—  Charakter	
  
—  Slope	
  
—  Aspect	
  
—  Curvature	
  
—  Hilshade	
  
—  Vymezení	
  
—  Contour	
  
—  Srovnání	
  
—  Cutfill	
  
—  Viditelnost	
  
—  Visibility	
  
—  Viewshed	
  
—  Observedpoints	
  
—  Maximální	
  z	
  změna	
  
A B C D
E F G H
I J K L
M N O P
• Using	
  the	
  elevations	
  of	
  the	
  surrounding	
  eight	
  
points	
  in	
  a	
  3	
  x	
  3	
  neighborhood.	
  
• To	
  calculate	
  the	
  slope	
  and	
  aspect	
  for	
  cell	
  “F”	
  
needs	
  elevations	
  at	
  point	
  A,	
  B,	
  C,	
  G,	
  K,	
  J,	
  I,	
  E	
  
A B C D
E F G H
I J K L
M N O P
1.  Calculate east-west gradient:
∆X = ((ZC + 2*ZG +ZK) – ZA+2*ZE+ZI))/8*cell size
2.  Calculate north-south gradient:
∆Y = ((ZA + 2*ZB +ZC) – ZI+2*ZJ+ZK))/8*cell size
tan(Slope(F))	
  =	
  squrt((∆x)2+	
  (∆Y)2)	
  
	
  
tan(Aspect(F))	
  =	
  ∆x	
  /	
  ∆Y	
  
	
  
A(80) B(74) C(63) D(89)
E(69) F(67) G(56) H(78)
I(60) J(52) K(48) L(60)
M(59) N(49) O(47) P(40)
Aspects	
  indicate	
  the	
  steepest	
  downslope	
  direction	
  
Aspects	
  are	
  measured	
  clockwise