SAGA-GIS Tool Library Documentation (v9.1.2)

Tool Flow Accumulation (Recursive)

Recursive upward processing of cells for calculation of flow accumulation and related parameters. This set of algorithms processes recursively all upwards connected cells until each cell of the DEM has been processed.

Flow routing methods provided by this tool:


References


Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationGrid, inputELEVATION--
Sink Routes (*)Grid, input, optionalSINKROUTE--
Weights (*)Grid, input, optionalWEIGHTS--
Input for Mean over Catchment (*)Grid, input, optionalVAL_INPUT--
Material for Accumulation (*)Grid, input, optionalACCU_MATERIAL--
Accumulation TargetGrid, inputACCU_TARGET--
Target Areas (*)Grid, input, optionalTARGETS--
OutputFlow AccumulationGrid, outputFLOW--
Mean over CatchmentGrid, outputVAL_MEAN--
Accumulated Material (*)Grid, output, optionalACCU_TOTAL--
Accumulated Material (Left Side) (*)Grid, output, optionalACCU_LEFT--
Accumulated Material (Right Side) (*)Grid, output, optionalACCU_RIGHT--
Flow Path Length (*)Grid, output, optionalFLOW_LENGTHaverage distance that a cell's accumulated flow travelled-
Loss through Negative Weights (*)Grid, output, optionalWEIGHT_LOSSwhen using weights without support for negative flow: output of the absolute amount of negative flow that occurred-
OptionsGrid SystemGrid systemPARAMETERS_GRID_SYSTEM--
Flow Accumulation UnitChoiceFLOW_UNIT-Available Choices:
[0] number of cells
[1] cell area
Default: 1
MethodChoiceMETHOD-Available Choices:
[0] Deterministic 8
[1] Rho 8
[2] Deterministic Infinity
[3] Multiple Flow Direction
Default: 3
ConvergenceFloating pointCONVERGENCEConvergence factor for Multiple Flow Direction Algorithm (Freeman 1991)Minimum: 0.000000
Default: 1.100000
Contour LengthBooleanMFD_CONTOURInclude (pseudo) contour length as additional weighting factor in multiple flow direction routing, reduces flow to diagonal neighbour cells by a factor of 0.71 (s. Quinn et al. 1991 for details).Default: 0
Prevent Negative Flow AccumulationBooleanNO_NEGATIVESwhen using weights: do not transport negative flow, set it to zero instead; useful e.g. when accumulating measures of water balance.Default: 1
(*) optional

Command-line

Usage: saga_cmd ta_hydrology 1 [-ELEVATION <str>] [-SINKROUTE <str>] [-WEIGHTS <str>] [-FLOW <str>] [-VAL_INPUT <str>] [-VAL_MEAN <str>] [-ACCU_MATERIAL <str>] [-ACCU_TARGET <str>] [-ACCU_TOTAL <str>] [-ACCU_LEFT <str>] [-ACCU_RIGHT <str>] [-FLOW_UNIT <str>] [-TARGETS <str>] [-FLOW_LENGTH <str>] [-WEIGHT_LOSS <str>] [-METHOD <str>] [-CONVERGENCE <double>] [-MFD_CONTOUR <str>] [-NO_NEGATIVES <str>]
  -ELEVATION:<str>     	Elevation
	Grid, input
  -SINKROUTE:<str>     	Sink Routes
	Grid, input, optional
  -WEIGHTS:<str>       	Weights
	Grid, input, optional
  -FLOW:<str>          	Flow Accumulation
	Grid, output
  -VAL_INPUT:<str>     	Input for Mean over Catchment
	Grid, input, optional
  -VAL_MEAN:<str>      	Mean over Catchment
	Grid, output
  -ACCU_MATERIAL:<str> 	Material for Accumulation
	Grid, input, optional
  -ACCU_TARGET:<str>   	Accumulation Target
	Grid, input
  -ACCU_TOTAL:<str>    	Accumulated Material
	Grid, output, optional
  -ACCU_LEFT:<str>     	Accumulated Material (Left Side)
	Grid, output, optional
  -ACCU_RIGHT:<str>    	Accumulated Material (Right Side)
	Grid, output, optional
  -FLOW_UNIT:<str>     	Flow Accumulation Unit
	Choice
	Available Choices:
	[0] number of cells
	[1] cell area
	Default: 1
  -TARGETS:<str>       	Target Areas
	Grid, input, optional
  -FLOW_LENGTH:<str>   	Flow Path Length
	Grid, output, optional
  -WEIGHT_LOSS:<str>   	Loss through Negative Weights
	Grid, output, optional
  -METHOD:<str>        	Method
	Choice
	Available Choices:
	[0] Deterministic 8
	[1] Rho 8
	[2] Deterministic Infinity
	[3] Multiple Flow Direction
	Default: 3
  -CONVERGENCE:<double>	Convergence
	Floating point
	Minimum: 0.000000
	Default: 1.100000
  -MFD_CONTOUR:<str>   	Contour Length
	Boolean
	Default: 0
  -NO_NEGATIVES:<str>  	Prevent Negative Flow Accumulation
	Boolean
	Default: 1