcvt? ^ Select Lorer By Location - tj) ProjeTOonf antf Trantforeiat-jri* _jj ■Jeellnde. [ Search] 77w Setecf Layer By Attribute tool is in the Layers and Table Views toolset in the Data Management toolbox. 362 363 Using ArcGIS Desktop Specifying the selection method Once you've created a selected set. you can specify whether subsequent selections create a new selected set (the default), are added to the current set, removed from the set. or selected from the current set (to create a subset of the selection). For interactive selection using the Select Features tool, the Interactive Selection Method is set on the Selection menu. "3 j. *.«jn w _I. For selecting by location or attributes, the Method is set using drop-down menus on the dialog box. lid :c-----J 1 mvam | to la 5 • Geographic Analysis Working with a selected set Once you've created a selected set, options for working with and managing the set are available from the Selection menu in ArcMap and from the context menu for each layer for which there is an active selection. You can calculate summary statistics for the selected set—either from the Selection menu, or from the layer's attribute table (nght-click a field name). This option chars all selected features for all layers ST X> mi 366 Right-click a layer and use Export Data to save the selected features as a new dataset. Make sure the Export option is set to Selected features. 367 Using ArcGIS Desktop Other places the selected set is active The current selection is active throughout your ArcMap session, including when summarizing or calculating attribute values in a table, and when printing a map. Values can be calculated for selected features only. Ufa. ra —MCIEfl USEJ1ASS Cnl 1 E-| 1 r.t 1 L=Ol 1 -1 £l 1 J_J_J JJjJ t«~- r*»™ Wften summarizing values you have the option of using only selected features. [T'imi—ii—wriim." it ■ -tr l1 r~s~i 5 • Geographic Analysis Extracting a portion of a dataset Extraction uses an existing dataset, or geometry you define, to extract a portion of another dataset. Data extraction is used to clip data to a study area boundary, split a dataset into map sheets, or extract an area of interest for further analysis, such as when running a model for a portion of your study area. A new dataset is created containing the extracted data—the original dataset is not modified. Unlike data selection, which creates a temporary selected set, data extraction extracts data directly to a new dataset. Also unlike data selection, features are split or clipped where they are intersected by the geometry you're using for extraction. All of the data extraction tools are found within Arc Toolbox. Cropping feature datasets The Clip tool allows you to crop a dataset using the boundary of a polygon dataset. Features are split where they intersect the cropping boundary, and the portion outside is discarded. Clip is mainly used to crop datasets to a study area boundary for mapping or analysis. The Clip tool, in the Extract toolset (Analysis toolbox), crops datasets to a dataset boundary—in this example, roads, streams, and lakes have been clipped by the study_area dataset. 9> I. i- I— * « "3-1 1 -I » I —■ |. ~3 I A* J.- Selected features are active in Layout View and will be highlighted when you print a map □ 4 ii a f • as□ ocs - •!■ .lOUO a a a ■ ""HI-] » / a a- »--■ 368 The inverse of Clip is the Erase tool. Erase discards the features (or portions of features) within the boundary and is used to remove portions of a dataset. Erase, in the Overlay toolset (Analysis toolbox), features from the area inside the dataset boundary. 4 ArcToofaoz 3DAr>aVa Toob flnaVw'o* 369 Using ArcGIS Desktop 5 • Geographic Analysis Splitting feature datasets The Split tool divides a dataset into multiple datasets using polygon boundaries. It's often used to create map sheets from a single large dataset—a dataset of map sheet boundaries is used to split the dataset. The Extract by Attributes tool allows you to extract cells based on an attribute value, or combination of values. You create a query statement using the field name. Boolean operators ("equal to," "greater than," and so on), and the attribute value(s). This is useful if you need a subset of values for your analysis—for example, you may want to analyze [he relationship between vegetation and elevation for a certain elevation range. * * ■ *- j.' i- J. JJ ,N*„ j " ■ ~ - ' ' H A" -* The Split toot, in the Extract toolset (Analysis toolbox), breaks a dataset into multiple output datasets. The values in the Split Field are used to define and name the c datasets (in this example the two map sheets were named "north"and "south'). Extracting raster data Tools for extracting a portion of a raster dataset arc provided as part of the Spatial Analyst extension, The tools allow you to use an existing feature or raster dataset. or a shape you define (a rectangle, circle, or polygon), to extract a portion of the raster dataset. These tools are mainly used to create a subset of the dataset for use in a model (perhaps ft testing purposes) or other analysis, or to distribute to other GIS users. P fLstract by Mtrtutn Extract frcnfe ^ tOratt by Mas! ^ Ertroct by Pouts ^ Ejffaet by fVfgm £k /mm /t*«dV«L« £flj*t by »CTtoui« I.■■■>■:-< ft ^ Ejoact bt /• 1 chart tn Para j> Futioct by Hftrtan^e "3 a _*l I m ■ TTie Sample tool finds the values at each point tor a list of rasters you specify. It writes the values—along with the x- and y-coordinates of each point—directly to a table you can use in other analyses. The Extract Values to Points tool creates a new point feature dataset (containing all the input point features). It adds the value of the input raster at each point to the new datasefs attribute table. 5' Geographic Analysis Overlaying geographic datasets Overlay analysis merges two or more coincident or overlapping datasets to create a new dataset having the attributes of all the input datasets. Overlay analysis is used to assign the attributes of features in one dataset to features in a coincident dataset. for example, to assign the adjacent land cover type to each segment of road. Overlay is also used to summarize the data in one dataset by the features in another—to calculate the total area of each landuse type within a flood zone you'd overlay the parcel layer with the flood zone layer and then sum the areas of the resulting polygons by landuse type. Another common use of overlay analysis is to combine the characteristics of several datasets into one. You can then find specific locations or areas that have a certain set of attribute values—that is. match the criteria you specify. For example, you'd overlay layers of vegetation type, slope, soil type, and so on. to find areas suitable for building a new subdivision. The type of data you're overlaying—features or rasters—determines the methods and tools you'll use and the results you'll get. Overlaying feature datasets The feature overlay functions split features in the input layer where they're overlapped by features in the overlay layer—new areas are created where polygons intersect: lines are split where polygons cross them. These new features are stored in the output layer—the original input layer is not modified. The attributes of features in the overlay layer are assigned to the appropriate new features in the output layer, along with the original attributes from the input layer. Feature overlay tools are located in Arc Toolbox, in the Overlay toolset (in the Analysis toolbox). a 3 -3 _IjT when layers are overlaid—as with Intersect-new layer is created. The features in the new layer have all the attributes of both original layers. 372 373 Using ArcGIS Desktop Conceptually, the various tools are similar—they differ by the feature types they allow you to overlay, by whether you can overlay multiple layers at one time, and by which input and overlay features are maintained in the output layer. Parcels (the input layer) and a Hood zone polygon (the overlay layer). The output of Union contains the features of both the input and overlay layers—features are split where they overlap. Symmetrical Difference is the inverse of intersect—it excludes features common to both input layers. The output of Intersect is only features—or portions of features— common to both the input and overlay layers. Identity maintains the input features—features are split where ovedapped by the overlay features. Update replaces the input features with the overlay features. 5 • Geographic Analysis Intersect and Union can be used to overlay many layers at one time. Use Union to append fields from multiple layers—in this example, slope, soil types, and vegetation types—to find features meeting' specific criteria. New polygons are created where input polygons ovedap. 374 375 Using ArcGIS Desktop Overlaying raster datasets Raster overlay tools are located in several toolsets in the Spatial Analyst toolbox. The Combine tool (in the Local toolset) assigns a value to each cell in the output layer based on unique combinations of values from several input layers. The input values are also added to the output layer's attribute table. 