Tool CIT Index

The tool allows one to calculate a variant of the Stream Power Index, which was introduced to detect channel heads (channel initiation) based on a drainage area-slope threshold. The Channel Initiation Threshold (CIT) index is calculated as: CIT = SCA * tan(Slope)^2

References

Montgomery, D.R., Dietrich, W.E. (1989): Source areas, drainage density and channel initiation. Water Resources Research 25, p.1907-1918.
Montgomery, D.R., Foufoula-Georgiou, E. (1993): Channel network source representation using digital elevation models. Water Resources Research 29, p.3925-3934.

Author: V. Wichmann (c) 2021
Menu: Terrain Analysis|Hydrology|Topographic Indices

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Slope	grid, input	`SLOPE`	The slope grid [radians].	-
Input	Catchment Area	grid, input	`AREA`	The catchment area grid [map unitsz^2].	-
Output	CIT Index	grid, output	`CIT`	The Channel Initiation Threshold index.	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
Options	Area Conversion	choice	`CONV`	-	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 31 [-SLOPE <str>] [-AREA <str>] [-CIT <str>] [-CONV <str>]
  -SLOPE:<str>	Slope
	grid, input
  -AREA:<str> 	Catchment Area
	grid, input
  -CIT:<str>  	CIT 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