SAGA-GIS Module Library Documentation (v2.2.2)

Module Valley and Ridge Detection (Top Hat Approach)

Calculating fuzzy valley and ridge class memberships using the Top Hat approach. Based on the AML script 'tophat' by Jochen Schmidt, Landcare Research.

References:
Rodriguez, F., Maire, E., Courjault-Rad'e, P., Darrozes, J. (2002): The Black Top Hat function applied to a DEM: a tool to estimate recent incision in a mountainous watershed. (Estib`ere Watershed, Central Pyrenees). Geophysical Research Letters, 29(6), 9-1 - 9-4.

Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationGrid (input)DEM--
OutputValley Depth (*)Grid (optional output)VALLEY--
Hill Height (*)Grid (optional output)HILL--
Valley IndexGrid (output)VALLEY_IDX--
Hill IndexGrid (output)HILL_IDX--
Hillslope Index (*)Grid (optional output)SLOPE_IDX--
OptionsValley RadiusFloating pointRADIUS_VALLEYradius given in map units used to fill valleysMinimum: 0.000000
Default: 1000.000000
Hill RadiusFloating pointRADIUS_HILLradius given in map units used to cut hillsMinimum: 0.000000
Default: 1000.000000
Elevation ThresholdFloating pointTHRESHOLDelevation threshold used to identify hills/valleysMinimum: 0.000000
Default: 100.000000
Slope IndexChoiceMETHOD-Available Choices:
[0] default
[1] alternative
Default: 0
(*) optional

Command-line

Usage: saga_cmd ta_morphometry 24 [-DEM <str>] [-VALLEY <str>] [-HILL <str>] [-VALLEY_IDX <str>] [-HILL_IDX <str>] [-SLOPE_IDX <str>] [-RADIUS_VALLEY <str>] [-RADIUS_HILL <str>] [-THRESHOLD <str>] [-METHOD <str>]
  -DEM:<str>          	Elevation
	Grid (input)
  -VALLEY:<str>       	Valley Depth
	Grid (optional output)
  -HILL:<str>         	Hill Height
	Grid (optional output)
  -VALLEY_IDX:<str>   	Valley Index
	Grid (output)
  -HILL_IDX:<str>     	Hill Index
	Grid (output)
  -SLOPE_IDX:<str>    	Hillslope Index
	Grid (optional output)
  -RADIUS_VALLEY:<str>	Valley Radius
	Floating point
	Minimum: 0.000000
	Default: 1000.000000
  -RADIUS_HILL:<str>  	Hill Radius
	Floating point
	Minimum: 0.000000
	Default: 1000.000000
  -THRESHOLD:<str>    	Elevation Threshold
	Floating point
	Minimum: 0.000000
	Default: 100.000000
  -METHOD:<str>       	Slope Index
	Choice
	Available Choices:
	[0] default
	[1] alternative
	Default: 0