5 • Geographic Analysis * u • -4 d + i 1 DKarca | j f Hytkdoqt j - * , Local ^ Eou* To ftmtfjmrr 'i-r1 tmmm j Ma. | Sm-Ji| Map Algebra—among other things—lets you add layers representing different criteria. Combine assigns values based on unique combinations of values on the input rasters. You can then setect or extract the celts that meet your criteria. Another approach is to mathematically combine the layers and assign a new value to each cell in the output layer. This approach is often used to assign a suitability or risk value to each category in a layer and then add the layers, to produce an overall suitability or risk value for each cell. For example, to find areas suitable for development, you might assign values of 1 (low suitability) to 7 (high suitability) to the various slope values in a raster of slopes. You'd do the same for rasters of soil type and vegetation type. When you add the rasters (using the Map Algebra tool) the cells in the output raster have values ranging from 3 (not suitable) to 21 (highly suitable). The various layers can also be assigned a relative importance (the values in each layer are multiplied by jhat layer's weight value before being summed with the other layers). The Weighted Overlay tool lets you do this. • i m ¥ ■■n ■- a [-TPS. M mm' • 0' 376 377 Using ArcGfS Desktop 5 • Geographic Analysis Spatial Analyst contains many other tools for processing, combining, and summarizing raster data. Some let you combine raster and feature data. For example, the tools in the Zonal toolset let you summarize the values in a raster by categories (or "zones"—all cells having the same category value, whether adjacent or not, constitute a zone) in another raster or feature layer. You'd use the Zonal Statistics tool to calculate the mean elevation for each vegetation type in a J study area. Zonal Statistics (in the Zonal toolset) summarizes cell values for a raster layer (elevation, in this example) for areas representing each category in another layer (vegetation types). You can choose from several statistics. I-EDUM The output is a new raster layer—cells coincident with each vegetation type area are assigned the same mean elevation value (for example, all cells representing conifer forest in the input layer would receive the same mean elevation value in the output layer). A related tool. Zona! Statistics as Table, outputs a table listing a range of summary statistics for the input value raster (shown above). The Tabulate Area tool, also in the Zonal toolset, calculates cross-tabulated areas between two datasets representing zones (or categories). These can be both raster, both feature, or one raster and one feature dataset. You'd use Tabulate Area to calculate the amount of each land cover type in each ownership category. Tabulate Area (in the Zonal toolset) cross-tabulates areas between a layer of zones and classes (land cover types and ownership classes, in this example). The result is a table showing the area of each zone in each class. Measuring distances between features Finding distances is one of the most basic types of geographic analysis. ArcGIS Desktop provides a variety of tools for finding the distance between two locations, finding which feature or features are nearest another feature, and defining the area within a given distance of features. Measuring distance on a map The Measure tool in ArcMap lets you measure the distance between two locations or along a path. Click the start location and double-click at the end location. To measure a path, click as many locations as you want along the way. ihen double-click to end the path. The distance is displayed in the default display units of the map—you can change the units using the drop-down menu on the Measure dialog box. When measuring a path, the length of each segment is displayed along with a running total. Using the Measure tool is a quick way to interactively display distance. The Measure tool also lets you calculate the area of a polygon you draw, or display the coordinates of a point feature. ~B -J. v Snap to Features k * a* a - r Cod Path ^ FutMn HArr^D /• ■ ■ ' > Euldoan tMrXt P PatttDexau ■ * t [HUD j * ..• f CtttlMtrohairr IS A cost surface is required to create a cost distance surface—often cost values are assigned to an existing layer using the Reclassify tool, or multiple layers combined using the Weighted Overlay tool. In this example, relative cost values are assigned to the various types of vegetation, based on the effort to traverse each type. The Cost Weighted option performs the same function as the Cost Distance tool. Another tool. Surface Length, which is provided with the ArcGIS 3D Analyst extension (in the Functional Surface toolset), measures the total length of a line over an elevation surface—taking into account elevation change—rather than over an assumed flat plane. This would be useful, for example, to predict actual miles traveled over mountainous terrain, and resulting fuel costs. Length over surface The Surface Length tool calculates the length of each line—or tine segment—over an elevation surface, ft adds a field (named SLength. by default) containing the new length values. 385 Using ArcGIS Desktop Creating paths and corridors ArcGIS Desktop includes a number of functions that allow you to model the best path or corridor between two or more locations. These functions are based on distance and the resistance involved in traveling between the locations. In general, the goal is to find a solution that minimizes costs. Cost can be measured in terms of distance, money, time, effort, or even social values such as historical importance (a proposed highway that passes through a ruin may be too costly from a societal standpoint). There are two types of paths you can model using GIS: paths over a surface, and network paths. Modeling a path over a surface Modeling a path over a surface is useful when creating new infrastructure, such as a highway, pipeline, or power line. It's also useful for modeling the movement of objects that don't travel over a fixed infrastructure. For example, you could create a managed wildlife corridor between two protected natural areas. The main tool for creating a path over a surface is Cost Path. Cost Path requires, in addition to the location of the destination, two input layers: a cost distance layer and a backlink layer. (A backlink raster layer is an interim layer that several different distance functions use to calculate least cost. It essentially calculates the least cost direction from each cell toward the destination location.) These are in turn created using the Cost Distance tool, which requires the origin location and a cost surface layer (see the previous section. 'Calculating distance over a surface"). The cost distance and backlink layers can also be created using the Path Distance tool, which allows you to specify additional parameters such as wind resistance and the extra distance incurred in traveling uphill and downhill. These tools are located in the Distance toolset, in the Spatial Analyst toolbox (ArcGIS Spatial Analyst must be enabled to use them). The output from Cost Path is a raster dataset. If necessary, you can convert the raster path to a line feature using the Arc Toolbox Raster To Polyline tool, in the From Raster toolset (conversion toolbox). Creating a path using Cost Path is illustrated on the next page. Similar functions are available from the Spatial Analyst toolbar in ArcMap. The Cost Weighted function takes the origin point and a cost surface as input, and creates a cost distance surface and a cost direction surface (comparable to a backlink layer). These then become input to the Shortest Path function, along with the destination point. The output from Shortest Path is a shapefile. rather than a raster. Origin layer 5 • Geographic Analysis The Cost Weighted and Shortest Path functions on the Spatial Analyst toolbar can be used to create a path over a surface- To get started, you need two layers representing the origin and destination locations, and a cost surface raster layer. A path over a surface is created using the Cost Path tool. The result is a raster surface containing the least cost path Cost Path takes as input a layer that contains the destination (end point) of the path, a cost distance surface, and a backlink surface. Here, the path and destination are shown along with the cost distance and backlink layers in the background. Esssl • Use the Cost Distance (or Path Distance) toot to create the cost distance layer (above left) and backlink layer (above hght). The input to this toot is a layer containing the origin of the path (start point) and a cost surface (bottom). A cost surface can be created by reclassifying one or more existing raster surface layers (using the Reclassify tool, in the Reclass toolset). If more than one layer is used, all the layers should be reclassified using the same scale (one to five, for example) The layers can then be weighted and combined using the Weighted Overlay tool or using the Single Output Map Algebra tool. In this example, layers of slope, protected areas, and vegetation have been combined to create a cost surface with values ranging from 3 (low cost) to 13 (high cost). 386 387 Using ArcGIS Desktop 5 • Geographic Analysis The Cost Path tool creates the single least cost path over a surface between two locations. An alternative is the Corridor tool, which assigns each cell the cumulative cost involved in reaching that cell from two locations (or. a cost for reaching either of the locations from that cell). By classifying the cell cost values or selecting cells that have a value less than a certain cost, you can create potential corridors between the locations. This is useful for modeling the movement of wildlife or for creating several potential alternative paths for infrastructure (a highway or pipeline). The corridor tool takes two input cost distance rasters (created using Cost Distance or Path Distance) and creates a cumulative cost raster. Use the Corridor toot in the Spatial Analyst toolbox to create a least-cost corridor between locations- In this example, the lightest areas represent the least cost corridors. The input to Corridor is two cost distance surfaces—one created for each location you want to link. These are created using the Cost Distance or Path Distance tool (described earlier). 388 Modeling a path over a network |n ArcGIS Desktop, a network dataset is used to represent transportation infrastructure such as roads or railroads. Objects can move only along the lines that comprise the network. Examples of modeling paths over a transportation network include finding the best path for a truck from the fire station to a fire or the best route for a delivery truck. Network paths can simply connect two points, or can include stops along the way. See 'Adding specialized datasets to a geodatabasc' in Chapter 2 for more on creating network datasets. The Network Analyst extension allows you to create paths and routes. Open the Network Analyst toolbar in ArcMap click the View menu, point to Toolbars, and click Network Analyst (the extension must be enabled in order to use the toolbar). After adding the network dataset to your map. click the Network Analyst dropdown menu and click New Route. The new route—and all its elements—are added to the table of contents. 0*. o - Create Network Location + 1 - Click to add a stop Click the Create Network Location tool, then add the origin and destination—and any slops along the way—by clicking network edges or junctions. 