SAGA-GIS Module Library Documentation (v2.1.3)

Module Terrain Map View

This module allows to create different terrain visualisations from an elevation dataset:

* Topography: a simple map with an analytical hillshading of the terrain

* Morphology: a map which visualizes the terrain by combining positive and negative openess (Yokoyama et al. 2002) with terrain slope in a single map. In contrast to conventional shading methods this has the advantage of being independent from the direction of the light source.

References:
Yokoyama, R. / Shirasawa, M. / Pike, R.J. (2002): Visualizing topography by openness: A new application of image processing to digital elevation models. Photogrammetric Engineering and Remote Sensing, Vol.68, pp.251-266. online at ASPRS.

Parameters

 NameTypeIdentifierDescriptionConstraints
InputDEMGrid (input)DEMDigital elevation model.-
OutputShade (*)Grid (optional output)SHADEThe shaded DTM.-
Openness (*)Grid (optional output)OPENNESSThe difference of positive and negative openness.-
Slope (*)Grid (optional output)SLOPEThe calculated terrain slope [radians].-
Contours (*)Shapes (optional output)CONTOURSThe generated contour lines.-
OptionsMethodChoiceMETHODChoose the map type to generate.Available Choices:
[0] Topography
[1] Morphology
Default: 0
Radial LimitFloating pointRADIUSRadial search limit for openness calculation.Minimum: 0.000000
Default: 1000.000000
Contour LinesBooleanCONTOUR_LINESDerive contour lines.Default: 1
EquidistanceFloating pointEQUIDISTANCEContour lines equidistance [map units].Minimum: 0.000000
Default: 50.000000
(*) optional

Command-line

Usage: saga_cmd grid_visualisation 8 -DEM <str> [-SHADE <str>] [-OPENNESS <str>] [-SLOPE <str>] [-CONTOURS <str>] [-METHOD <str>] [-RADIUS <str>] [-CONTOUR_LINES <str>] [-EQUIDISTANCE <str>]
  -DEM:<str>          	DEM
	Grid (input)
  -SHADE:<str>        	Shade
	Grid (optional output)
  -OPENNESS:<str>     	Openness
	Grid (optional output)
  -SLOPE:<str>        	Slope
	Grid (optional output)
  -CONTOURS:<str>     	Contours
	Shapes (optional output)
  -METHOD:<str>       	Method
	Choice
	Available Choices:
	[0] Topography
	[1] Morphology
	Default: 0
  -RADIUS:<str>       	Radial Limit
	Floating point
	Minimum: 0.000000
	Default: 1000.000000
  -CONTOUR_LINES:<str>	Contour Lines
	Boolean
	Default: 1
  -EQUIDISTANCE:<str> 	Equidistance
	Floating point
	Minimum: 0.000000
	Default: 50.000000