Upslope Area

Author: O.Conrad (c) 2001
Menu: Terrain Analysis | Hydrology | Flow Accumulation

Description

This tool allows you to specify target cells, for which the upslope contributing area shall be identified. The result will give for each cell the percentage of its flow that reaches the target cell(s). _______ Interactive version (left mouse clicks will trigger the calculation for the selected cell).

References

Freeman, G.T. (1991): Calculating catchment area with divergent flow based on a regular grid. Computers and Geosciences, 17:413-22.
O'Callaghan, J.F. & Mark, D.M. (1984): The extraction of drainage networks from digital elevation data. Computer Vision, Graphics and Image Processing, 28:323-344.
Qin, C. Z., Zhu, A. X., Pei, T., Li, B. L., Scholten, T., Behrens, T. & Zhou, C. H. (2011): An approach to computing topographic wetness index based on maximum downslope gradient. Precision Agriculture, 12(1), 32-43. ResearchGate.
Quinn, P.F., Beven, K.J., Chevallier, P. & Planchon, O. (1991): The prediction of hillslope flow paths for distributed hydrological modelling using digital terrain models. Hydrological Processes, 5:59-79. ResearchGate.
Seibert, J. & McGlynn, B. (2007): A new triangular multiple flow direction algorithm for computing upslope areas from gridded digital elevation models. Water Resources Research, Vol. 43, W04501,
C++ implementation in SAGA by Thomas Grabs (c) 2007, contact: thomas.grabs@natgeo.su.se, jan.seibert@natgeo.su.se. Wiley.
Tarboton, D.G. (1997): A new method for the determination of flow directions and upslope areas in grid digital elevation models. Water Resources Research, Vol.33, No.2, p.309-319. Wiley.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Elevation	grid, input	`ELEVATION`	-	-
Input	Sink Routes	grid, input, optional	`SINKROUTE`	-	-
Output	Upslope Area	grid, output	`AREA`	-	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Method	choice	`METHOD`	-	Available Choices: [0] Deterministic 8 [1] Deterministic Infinity [2] Multiple Flow Direction [3] Multiple Triangular Flow Directon [4] Multiple Maximum Downslope Gradient Based Flow Directon Default: 2
	Convergence	floating point number	`CONVERGE`	Convergence factor for Multiple Flow Direction Algorithm (Freeman 1991). Applies also to the Multiple Triangular Flow Directon Algorithm.	Minimum: 0.001000 Default: 1.100000
	Contour Length	boolean	`MFD_CONTOUR`	Include (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

Command Line


Usage: saga_cmd ta_hydrology 3 [-ELEVATION ] [-SINKROUTE ] [-AREA ] [-METHOD ] [-CONVERGE ] [-MFD_CONTOUR ]
  -ELEVATION:  	Elevation
	grid, input
  -SINKROUTE:  	Sink Routes
	grid, input, optional
  -AREA:       	Upslope Area
	grid, output
  -METHOD:     	Method
	choice
	Available Choices:
	[0] Deterministic 8
	[1] Deterministic Infinity
	[2] Multiple Flow Direction
	[3] Multiple Triangular Flow Directon
	[4] Multiple Maximum Downslope Gradient Based Flow Directon
	Default: 2
  -CONVERGE:	Convergence
	floating point number
	Minimum: 0.001000
	Default: 1.100000
  -MFD_CONTOUR:	Contour Length
	boolean
	Default: 0