389 Using ArcGIS Desktop When you've added all the stops, dick the Solve button to create the optimum path between all the stops. Select/Move Locations 5 • Geographic Analysis To modify the route, add more locations or select and move or delete a location, and then click Solve again to calculate the new optimum path. Any costs you built into your network when it was created—such as travel time—or any barriers you add (such as a closed street) will be taken into account when you create the path. Allocating areas to centers Allocation is used to delineate areas of influence, market areas, or service areas around a location or set of locations (referred to as "centers"). Often, the centers represent locations that people travel to (a library) or from (a fire station), essentially, allocation assigns the area nearest each center to that center. As with other distance measures, "nearest" can be defined in terms of straight-line distance or cost (time, money, effort). Creating areas around centers The Create Thiessen Polygons tool in the Proximity toolset (Analysis toolbox) creates a polygon around each input location. The polygon represents the area closest to each location. jam The Create Thiessen Polygons tool creates a layer of polygons around a set of input points—each polygon represents the area closest to the point at its center. OES^.LMHLK Ml ■ . » 3P TO* • & ExbKt - $ rtomty f OJIm / frUbpfe (trig WrW y* WW fl ill |lriti 1 'i * [ The Euclidean Allocation tool in the Distance toolset (Spatial Analyst toolbox) is similar to Thiessen—except it creates a raster (instead of polygons) and assigns each cell to its nearest center. The Euclidean Allocation tool assigns each cell to Us nearest center, using straight-line distance. The celt value is a unique identifier associated with each center (the fire station ID. in this example). ~3 i£ *V* Q V Til -a -a i —i 390 391 Using ArcGIS Desktop 5 • Geographic Analysis The same function is available on the Spatial Analyst toolbar in ArcMap (point to Distance on the drop-down menu, and click Allocation). J12I "3 jtj r The Cost Allocation and Path Distance Allocation tools (in the Spatial Analyst Distance toolset in ArcToolbox) allow you to use costs rather than straight-line distance when assigning cells to their nearest center. The inputs for these tools are similar to the corresponding distance tools (Cost Distance and Path Distance). The Path Distance Allocation tool allows you to use cost factors such as slope and elevation—in addition to straight-tine distance—to assign cells to centers. The result is more representative of the effort required to travel from (or to) the center. -- u a e - |s*s«3|BBaa|i ~3F-~3 ■ ' i A- »- J.- -- 392 Creating service areas using a network If you've built a network dataset. you can use the Network Analyst toolbar in ArcMap to create a service area delineated by traveling along streets (or other network features) to or from the center. ~3 si * • □ w - Create Network Location ~3I"""-. ■ ' ■ A" <*• *l' J. After adding the network dataset to your map, dick the Network Analyst drop-down menu and click New Service Area. The new area—and all its elements—are added to the table of contents. Click the Create Network Location tool, then add the centers or facilities by clicking network edges or junctions. When you've added ail the centers, click the Solve button to create the service area around each center. m" a -» tf. g • *—»»«-* P — —Click to add a center +1 393 Using ArcGIS Desktop 5 • Geographic Analysis You can change the symbols used to delineate the service areas by clicking them in the table of contents. To change the parameters of the allocation, right-click the service area in the table of contents and click Properties. You can, for example, change the maximum distance for the service areas (on the Analysis Settings tab). Modeling flow Use the Layer properties dialog box to change the maximum distance.... ..then click Solve to create the new service areas. V V e~ W *—*r L"* W«— 0» 0 at b # * ' - • * F" a a .if"-} - - » m' a . □ - a B |ä=-3fi~3 a j |> A- »- at- -- Modeling flow lets you see how water or other materials move from a source point (or points) through a network or over a surface. You can see, for example, which portions of an electrical network will be affected if a transformer switches off. or where water falling on a hillside will accumulate. Modeling flow over a network Utility netw orks are represented in ArcGIS Desktop using geometric network datasets (see "Adding specialized datasets to a geodatabase' in Chapter 2). Once you've built a geometric network, you can trace the flow over the network from one or more source points. You can find connected features, find closed loops, trace upstream or downstream, and so on. To do this, you use the Utility Network Analyst toolbar in ArcMap. To open the toolbar, click the View menu, point to Toolbars, and click Utility Network Analyst. Click the Flags drop-down menu on the Utility Network Analyst toolbar to add a source at a junction or along an edge, or to place a barner on the network. Select the flag, then click the location. Once you've placed your sources, select the trace task. 394 395 Using ArcGIS Desktop The results are displayed when you click the Solve button. Click the Analysis drop-down menu to clear the results or flags. and to access the analysis options (for example, to limit the trace to selected features or to change the symbology for the results). 5 • Geographic Analysis Modeling flow over a surface The Hydrology toolset in the Spatial Analyst toolbox contains tools for modeling the flow of water over an elevation surface. You can. for example, define hydrologie basins, identify stream channels, or calculate the distance along a flow path Another set of tools models the flow of water or other material (such as a contaminant) through the subsurface. These tools are included in the Groundwater toolset in the Spatial Analyst extension. The Basin tool (left) calculates hydrologie basins, or watershed areas. The Flow Accumulation tool (right) can be used to identify and create stream networks. The results of the Ihese tools are rasters—you can convert the basins to polygons and the streams to linear features. mutt- «if -^te, vtW-v* tVi, 396 397 Using ArcGIS Desktop Creating raster surfaces Raster surfaces represent phenomena that have values at every point across their extent. They are created from values sampled at a limited set of locations, such as surveyed height values (for an elevation surface), or temperatures collected at weather stations (for a temperature surface). ArcGIS Desktop includes tools for interpolating values between the sampled locations to create a continuous surface. Another type of surface created from sample points shows concentration per unit area (density), such as crimes per square mile. Unlike an interpolated surface, a density surface doesn't predict a value at each location—there may, in fact, not have been any crimes w ithin a particular square mile area during the time period being analyzed. Rather, the density surface provides an indication of the distribution of features or values. Creating an interpolated surface Interpolation tools create a continuous surface from samples with measured values, such as elevation or chemical concentration. There arc several interpolation tools, and each has a variety of parameters that influence the resulting surface. The tools are included in both the Spatial Analyst toolbox (Interpolation toolset) and the 3D Analyst toolbox (Raster Interpolation toolset). 4 A/tToobo. - - % X AnA-a locb ŕ ínc->s /H ŕ 5t*W ^ Topolettasti ŕ Tócoto ftCňt * ^^"^^ • £ = wt tr Surf«» - & HNOMOon • 9 mSurface ,-ŕ1 The same set of surface interpolation tools (including Natural Neighbor) is available in both the Spatial Analyst and 3D Analyst extension products. The Topo to Raster tool is specifically designed to create elevation surfaces. It allows you to input elevation contours, spot heights, and streams to create an accurate digital elevation model (DEM). 398 5 • Geographic Analysis Different interpolation techniques can produce different output surfaces from the same input data, although the broad pattern will be similar. The maps to the left show examples of each tool applied to a set of sample points representing readings at air pollution monitoring stations. The specific parameter choices will influence the results. A particular technique may be suited to particular data or applications. Inverse Distance Weighted (IDW) and Natural Neighbor interpolation estimate surface values for each cell using the value and distance of nearby points. The interpolated values for IDW surfaces are calculated as a weighted average of the values of a set of nearby points. The influence (weight) of nearby points is greater than that of distant points (the weight decreases as the distance increases). Natural Neighbor interpolation is like IDW interpolation, except that the data points used to interpolate the surface values for each cell are identified and weighted using a Delaunay triangulation. as in a TIN. Natural Neighbors interpolation works reliably with much larger datasets than the other interpolation methods. The Spline and Trend tools interpolate best-fit surfaces to the sample points using polynomial and least-squares methods, respectively. Spline interpolation fits a mathematical surface through the points that minimizes sharp bending: it is useful for surfaces that vary smoothly, such as water table heights. Trend surfaces are good for identifying coarse scale patterns in data: the interpolated surface rarely passes through the sample points. Kriging is an advanced surface creation technique that is most useful when there is a spatially correlated distance or directional bias in the data. It is often used in soil science and geology. Several of these tools arc also available from the 3D Analyst and Spatial Analyst toolbars in ArcMap. ~3 ItMnaDbUnc* Wetcftcd, 399 Using ArcGIS Desktop Geostatistical interpolation techniques allow the creation of predicted value surfaces and the interpretation of levels of certainty about the predictions based on confidence levels. The Geostatistical Analyst wizard (included in the Geostatistical Analyst extension) allows surface creation using a number of different methods, including Kriging, Cokriging. Radial Basis Function. Inverse Distance Weighted. Global Polynomial, and Local Polynomial interpolation methods. Geostatistical Analyst lets you analyze how well these various methods will predict values for your particular data. Cre Using Geostatistical Analyst for Inverse Distance weighting ~3 & liHDc-iorx x- r r The wizard lets you specify the interpolation method to use and the mode! parameters, and shows you how well the model you've defined will predict the surface values. The specific parameters—and the corresponding wizard panels— depend on the method you specify. The Geostatistical Analyst toolbar also includes tools for detecting bias or patterns in your data, including histograms, normal QQ plots, and trend analysis. 