SAGA-GIS Tool Library Documentation (v7.8.2)

Tool Flow Accumulation (Flow Tracing)

Flow tracing algorithms for calculations of flow accumulation and related parameters. These algorithms trace the flow of each cell in a DEM separately until it finally leaves the DEM or ends in a sink.
The Rho 8 implementation (Fairfield & Leymarie 1991) adopts the original algorithm only for the flow routing and will give quite different results.


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--
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--
OptionsGrid SystemGrid systemPARAMETERS_GRID_SYSTEM--
StepIntegerSTEPFor testing purposes. Only generate flow at cells with step distance (each step row/column).Minimum: 1
Default: 1
Flow Accumulation UnitChoiceFLOW_UNIT-Available Choices:
[0] number of cells
[1] cell area
Default: 1
m_MethodChoiceMETHOD-Available Choices:
[0] Rho 8
[1] Kinematic Routing Algorithm
[2] DEMON
Default: 1
Flow CorrectionBooleanCORRECT-Default: 1
DEMON - Min. DQVFloating pointMINDQVDEMON - Minimum Drainage Quota Volume (DQV) for traced flow tubesMinimum: 0.000000
Maximum: 1.000000
Default: 0.000000
(*) optional

Command-line

Usage: saga_cmd ta_hydrology 2 [-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>] [-STEP <num>] [-FLOW_UNIT <str>] [-METHOD <str>] [-CORRECT <str>] [-MINDQV <double>]
  -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
  -STEP:<num>         	Step
	Integer
	Minimum: 1
	Default: 1
  -FLOW_UNIT:<str>    	Flow Accumulation Unit
	Choice
	Available Choices:
	[0] number of cells
	[1] cell area
	Default: 1
  -METHOD:<str>       	m_Method
	Choice
	Available Choices:
	[0] Rho 8
	[1] Kinematic Routing Algorithm
	[2] DEMON
	Default: 1
  -CORRECT:<str>      	Flow Correction
	Boolean
	Default: 1
  -MINDQV:<double>    	DEMON - Min. DQV
	Floating point
	Minimum: 0.000000
	Maximum: 1.000000
	Default: 0.000000