SAGA-GIS Tool Library Documentation (v7.8.2)

Tool Relative Heights and Slope Positions

This tool calculates several terrain indices related to the terrain position from a digital elevation model using an iterative approach. You can control the results with three parameters.
The parameter 'w' weights the influence of catchment size on relative elevation (inversely proportional).
The parameter 't' controls the amount by which a maximum in the neighbourhood of a cell is taken over into the cell (considering the local slope between the cells). The smaller 't' and/or the smaller the slope, the more of the maximum value is taken over into the cell. This results in a greater generalization/smoothing of the result. The greater 't' and/or the higher the slope, the less is taken over into the cell and the result will show a more irregular pattern caused by small changes in elevation between the cells.
The parameter 'e' controls the position of relative height maxima as a function of slope. More details about the computational concept can be found in Boehner & Selige (2006).


References


Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationGrid, inputDEM--
OutputSlope HeightGrid, outputHO--
Valley DepthGrid, outputHU--
Normalized HeightGrid, outputNH--
Standardized HeightGrid, outputSH--
Mid-Slope PositonGrid, outputMS--
OptionsGrid SystemGrid systemPARAMETERS_GRID_SYSTEM--
wFloating pointW-Minimum: 0.000000
Default: 0.500000
tFloating pointT-Minimum: 0.000000
Default: 10.000000
eFloating pointE-Minimum: 0.000000
Default: 2.000000

Command-line

Usage: saga_cmd ta_morphometry 14 [-DEM <str>] [-HO <str>] [-HU <str>] [-NH <str>] [-SH <str>] [-MS <str>] [-W <double>] [-T <double>] [-E <double>]
  -DEM:<str> 	Elevation
	Grid, input
  -HO:<str>  	Slope Height
	Grid, output
  -HU:<str>  	Valley Depth
	Grid, output
  -NH:<str>  	Normalized Height
	Grid, output
  -SH:<str>  	Standardized Height
	Grid, output
  -MS:<str>  	Mid-Slope Positon
	Grid, output
  -W:<double>	w
	Floating point
	Minimum: 0.000000
	Default: 0.500000
  -T:<double>	t
	Floating point
	Minimum: 0.000000
	Default: 10.000000
  -E:<double>	e
	Floating point
	Minimum: 0.000000
	Default: 2.000000