400 5 ■ Geographic Analysis Creating a density surface Density tools produce a raster surface that represents how much or how many of something there are per unit area. You mjuht use density surfaces to represent the distribution of a wildlife population from a set of observations, or the degree of urbanization of an area based on the number of roads. The Density toolset in the Spatial Analyst toolbox includes tools for creating density surfaces for point and line features, point Density and Line Density search around each cell (within a neighborhood you specify), calculate the density for that neighborhood, and assign the density value to the cell. This is known as a simple density surface. Kernel Density (its a smooth curved surface over each input feature, w ith the surface value diminishing from the feature and reaching zero at the maximum search radius distance. It adds the values of these kernel surfaces to calculate a value for each cell in the resulting density surface. The Kernel Density tool accepts cither points or lines • ■ A simple density surface of population created using the Point Density toot from a layer of census block centroids. d MWW fmkS ... MM «MM . - li -■ Ml InfetHl) 1 im Ann ■ ■• ~^~1 °- I 1 I ■ I A kernel density population surface created using the Kernel Density tool. The Spatial Analyst toolbar in ArcMap also lets you create a density surface—the dialog box accepts either points or lines and will calculate a kernel density or a simple density surface. 401 Using ArcGIS Desktop 5 • Geographic Analysis Creating a TIN surface A TIN. or triangulated irregular network, is a surface data structure composed of triangular facets defined by nodes and edges. They are usually used to represent terrain. The terrain heights are derived from spot elevations that are used as initial nodes in the triangulation. The shape of the TIN surface is controlled by the triangulation of these spot elevations. TINs capture the variation in a surface better than do rasters—the spot elevations can be irregularly distributed to accommodate areas of high variability in the surface and their values and exact positions are retained as nodes in the TIN. This makes TINs well-suited to engineering applications (such as calculating cut and fill). When creating the TIN, you can include other features, such as streams or ridge lines, to refine the TIN surface (these become breaklines that define the edges of triangular facets). Polygons, such as lakes, can be included to create flat planes in the surface. TIN surfaces are created using the 3D Analyst extension. The Create/Modify TIN option on the 3D Analyst toolbar displays a dialog box that lets you specify the input datasets and parameters. The new TIN surface is automatically added to the display. <*—• » - if O- A. * :'- |->«- d ■ ' ■ A.- *- 4- . wxn mm*.**— To create a TIN, point to Create/Modify TIN on the 3D Analyst dropdown menu and click Create TIN From Features. In the dialog box. specify the layer containing the spot elevations, and any other features to use in creating the TIN. 3F~3 . t i You can also create TINs using the Create TIN and Edit TIN tools in the 3D Analyst toolbox (TIN Creation toolset). Create TIN creates an empty TIN dataset—you specify the spatial reference for the dataset. You then use the Edit TIN tool to add points and breaklines to create the contents of the TIN (the faces, edges, and nodes). These tools are useful for creating TfNs inside a script or model. 402 J & Bans' Sufaco & TMCruron fi> rwsurfaa a Use the Create TIN tool to create an empty TIN dataset and specify its spatial reference... ...then use Edit TIN to add points, breaklines. and other features to define the TIN surface. TINs are often best visualized as a 3D surface in ArcScene. Once you've created the TIN (using ArcMap or Arc Toolbox), add the TIN to the scene. Since the 3D Analyst toolbar is available in ArcScene, you can also create TINs within ArcScene. When you add a TIN to a map or a scene, a default rendering is used. In ArcMap. the default is an elevation color ramp. In ArcScene, the faces of the TIN triangles are drawn using a single symbol (although the TIN is drawn in shaded relief). Use the Symbology tab on the Properties dialog box (in either ArcMap or ArcScene) to change the rendering. You can draw the faces using a color ramp for elevation, slope, or aspect; you can also draw the edges of the triangles, the nodes (derived from the original input points), and any breaklines you may have used to create the TIN. «4>M MM m XIJVBt TTCMM I asi» xi mot 29I"32S nCMB QUF73H ,v Ml ■ ■ MODS ."HUH KB 1*JB z 3. _~_l Click Add on the Symbology tab of the Layer Properties dialog box to display the Add Renderer dialog box. Select the renderers you want to add to the list, then click the Add button on the dialog box. Select a renderer from the list to display and modify the symbols. You can create and store a TIN-based surface within a geodatabase by building a terrain dataset (see 'Adding specialized datasets to a geodatabase' in Chapter 2. 403 Using ArcGIS Desktop 5 • Geographic Analysis Deriving data from an elevation surface Surfaces are constructed from x. y. and z (height) values. This allows you to perform geographic analysis>that takes into account height above (or depth below) a fiat plane. Once you've constructed an elevation raster surface or TIN, you can derive new datascts that represent characteristics of the surface, such as slope and aspect. Tools that allow you to derive new surfaces from an elevation surface include Contour, Slope, Aspect, Hillshade, and Curvature. The derived datasets arc useful for input to other analyses, such as overlay analysis, as well as for visualization and cartography. The tools are located in the Surface toolset in the Spatial Analyst toolbox and the Raster Surface toolset in the 3D Analyst toolbox. The Aspect toot calculates the direction of the slope face for each ceil. The aspect of a surface typically affects the amount of sunlight it receives (among other factors). The Slope tool calculates the maximum rate of change from a cell to its neighbors, which is typically used to indicate the steepness of terrain. The Contour tool extracts lines of constant value (isolines) from a raster surface. The TIN Contour tool extracts a line feature class of contours from a TIN surface. Curvature calculates whether a given part of a surface is convex or concave. Convex parts of surfaces, like ridges, are generally exposed and drain to other areas Concave parts of surfaces, like channels, are generally more sheltered and accept drainage from other areas. 404 Hillshade shows the intensity of lighting on a surface given a light source at a particular location; it can model which parts of a surface would be shadowed by other parts. 405 Using ArcGIS Desktop The derived surfaces can be combined with the original elevation surface, or with each other. Displaying contours on top of the elevation surface adds detail to (he map. The hitishade surface is often displayed under the symbolized elevation surface to create a shaded relief map. Set the transparency of the elevation surface using the Display tab on the Layer Properties dialog box. Viewing the surfaces in perspective, using ArcScene. can help you visualize the surface characteristics. 3 »-> +-r«***eQ.: ::'•>•'»•* Displaying the Slope surface in perspective lets you easily see the areas of steepest and flattest slope (see "Creating relief maps and perspective views" in Chapter 4). This perspective view of the Aspect surface shows north-facing slopes (blues) and south-facing slopes (yellows). Contour. Slope. Aspect and Hillshade can also be accessed from the Spatial Analyst toolbar in ArcMap and the 3D Analyst toolbar in ArcMap or ArcScene. JOT &tra. *eB*«rfVBU».. 406 5 • Geographic Analysis When accessing the tools via the toolbars, the default for the output is a "temporary raster," which is automatically added to the map or scene, but not saved. That allows you to preview the analysis parameters and preview the output. To make a temporary raster permanent, right-click the layer name in the table of contents, point to Data, and click Make Permanent. Alternatively, you can create a permanent raster initially by typing a name for the output raster in the dialog box—the raster will be saved in the working directory (set using Options on the Spatial Analyst drop-down menu). Or. type a full pathname to override the working directory setting. The default output for Slope and other surface analysis tools accessed from the toolbar is a temporary raster. Enter a raster name if you want to create a permanent output raster If you accept the default of a temporary output raster, and later want to save it. nghi-ctick the layer name, point to Data, and click Make Permanent. Alternatively, save the map to make all the temporary rasters permanent (they will be given a default name and stored in the working directory). 