SAGA-GIS Module Library Documentation (v2.2.2)

Module Stream Power Index

Calculation of stream power index based on slope and specific catchment area (SCA).
SPI = SCA * tan(Slope)

References:

Moore, I.D., Grayson, R.B., Ladson, A.R. (1991):
'Digital terrain modelling: a review of hydrogical, geomorphological, and biological applications'
Hydrological Processes, Vol.5, No.1

Parameters

 NameTypeIdentifierDescriptionConstraints
InputSlopeGrid (input)SLOPE--
Catchment AreaGrid (input)AREA--
OutputStream Power IndexGrid (output)SPI--
OptionsArea ConversionChoiceCONV-Available Choices:
[0] no conversion (areas already given as specific catchment area)
[1] 1 / cell size (pseudo specific catchment area)
Default: 0

Command-line

Usage: saga_cmd ta_hydrology 21 [-SLOPE <str>] [-AREA <str>] [-SPI <str>] [-CONV <str>]
  -SLOPE:<str>	Slope
	Grid (input)
  -AREA:<str> 	Catchment Area
	Grid (input)
  -SPI:<str>  	Stream Power Index
	Grid (output)
  -CONV:<str> 	Area Conversion
	Choice
	Available Choices:
	[0] no conversion (areas already given as specific catchment area)
	[1] 1 / cell size (pseudo specific catchment area)
	Default: 0