407 Using ArcGIS Desktop The tools on the 3D Analyst toolbar accept TINs as input, in addition to rasters. The output is still a raster surface for Slope, Aspect, and Hillshade. and line features for Contour. -I The surface analysis tools on the 3D Analyst toolbar accept TINs as input, as well as rasters. a ■□a. n "Tu MM * ■ ran-Mui ;» * I- — — -.' o H = 5 • Geographic Analysis Calculating surface volume ArcGIS Desktop includes a set of tools used to calculate volume from surface information. The tools calculate the difference in volume between a raster or TIN surface and another surface. Depending on the tool, the other surface might be specified by a horizontal plane at a given elevation or by a second raster or TIN surface. Volume calculations are typically used in hydrology and civil engineering applications. The Surface Volume tool is used to calculate volume of a surface above or below a horizontal plane at a specific elevation. You'd use this tool, for example, to calculate the volume of water in a section of river channel at a particular flood stage or to calculate the volume of additional water when a reservoir is near capacity versus its normal level. This tool is available on the 3D Analyst toolbar (as the Area and Volume function) and in the 3D Analyst toolbox (Functional Surface toolset), and can be used on raster or TIN surfaces. The output of the tool is the resulting surface area and volumes, which are displayed on the screen. You can optionally specify to write the results to a text file. The ArcToolbox versions of the TIN tools are located in the TIN Surface toolset, in the 3D Analyst toolbox. ff THSufKf /• rjecrrvste TIN Nodes > TIN tornu* f TViDtttrrce /■ TNSopt The Surface Volume tool calculates the volume between the surface and a flat plane. In this example. Surface Volume calculates the area of the surface of the water and the additional volume of water were the surface to rise three meters above the river bed. 408 The Cut Fill tool (illustrated on the next page) is used to calculate the volume difference—negative or positive—for before and after surfaces of the same area. This tool is used, for example, to calculate the volume of earth that must be dredged from a river channel to improve navigation. Cut/Fill is in the Spatial Analyst toolbox (Surface toolset) and the 3D Analyst toolbox (Raster Surface toolset). It's also available on the Spatial Analyst and 3D Analyst toolbars in ArcMap or ArcScene. The versions of the tools contained in Spatial Analyst accept rasters as input; the versions in 3D Analyst accept TINs (the toolbar version also accepts rasters). In all cases, the results of Cut/Fill are presented as a raster of the difference between the two layers. Cells arc grouped into zones (contiguous cells representing cut areas, fill areas, or no difference areas), and the attribute table for the raster layer stores the volume for each zone. 409 Using ArcGIS Desktop 5 • Geographic Analysis This example shows elevation surfaces of a subdivision before and after grading for a new cul-de-sac. The after surface is subtracted from the before surface, so if the surface has dropped (a cut), material has been removed and the calculated volume is positive. By summing the positive volume you get the total cut volume. Conversely, summing the negative volume gives you the total fill volume. To get the total cut volume, select the records having a positive volume and calculate statistics for those records (see 'Selecting a subset of features'and •Working with a selected set'in this chapter). 21496 7 44397 3 67436 2 33995 6 The TIN Difference tool compares two TINs and identifies each area where the second TIN is above, below, or at the same level as the first TIN. It creates polygon features corresponding to each of these horizontal areas, and codes each polygon as representing an area above, below, or the same. It also calculates volumes above or below these horizontal areas and the second TIN. and assigns them to each polygon. TIN surface showing elevation of a stream valley. The second TIN (shown here on top of the elevation TIN) was created from stream proHles for a fifty-year flood. TIN Difference creates polygons indicating where the second TIN is above (a value of 1). below (a value of-1), or at the same level as the first TIN (a value of 0). By selecting the polygon(s) with a value of 1 (water level above the onginal surface), the fifty-year floodptain area is delineated (shown here in blue on top of the onginal elevation surface). The TIN Polygon Volume tool calculates the volume difference and surface area for each polygon in a layer relative to a TIN surface. Each polygon represents a horizontal area at an elevation specified in a height field. The volume above or below this planar area to the TIN surface is added to the polygon layer's feature attribute table, along with the surface area of the polygon. As with the other surface analysis tools, when the tool is accessed from the toolbar the default output is a temporary layer. Enter a file name to create a permanent layer initially, or—after creating the temporary layer (which is added to the map or scene automatically)—right-click it in the table of contents and click Make Permanent, if you want to save it. 410 411 Using ArcGIS Desktop Analyzing visibility Several tools included with ArcGIS Desktop allow you to calculate which portions of a surface are visible from specific locations. These tools can be used, for example, to site fire lookout towers or find the route for a transmission line that is not visible from a scenic area. Some related tools measure the amount of solar radiation reaching the surface. Measuring line of sight The Line Of Sight tool identifies whether or not one location is visible from another, and whether or not the intervening locations along a line between the two locations are visible. Line Of Sight is available in 3D Analyst, and works with both raster and TIN surfaces. The tool supports offsets, which allows you to specify the height above the ground of the observer and target points. The Line of Sight button on the 3D Analyst toolbar lets you enter the observer and target points interactively. The result is a graphic line that is stored with the map. Click the Line of sight button on the 3D Analyst toolbar, enter optional offsets, then click the observer location and target location on the map. The result is a graphic line showing which portions of the line of sight are visible from the observer location (green) and which are not (red). The target point is likewise color coded as visible or not. The Line Of Sight tool is also included in the 3D Analyst toolbox (in the Functional Surface toolset). The input for the tool is a two-point line. The observer location and target location are defined by the direction the line was digitized—the start point is used as the observer location. The output is a line feature. The advantage of having an output line feature is that you can use the line in further analysis. For example, you could buffer the visible segments to create a view corridor, or overlay the line with land cover to find out which land cover types are visible from the observer point along the line of sight. You also can control the symbology for the line—to make it wider, for example, or change the color scheme. 5 • Geographic Analysis ~2 it a - « □ atOil • » . *|im«— a if *V*n w * * - *f~ Z3 - - i 1 The input to the Une Of Sight toot in the 3D Analyst toolbox is an elevation surface and an existing two-point line feature. The result is a multi-part line—visible sections are assigned a value of 1 (yellow); nonvisible sections have a value of 2 (red). Creating a viewshed The Viewshed tool shows which portions of a surface are visible from one or more observer points. The output is a new raster, with cells coded as either visible or not visible. Viewshed is available on the 3D Analyst and Spatial Analyst toolbars, as well as in both the 3D Analyst toolbox (Raster Surface toolset) and the Spatial Analyst toolbox (Surface toolset). Viewshed combines an elevation surface with a point or line layer containing one or more 'observer" points. The result is a raster layer showing which portions of the elevation surface are visible from the point location(s). ■MBM<.JkU *»* a -" a • l □ • ■ a - _i ~3nr3 » / ■ a - * - ,z - 412 Using ArcGIS Desktop The Observer Points tool (available in both the 3D Analyst and Spatial Analyst toolboxes) is similar to Viewshed. However, it tracks which portions of the surface are visible from each point, or combination of points, and codes the output raster cells accordingly. *-r"—"~r~ Observer Points tracks which portions of the surface are visible from each point, or combination of points. In this example, blue cells are visible from point 1 only, yellow celts are visible from point 2 only, green cells are visible from either point 1 or point 2. and orange cells are visible from point 3. No cells are visible from all three points. Both the Viewshed and Observer Points tools also allow you to specify observer and target offsets, as well as parameters that let you limit the directions and distance each observer can view. 5 • Geographic Analysis Measuring solar radiation \ related set of tools is used for measuring the amount of solar radiation (measured in watt hours per square meter) received at each location across a surface, or at specific locations. The tools. Area Solar Radiation and Points Solar Radiation, are located in the Solar Radiation toolset in the Spatial Analyst toolbox. In addition to the input elevation surface, you specify the time period for which to calculate the solar radiation, and the interval. For Area Solar Radiation, you can create a single, total solar radiation surface, or a separate surface for each interval. Area Solar Radiation creates a raster surface showing the total amount of solar radiation received at each location (that is. for each cell). 3 -1 *»n » In this example, for a one month period for a dataset located in the northern hemisphere, south-facing slopes receive the most solar radiation (orange) while north-facing slopes receive the least (blue). The output for the Points Solar Radiation tool is a dataset of point features, with the solar radiation readings stored as values in the dataset's attribute table. 414 415 Using ArcGIS Desktop Analyzing spatial distributions ArcGIS Desktop includes statistical tools to analyze spatial distributions and trends. These tools allow you to go beyond visual analysis of maps—the calculations use the locations of features and the distance between them, as well as attribute values (in some cases). One set of tools calculates the center and dispersion of a set of features. Other tools calculate the directional trend of features. Calculating the center and dispersion The Mean Center tool calculates the average of the x-coordinates and y-coordinates of all the input features (usually points). The result is a new layer containing a single point (the center). The Standard Distance tool measures the dispersion or concentration of features around the mean center. These tools are located in the Spatial Statistics toolbox, in the toolset titled Measuring Geographic Distributions. The Mean Center toot creates a new point feature representing the location of the average x-coordinate value and average y-CQordinate value of the input features. ■~3 u w «1 % SoaoM look ' & Ar--iVznj Pitt errs - Ql fMpamg ClaJarc. - ^J"; iTOf <<"■- *KCrtUDS * trtra Feature t Oncnor&Oatjt\fa(a**mrZ D*ttHnaj Eat«) t 1>M L.ecttrJ Mean / HrjanCerte £ Sfanoard [>KantB • UUtw ■ u a (Tie Standard Distance tool uses the mean center to calculate the extent to which the distances between the center and the features vary from the average distance. The calculated distance—which represents a standard deviation in map units—is used as the radius of a circle to represent the standard distance graphically on a map. "3B -[1 416 5 • Geographic Analysis You can specify an attribute value in the tool dialog box to calculate the weighted mean center (the center will be pulled toward the features with the highest values). For example, you might calculate the center of business locations weighted hy the number of employees at each business to find a likely location for a transit stop. The weighted central feature and weighted standard distance can also be calculated by specifying an attribute value. ia » «n • - a 5*'* The standard distance is useful for comparing distributions. In this example, the standard distance circle for commercial burglaries (left) is cleady smaller than the one for residential burglaries (right), indicating that commercial burglaries are more concentrated around their mean center Analyzing directional trends The Measuring Geographic Distributions toolset also includes tools for measuring spatial trends. The Standard Deviational Ellipse tool provides a measure of the directional trend of a set of features. The ellipse, which is created as a new feature, is calculated from the mean center. The attribute table for the ellipse includes the x- and y-coordinate of the center, along with the length of each axis, and the angle of rotation. You can specify that the ellipse be calculated using one. two, or three standard deviations. One standard deviation shows the area of concentration of features; three standard deviations shows the area covered by most of the features. The orientation of the ellipse is the same, regardless of the number of standard deviations—only the size is different. As with the standard distance, you can specify an attribute value to calculate the weighted standard deviational ellipse. The standard deviational ellipse shows the orientation of discrete features (usually points). In this example, the standard deviational ellipse for commercial burglaries (using two standard deviations) shows the area where the majority of the burglaries occur. It could be used to decide where to deploy officers. 4 4 AV K IfetfW 9atetrc Took - & Arjivjrfl Pattorrs * O Hana»j r~li in. i - £ -Visjrij Goayaphc [mb-tuto-a «1 -3 % LruMf Pactional Me. t Nea/i Cancer $ Sandard [■stance m\y UtaTOU [■we 'tatxn CLhi : 3 -a :.nr«Mncw»| I »-"-»■■ I 417 Using ArcGIS Desktop 5 • Geographic Analysis The Linear Directional Mean tool calculates the mean direction of a set of line features, based on the direction of each line. Optionally, the tool calculates the mean orientation—the direction the line points is not considered, only its trend (east-west, for example). Mean direction could be used to calculate the downstream trend of a stream network (in this case, the direction the stream segments point is important); mean orientation could be used to calculate the trend of elk migration paths (you don't care which direction the elk move, only the orientation of the paths). When you calculate the directional mean, the circular variance is also calculated. The circular variance is a measure of the extent to which the lines all point the same direction (or in different directions). The closer to 0. the more the lines point the same direction; the closer to 1. the more variability there is in the direction of the lines. The linear directional mean shows the average direction (or orientation, optionally) of a set of line features. The output is a line feature, which you can draw as an arrow. The length of the line is the average length of the input features, and it's placed at the mean center. The attribute table for the directional mean line includes the angle of rotation, the coordinates of the center, and the length of the line. It also includes the circular variance. *~ Anttyang PattCTtt •*MHJV>a &Mgr«ric OWtuDoni • SEG2E2 t ►WCrtr I Sard*dOsura Identifying patterns and clusters ArcGIS includes tools that allow you to identify spatial patterns in your data. Sometimes, apparent patterns you can see when you look at a map will vary depending on how features are symbolized or how values are classified into ranges. The Desktop tools use statistical methods to identify and analyze patterns in the underlying data. They also—in many ca>es -calculate the statistical significance of the results. This "score" tells you how confident you can be that any trend or pattern identified by the tool is not due to chance. All of these tools are located in the Spatial Statistics toolbox in ArcToolbox. The tools in the Analyzing Patterns toolset identify whether ;j set of features (usually points) or values associated with features (usually polygons) form a clustered, dispersed, or random pattern. The Average Nearest Neighbor tool is used to identify patterns in a set of discrete features such as points. J) s Vaataa Foot! - £ AnMyzrt) taxtrrs / awtoaMwMWtf-to- $ nc/Vlt— CLfflwrig 'ma Q t 5p*Oai Aut«or<#auon fMafm I) - b MacOTig Cuttm - & nesting Gaograefr DiAfeubore - & Jrites The Average Nearest Neighbor tool indicates whether discrete features (points, usually) form a clustered or dispersed pattern. If you check the option to Display Output Graphically, a temporary window appears that shows the nature of the pattern (upper bar) and the significance level of any pattern (lower bar). Close the window to finish the tool processing and write the output to the status window. The output values In the example above, the Nearest Neighbor tool has calculated that commercial burglaries in this area are clustered, and there is a less than 1 percent likelihood the pattern is due to pure chance. That is, you can be 99 percent sure the burglaries are, in fact, clustered. 418 419 Using ArcGIS Desktop 5 • Geographic Analysis Moran's I and Getis-Ord General G identify patterns formed by values associated with features—often contiguous features, such as census tracts or counties. They produce a single statistic that summarizes the pattern formed by the spatial disrribution of values. Moran's I looks at whether features with similar values cluster or are interspersed. Getis-Ord General G identifies whether any clustered pattern is due to clustering of high values or low values. $ ndvloi dLstemg ("iots-Crd Inl GJ I »UH)BJnSplMOaf AnnYtti(BtttJy'tKft i ***«JTfl UccociV £»srrt»*>a-rs SI E feus ' DwtteT Ot*W GraaTKifi Is The tools in the Mapping Clusters toolset show where clusters occur. The Anselin Local Moran's 1 tool calculates a statistic and significance value for each feature that indicates how similar that feature's value is to those of neighboring features. It shows areas (clusters) where neighboring features have similar values (either high values or low values) and areas where there is a mix of high and low values. The Getis-Ord Gi* tool also calculates a statistic and significance value for each feature. However. Gi* identifies clusters of high values and low values (hot spots and cold spots). [f ■Hir Moran's / calculates whether similar values cluster or are interspersed, more than you would expect due to random chance. In this example, census tracts having a high percentage of senior citizens occur in clusters, and there is a less than 1 percent likelihood that this is due to random chance. The results are written to the tool's status window and can optionally be displayed graphically. ooi oce oio mmoi oio am aw ' I I AREA ( 1WUH 1 M* n MH-vO.r | ■. ] jt;w coijtjj to p ' tSH ■ XT » - „ 1«' i f eV DDK JIB D.H5JS1 saw Jill «»[7 t*Q.d|«™hlllMB Local Moran's I assigns a statistic—and a significance value—to each feature, based on its similarity to its neighbors. These are added to each feature's record in the output layer's attribute table. You can then map these values to show where features with similar values cluster (orange tracts in this example) or where high and low values are interspersed (blue tracts). 420 421 Additional Resources for Learning and Using ArcGIS Desktop Here are some additional sources of help and information available to you as you learn and use ArcGIS Desktop. Data ArcGIS comes with a number of geographic data sets you can use to start making maps quickly. These are found on the ESR1 Data & Maps Media Kit. The data sets consist of global or national base map data, and include: World Continents Topography and bathymetry Countries Shaded relief Cities 150 meter resolution satellite imagery Lakes/Rivers Latitude and longitude grids Ecoregions Demographics Europe Countries Provinces Cities/Urbanized areas Roads/Railroads Waterbodies Demographics Canada Provinces Cities/Municipalities Indian reserves Highways/Railways National/Provincial parks Waterbodies Mexico States Cities/Municipalities Roads/Railroads Elevation contours Water bodies'Rivers and streams United States States Counties Cities/Populated places ZIP Codes Census tracts/Census block groups County population data Congressional districts Cultural features Highways/Roads Detailed streets (StreetMap USA) Water bodies/Rivers and streams State Plane Zones USGS Topographic Quad Series Indexes See the data Media Kits for a complete list of datasets. 423 Using ArcGIS Desktop Appendix Tutorials Quick-start tutorials are available for the various applications and functions within ArcGIS. They can be accessed from within the ArcGIS Desktop Help system—look under 'Getting more help' in the 'Getting Started' section of the Help contents (or search using the keyword "Tutorials"). The tutorials are in PDF format and require Adobe Acrobat to view them. The sample data to use in conjunction with the tutorials is installed optionally from the ArcGIS Desktop software installation media. The default location for the tutorial data is the arcgisVArcTutor folder. ArcGIS application overview tutorials • Using ArcCatalog—organizing, previewing, and managing geographic datasets • Using ArcMap—making maps, and querying and analyzing geographic data • Using ArcReader—viewing and querying maps published with ArcGIS Publisher Data management and processing tutorials • Building geodatabases—designing and building a geodatabase for storing and managing geographic data • Editing geodatabases—creating and editing specialized geodatabase feature classes • Editing GIS features—creating and editing feature geometry and attributes, and performing spatial adjustment • Geocoding in ArcGIS—assigning geographic coordinates to locations or events from a list of street addresses • Geoprocessing in ArcGIS—working with tools for managing and analyzing geographic data • Linear Referencing—defining, managing, and analyzing routes over GIS networks • Representations—creating cartographic representations for rules-based symbology Extension product tutorials Tutorials are also available for most of the ArcGIS extension products. Dafa compilation extensions • ArcScan for ArcGIS—importing scanned data • ArcGIS Data Interoperability—convening geographic data between various formats • Using Survey Analyst—managing land survey data • StreetMap—working with street and address data • Schematics—creating schematic views of GIS networks and tabular data Mapping and visualization extensions • Maplex for ArcGIS—placing label text for cartographic production • Using Publisher—creating and publishing map documents for use with ArcReader • Using 3D Analyst—creating 3D perspectives and globe views • Using Tracking Analyst—working with mobile features, and creating time-based displays and animations Geographic analysis extensions • Using Spatial Analyst—analyzing and modeling geographic data • Geostatistical Analyst—modeling surfaces from sample points Books Courses from ESRI 424 Conferences and user groups ESRI Press publishes a variety of GIS-related books, including ESRI software workbooks, such as Gelling to Know ArcGIS Desktop, and industry-specific case studies and applications. Several ESRI Press books cover the concepts and methods behind many of the geodatabase design, map design, and geographic analysis tasks presented in this book: • Modeling Our World: The ESRI Guide to Geodatabase Design describes the various models for representing geographic data and the various components of a geodatabase. • Designing Geodatabases: Case Studies in GIS Data Modeling describes the geodatabase design process in detail and provides examples from a variety of industries. • Designing Belter Maps: A Guide for GIS Users covers the basics of map design and production, including layout, fonts and text, symbols, and color selection. • The ESRI Guide to GIS Analysis. Volume I: Spatial Patterns & Relationships describes the use of maps for visual analysis, including types of maps, classification schemes, and use of perspective views. It also covers basic GIS analysis tasks, including feature selection, overlay analysis, and distance analysis. • The ESRI Guide lo GIS Analysis. Volume 2: Spatial Measurements & Statistics describes concepts, methods, and tools for statistical analysis of geographic distributions, patterns, clusters, and directional trends. ESRI Press is online at hllp://gis.esri.com/esripress. ESRI provides both instructor-led and online courses. These cover a wide range of topics and levels, from introductory courses on ArcGIS, to advanced database management and programming classes. Online offerings—at the Virtual Campus—also include courses on industry-specific applications. Go to Training at www.esri.com. Finally, other ArcGIS users are a great source of information and help. ESRI user groups exist in many places around the world, and many of them hold local, regional, or national conferences and meetings. ESRI also sponsors an annual International User Conference, as well as other regional user conferences. These conferences provide a great opportunity to learn from other users' experiences. For more information see Events at www.esri.com. 425 Index Symbols 3D Analyst. See ArcGIS 3D Analyst A Add Field 206, 352. See also Fields Add Join 357 Add Link 242 Address locator 63, 79, 80, 142, 165-66. 168 Add Route Events 169, 171 Adjust 240-45 Aerial photo 132. 154, 162. 190 Align map elements 315 model elements 43 Allocation 345,391-94 Animation 264,271-72 Animation toolbar 329-35 ArcGIS Tracking Analyst 51,336-37 Annotation 20, 28,268, 304 geodatabase 83, 108,208-17,218,250 map document 207-08 Anselin Local Moran's I 421 Append 247 ArcCatalog 2, 7, 8, 15.46. 52, 53. 55. 57 andArcMap 265,266,273,274 and ArcToobox 35, 36, 38,43 building geodatabases 102^45, 147, 148.209-10, 217, 218. 221, 222, 226, 236,291 data compilation 157, 159. 160, 162, 166, 168 described 29-34 distributed geodatabases 260, 262 geographic data management 67. 72, 75, 76, 85, 87-101 multiuser geodatabases 249,251. 254. 256. 258 ArcEditor 47. 52 ArcGIS 3D Analyst 50, 264 animations 328 displaying TINs 135,403 perspective views 325-26 surface analysis 344^»5. 385, 409, 412-13,414 surface creation 398, 399,402-04. 406. 408 ArcGIS Data Interoperability 47. 163 ArcGIS Desktop extensions 46, 47-51 ArcGIS Geostatistical Analyst 35, 50, 344. 345, 400 ArcGIS Network Analyst 51, 138-39, 340, 344, 345. 389 ArcGIS Publisher 49, 56 ArcGIS Schematics 48 ArcGIS Spatial Analyst 35,49, 340, 344. 345 allocation 392 distance analysis 383-85 modeling flow 397 path analysis 386-88 raster overlay 376-78 shaded relief 325 surface analysis 409 surface creation 398-99.401. 404, 406.407 visibility analysis 413,414, 415 ArcGIS Tracking Analyst 51, 272, 333. 336-37 ArcGlobe 264, 272, 279 animations 328-32, 333 Arclnfo 47, 48. 52. 303 ArcMap 2-13. 14. 46, 49, 52, 53, 55, 56. 57. 72 and ArcCatalog 29, 31, 34 and ArcToolbox 35, 36,37, 38, 39,43 animations 328-32, 333-35 data selection 360-68 data validation 230, 233-34. 236 described 15-28 digitizing 190, 194-95 editing in 172-89,201 -29, 254-59, 261 geographic analysis 345, 346 mapping 264—327 quick tour 2-14 selection 360-68 spatial adjustment 240 tabular data 348-59 ArcReader 49. 56 ArcScan for ArcGIS 47. 154, 196-200 ArcScene 75. 135. 264. 271, 272, 279, 326, 328-30. 332, 333,403, 406, 409 ArcSDE geodatabase. See Geodatabases 427 Using ArcGIS Desktop Index ArcToolbox 2. 14, 15,29,31,46,52,53,55,59,72,92. 142. 152, 340. 345, 346 data compilation 161-63, 168. 171, 225, 237, 247 data extraction 369-72 described 35-45 distance analysis 380-88, 391-92, 397 distributed geodatabases 262 multiuser geodatabases 259 overlay analysis 373-78 quick tour 10—13 selection 363 shaded relief 325 spatial statistics 416-21 surface analysis 409-11.413-15 surface creation 398-99,401.403-06. 408 tabular data 351,354,357 ArcView 52.96 ArcView GIS 76 Area 409 Area Solar Radiation 415 Aspect 404-06.408 Attribute index 146-47, 148 Attributes defined 64 displaying 31, 51,68, 73-74, 87-88. 129. 273, 283-85,348-51 documenting 51,97, 157 editing 28,34, 180, 201-06 graphs 318-19 in geodatabases 78. 83, 105-06, 107, 124 labels 300-01.307 reports 321-23 selecting by 11-12,286-87.363 summarizing 28. 348^t9. 365 symbolizing features using 268, 288. 289, 293-95. 327 transferring between features 240,246-47 Attributes dialog box 201 -03, 205-06, 216, 221, 230-32 Attribute table defined 18 editing attributes in 204-06 selecting features in 287 viewing 9-10, 26, 31, 87-88. 129 See also Fields; Tables Attribute Transfer 246-47 Average Nearest Neighbor 419 428 B Basin 397 Bookmarks 279 Buffer 342,345, 380-82 Build Pyramids 147 C CAD 56.75. 110. 152-53, 162,240 Cartographic representation 290-91 Center. See Mean Center; Central feature Central feature 417 Charts 295 Classification numeric values 292-93 Clip 369 Clusters 343,345,420-21 Cokriging 400 Color custom 305 specifying 288-89. 305 Combine 376 Command line 38-39,40,41,55 Configuration keywords 107, 109, 211, 218 C ounce; databases in ArcCatalog 29-30, 85 geometric network editing 228 model elements 43 Connections ArcCatalog 29,85-86, 103,256,265,273-74 Connectivity 79, 139, 141, 226, 229, 230. 232-33 Connect to Folder 85 Contents tab 30, 87 Contour 404, 405, 406, 408 Contour lines 81. 134.405.406,408 Control points coordinate system 72 digitizing 190-93, 194 spatial adjustment 240 Converting coordinate systems 239 data formats 66, 152, 153, 157, 160. 161, 162 features to graphic objects 308 labels to annotation 209. 304 symbols to cartographic representations 291 Coordinates. See Geographic coordinates Coordinate systems assigning 34,82. 107-09. 158.237-39 data frames 276 defined 69-72 feature datasets 78,113-14 viewing 94 Copying annotation 208,211 ArcCatalog entries 30,32,93-94. 160 attributes 246-47 data frames 310-11 features 179-80, 226 layers 269.277-78 symbols 298 Corridor 386, 388 Cost Allocation 392 Cost Distance 383-84, 385, 386-87, 388 Cost distance surface 384, 388 Cost Path 386-88 Cost surface 384, 387 Cost Weighted 386 Coverages 33, 56, 75, 76, 77, 78, 95, 152, 157, 160 Create/Modify TIN 402 Create Layer From Selected Features 366 Create Network Location 389, 393 Create Routes 142, 143, 225 Create Thiessen Polygons 391 Create Thumbnail 89 Create TIN 402.403 Create TIN From Features 402 Crystal Reports 321,324 Curvature 404, 405 Cut/Fill 409-10 D Data extraction 340, 345, 346, 369-72 Data frames 22. 172, 265. 270.282, 301, 302 active 24,269, 311-14 adding data to 267. 278. 280 defined 16 layout view 23-25, 307, 309-12, 313, 316 Data Interoperability extension. 5«» ArcGIS Data Interoperability extension Datasets defined 17,66 Data view 5. 15.23, 27, 307. 309 Datum 72 DBMS 56, 80, 103, 107, 111, 248, 250 Define Projection 237 Deleting annotation 207, 211 ArcCatalog entries 30. 32, 93, 128 data frames 269 domains 121 features 28, 177. 179-80,226 fields 111, 112 geodatabase versions 259 links 242, 245 subtypes 122 symbols 298 topology 117 DEM 49. 162,325.398 Density 345,398,401 Desktop Help 1. 14 described 57-61 Digitizing 76,82, 154, 158 by scanning 196-200 on-screen 190-93 using a digitizing table 194-95 Dimensions 218-21 Directional trend 343, 345, 416,417-18 Disconnect databases 29-30,86 geometric network features 227 Display tab Layer Properties 27. 267. 285. 325 Report Properties 323 table of contents 22 Distance analysis 342, 344, 345. 379-94 Distance surface 383 See also Euclidean Distance; Cost Distance DLG 75, 152, 163 Domains attribute 79, 82, 104, 119-21, 123. 201, 203, 230-32 spatial 114.237 Draw toolbar 305-07 with annotation 207-08 w ith map elements 313. 3 15 Edge match 240. 244-45 Edges 173, 181 network 136, 137. 139, 141,228 TIN 402.403 429 Using ArcGIS Desktop Index Editing annotation 207-17 attributes 201-06 dimensions 218-21 distributed. See Geodatabases features 176-89 multiuser. See Geodatabases routes and networks 222-29 symbols 298-99 Edit session managing 173-75 starting 172-73 Edit Table 353 Edit TIN 402-03 Edit tool 179.211,245 Elevation surface 325, 404-6 Environment Settings 40 Erase 369 ERDAS 162 ESR1 Developer Network 61 ESRI Press 81,425 ESR1 Support Center 60, 61 Euclidean Allocation 391 Euclidean Distance 383. 385 Events 64, 333 in linear referencing 79, 145, 165, 169-71,222,225 Export 33, 162, 163, 170. 171. 278, 322, 367 Exporting animations 332, 335 datasets 33.47, 160-61. 162-63 geodatabase schema 103 graphs 319-20 layers 18, 170, 171,278 maps 27 metadata 101 models 45 reports 322 selected sets 28, 367 Extend 183-84 Extension products. See ArcGIS Desktop extensions Extract. See Data extraction Extract by Attributes 371 Extract Data 106 Extract Values to Points 372 Feature classes creating in a geodatabase 107-08, 110-12 denned 65. 66 Feature datasets creating 78. 113-15 defined 75 Field Calculator 204-05, 352,368 Fields adding to a table 34, 53, 110-12,206, 352, 354 calculating values for 201, 204-05. 352-53, 368 default values for 119 defining 107. 109 deleting III. 112,352 formatting 349 hiding 205, 349, 350 primary display field 203 summarizing values in 31. 88. 348-49, 351 viewing 94, 205 Fields tab ArcCatalog 112. 119, 120, 133 ArcMap layers 203, 205. 284,285, 349 Report Properties 321 File geodatabase. See Geodatabases Find 27, 88. 286 Find Now 91,92 Flow 342, 344, 395-97 Flow Accumulation 397 Flow Direction 397 Frequency 340, 345, 349, 351 Geocoding 142, 165-68 Geodatabases ArcSDE 80.85. 102, 103, 109. 110, 111, 146. 149, 211,218, 248.249,254, 260 compacting 148. 149 compressing 148^19,252 copying 160 creating 81-84, 102-06 creating datasets in 107-45 data models 61, 81, 82, 84, 103 defined 76, 77-80 distributed 248,260-62 file 80, 102, 110, 148-49,211,218 importing data into 161-63 multiuser 248, 249-59 personal 80. 102, 110, 146, 148, 149 Geodatabases (continued) replicas 248,260-62 versions 80,248, 249, 254-59 viewing contents of 87 Geographic coordinates 69-72, 153. See also Tolerance Geography Network 85, 86, 98,266, 275 Geometric networks 340. 395 creating 139^11 defined" 79, 139 editing 226-29 modeling flow over 395-96 multiuser editing 249, 250, 251 validation 233 Geoprocessing 35-36,40,61.67. 159. 162,346 Georeferencing 69, 108. 190 Georeferencing toolbar 191, 193 Geostatistical Analyst. See ArcGIS Geostatistical Analyst Getis-Ord General G 420 Getis-OrdGi* 421 CIS servers 29, 85, 95, 265 Global Polynomial 400 Globe view 271,272,328-29 GPS 153, 164,276 Ciraphic objects 15, 21,23, 26-27, 268, 305-08. 313 Graphic text 20-21,268,301,305.307 Graphs 318-20 Group layer 22, 163. 278 H Help. See Desktop Help Hillshade 325,331,404-06,408 I Identify 27, 87, 129, 283-85, 286 Identity 374 Images 65.75.77, 162.289 digitizing from 154,190 importing 132-33, 161 symbolizing 289 Importiii!; 33. I 57 CAD data 162-63 coordinate systems 108.113,237-39 fields 111 geodatabase schema 103-04 metadata 101 Importing (continued) rasters 131-32 symbol definitions 291,297 Index. See Attribute index; Spatial index Internet 29,56, 159, 160,264.270 adding data from 265. 266, 275 finding data on 85,156 Interpolation 344. 345. 398^100 Intersect 373, 374, 375 Inverse Distance Weighted (IDW) 399.400 Join 355-57 Junctions 136. 138, 139, 141.222.226,228 Kemel Density 401 Keyword. See Configuration keywords Kriging 345. 399, 400 Labels 15.268,300-02 converting to annotation 207-09. 304 defined 20-21 See also Maplex for ArcGIS Layer defined 17-18 properties 27 Layer file 278,296-97 defined 18 Layout toolbar 310, 316 Layout view 2, 3,5. 23-25,27, 269, 309-10, 313 Legends 309,311.313 LiDAR 79. 108. 134 Linear Directional Mean 418 Linear referencing 79, 142-45, 165, 169-71.225 Line Density 401 Line of Sight 412-13 Links georeferencing 190-93 spatial adjustment 240.241-45 Link Table 192,242 Load Data 105, 131, 133. See also Importing Local Moran's I. See Anselin Local Moran's 1 Local Polynomial 400 430 431 Using ArcGIS Desktop Index M Magnifier/Viewer window 173-74. 192,282 Make Route Event Layer 171 Map Algebra 377. 387 Map document defined 15 opening 265 saving edits in 173 Map elements 3, 5, 23-24, 270,309, 312. 313-17 Map extent 16, 173, 267, 279-80, 282 Map layout 3. 16.23,269-70, 309-12,316,317 Maplex for ArcGIS 48, 302-03 Map projection 71,237-39 Map scale 279, 280-82 Map templates 312 Map Tips 285 Mean 349 Mean Center 416-17 Measure 379 Merge 247 Metadata 98, 99, 100, 101 editing 99-100 formatting 99 printing 97-98 viewing 8, 31. 72, 88 Mileposts 64. 108, 142, 143, 145, 165, 169, 170. See also Linear referencing ModelBuilder 42-45 Models data 64-65 geoprocessing 40. 42^t5, 346 georelational 74 See also Geodatabases Moran's I 420 MrSID 162 Multiple Ring Buffer 381-82 MyPlaces 279 N Natural Neighbor 398. 399 Near 380 Neatlines 270.314 Network spatial 48, 51. See also Geometric networks: Network datasets Network Analyst. See ArcGIS Network Analyst Network datasets 79 analysis with 389-90, 393-94 creating 136-39 New Displacement Link New Group Layer New Route 389 New Service Area 393 Nodes TIN 402,403 topology 186, 187,234 Normalization 293 North arrows 3,313-14 Observer Points 414 Open Attribute Table 9, 204, 348 Orthophotos 77, 152. 190 Overlay analysis 341, 344, 345,346, 373-78 Overview Window 282 Pan 25, 27. 204, 267, 279, 282,286, 310, 316 Pasting 2 inArcCatalog 94, 160 features 179-80 layers 278 Path Distance 385, 386-87, 388 Path Distance Allocation 392 Paths 342, 345, 386-90 Patterns 343,345,419-20 Personal geodatabase. See Geodatabases Perspective views 50, 271, 326-27, 328,406 Point Density 401 Point Distance 380 Points Solar Radiation 415 Preview tab 31, 87-88 adding a field 112,354 raster catalog 133 summary statistics 351 topology errors 236 Printing maps 4, 368 metadata 99 graphs 319,320 reports 322 Project 239 Projection. See Map projection Pyramids raster 147 terrain 134 Query Builder 12, 144,371 Quick Export 163 Quick Import 163 Radial Basis Function 400 Rasters analysis 345 building pyramids for 147 described 65-66,71,74 extracting a subset 370-71 overlaying 376-78 projecting 239 sampling 372 storing in a geodatabase 78, 130-33 symbolizing 289 viewing properties 95 Raster catalog 132-33, 147 Reference scale 209-10, 218, 302, 304 Relate 357-58 Relationship class accessing in ArcMap 129 creating 124-28 described 79 editing attributes 205-06 managing 128 validating 232 Remove Join 355 Replicas. See Geodatabases Reports 321-24 Representations. See Cartographic representations RMS error 194,242 Rotate annotation 207, 211 feature 179, 180 Routes 138-39 creating 142-45 editing 222-25 linear referencing 169-71 Rubber sheet 240, 244 Sample 372 Satellite image. See Images Save As Layer File 296,366 Scale. See Map scale: Reference scale Scalebars 314 Scanning 82, 154, 190-93, 196. See also ArcScan for ArcGIS Scripts 40-42,45,61, 161, 171,225,300.346 Search ArcCatalog 90-92 ArcToolbox 37 Desktop Help 57 Geography Network 275 Select 363 Select By Attributes 12, 363 Select By Location 362, 382 Selected set adding to/removing from 364 and layer files 18 calculating values 204, 368 clearing 287,365 defined 17 exporting 278,367 related tables 129 saving 366 summarizing 365, 368 viewing 22,204,360 zoom to 13-14 Select Features 360,364 Selection by attribute 12,363 by location 362 edit session 201-02.204 in attribute tables 287 interactive 360 related tables 129,358 setting selectable layers 22, 361 Selection tab 22,361,366 Select Layer By Attribute 11. 12, 363 Select Layer By Location 362, 382 Service areas 138.391-94 Shaded relief 49, 272, 325, 328, 331 Shapefiles 56. 76, 77, 78, 152, 160 importing to a geodatabase 161 Shortest Path 386 Sketch tool 176, 177, 178,214 432 433 Using ArcGIS Desktop Index Slope 404-08 Snapping digitizing 195 editing dimensions 219 editing features 172-73. 175, 181-82, 185 geometric networks 141,229 spatial adjustment 240,241,246 topology 115-17 vectorization 197 Solar radiation 415 Sort 345, 348, 351 Source tab 22. 166, 173.257,278 Spatial adjustment 240-47 Spatial Analyst. See? ArcGIS Spatial Analyst Spatial index 146 Spatial join 355,359 Spatial reference 34, 88, 97, 114, 140, 158, 237,276. See also Coordinate systems Spatial statistics 416-21 Spheroid 72 Spline 399 Split datasets 345,370 features 182 SQL (structured query language) 12, 73. 301, 363 Standard deviation 343. 348 Standard Deviational Ellipse 417 Standard Distance 416-17 State Plane 71,237 Statistics 10,88.343,345,349,351 Style address 142 dimension 218, 221 metadata 31. 97. 100 symbol 20, 288. 298-99 Subset 340, 352, 360, 367 Subtype 79, 119, 121-23, 128.201,203,230-32 Suitability analysis 346, 373, 376 Summarize 348,351,368 Summary statistics 345,351. 365 Surface analysis 345,404-15 creation 345,398-403 See also Elevation surface: Rasters Surface Length 385 Surface Volume 409 Symbology tab 6. 268. 288-89. 291. 292-94. 295. 297, 337, 403 Symbols annotation 210-11,216-17 assigning to layers 6. 9. 54. 268, 288-89, 292-95 cartographic representations 290-91 custom 298-99 defined 18-20 graphic objects 305 importing 297 labels 300-01 map elements 314 saving 296 subtypes 123 Symbol Selector 6,9, 54, 216, 217, 288, 293 Symmetrical Difference 374 Tables 73-74,78 appearance of 350 creating 109 editing attributes in 204-05. 206 exporting records 367 joining 355-59 related 79,124-29,205-06,355-59 selecting features in 12,287 standalone 78, 109, 124, 348, 355 viewing 31, 88, 348 See also Attributes; Attribute table; Fields Table Select 363 TabletPC 164 Tabular analysis 340, 344. 345 Tabulate Area 378 Temporal data 51,333,336 Terrains 79.134-35.340,403 Text. See Graphic text Thiessen polygons 391 Thumbnails 33,87,89 Time series 333, 337 TIN (triangulated irregular network) 344. 345. 402-03, 404,405,408.409,411.412 TIN Contour 405 TIN Difference 411 TIN Polygon Volume 411 Titles 270,313 Tolerance cluster 115-16, 117, 118 selection 2N5 snapping 175 stream 195 XY 107, 113,211 Topology defined 78 editing 186-89 geodatabase 115-18, 186, 187 map 186 validating 233-36 Topo to Raster 398 Trace 344, 345, 395-96 Trace tool 198 Tracking Analyst. See ArcGIS Tracking Analyst Transform 241-43. See also Georeferencing Transparency 27, 325, 330 Trend 399 Turns 136-37 U Undo 173,205,243,353 Union 35,374, 375 Update 374 Utility Network Analyst toolbar 139, 344. 395 UTM (Universal Transverse Mercator) 71, 237 Validate Features 230-33 Validation attribute values 230-32 geometric networks 233 relationship classes 232 topology 115. 117, 118.233-36 Vector data 65, 108, 163, 190,344 Vectorization 196 Versions. See Geodatabases Versioned datasets 249,251-53, 258,259,260 Versioning 80, 248. See also Geodatabases; Versioned datasets Vertex digitizing 195, 198 editing 177-78. 186-87 snapping 115. 173.241 View shed 413,414 Visibility analysis 342,412-14 Volume 409-10.411 W Weighted Overlay 376-77, 384, 387 Workspaces creating 93 defined "5 organizing data in 76-77,93-94. 160 Zonal Statistics 378 Zoom 13-14.267.279,286,316 ArcGIS 9 Using ArcGIS Desktop ISBN-13: 978-1-58948-167-1 S59.95 ISBN-10: 1-5B948-167-4 ESRI ESRI • 380 New York Street • Redlands, CA 92373-8100 909-793-2853 • FAX 909-793-5953 • www.esri.com 9ll781 589ll48167lH 5 5 9 9 5 104124 RRD15M10/07hc Printed in the USA 978158948167155995