Tool Overland Flow Distance to Channel Network
This tool calculates overland flow distances to a channel network based on gridded digital elevation data and channel network information. The flow algorithm may be either Deterministic 8 (O'Callaghan & Mark 1984) or Multiple Flow Direction (Freeman 1991). Sediment Delivery Rates (SDR) according to Ali & De Boer (2010) can be computed optionally.
References
- Ali, K. F., De Boer, D. H. (2010): Spatially distributed erosion and sediment yield modeling in the upper Indus River basin. Water Resources Research, 46(8), W08504 doi:10.1029/2009WR008762.
- Freeman, G.T. (1991): Calculating catchment area with divergent flow based on a regular grid. Computers and Geosciences, 17:413-22. doi:10.1016/0098-3004(91)90048-I.
- Nobre, A.D., Cuartas, L.A., Hodnett, M., Renno, C.D., Rodrigues, G., Silveira, A., Waterloo, M., Saleska S. (2011): Height Above the Nearest Drainage - a hydrologically relevant new terrain model. Journal of Hydrology, Vol. 404, Issues 1-2, pp. 13-29, ISSN 0022-1694, 10.1016/j.jhydrol.2011.03.051. doi:10.1016/j.jhydrol.2011.03.051.
- 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. doi:10.1016/S0734-189X(84)80011-0.
- Author: O.Conrad (c) 2001-14
- Menu: Terrain Analysis|Channels
Parameters
Name | Type | Identifier | Description | Constraints | |
---|---|---|---|---|---|
Input | Elevation | Grid, input | ELEVATION | A grid that contains elevation data. | - |
Channel Network | Grid, input | CHANNELS | A grid providing information about the channel network. It is assumed that no-data cells are not part of the channel network. Vice versa all others cells are recognised as channel network members. | - | |
Preferred Routing (*) | Grid, input, optional | ROUTE | Downhill flow is bound to preferred routing cells, where these are not no-data. Helps to model e.g. small ditches, that are not well represented in the elevation data. | - | |
Fields (*) | Grid, input, optional | FIELDS | If set, output is given about the number of fields a flow path visits downhill. For D8 only. | - | |
Manning-Strickler Coefficient (*) | Grid, input, optional | FLOW_K | Manning-Strickler coefficient for flow travel time estimation (reciprocal of Manning's Roughness Coefficient) | - | |
Flow Depth (*) | Grid, input, optional | FLOW_R | flow depth [m] for flow travel time estimation | - | |
Output | Overland Flow Distance | Grid, output | DISTANCE | The overland flow distance in map units. It is assumed that the (vertical) elevation data use the same units as the (horizontal) grid coordinates. | - |
Vertical Overland Flow Distance | Grid, output | DISTVERT | This is the vertical component of the overland flow | - | |
Horizontal Overland Flow Distance | Grid, output | DISTHORZ | This is the horizontal component of the overland flow | - | |
Flow Travel Time (*) | Grid, output, optional | TIME | flow travel time to channel expressed in hours based on Manning's Equation | - | |
Sediment Yield Delivery Ratio (*) | Grid, output, optional | SDR | This is the horizontal component of the overland flow | - | |
Fields Visited | Grid, output | PASSES | Number of fields a flow path visits downhill starting at a cell. For D8 only. | - | |
Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
Flow Algorithm | Choice | METHOD | Choose a flow routing algorithm that shall be used for the overland flow distance calculation: - D8 - MFD | Available Choices: [0] D8 [1] MFD Default: 1 | |
Boundary Cells | Boolean | BOUNDARY | Take cells at the boundary of the DEM as channel. | Default: 0 | |
Beta | Floating point | FLOW_B | catchment specific parameter for sediment delivery ratio calculation | Minimum: 0.000000 Default: 1.000000 | |
Default | Floating point | FLOW_K_DEFAULT | default value if no grid has been selected | Minimum: 0.000000 Default: 20.000000 | |
Default | Floating point | FLOW_R_DEFAULT | default value if no grid has been selected | Minimum: 0.000000 Default: 0.050000 | |
(*) optional |
Command-line
Usage: saga_cmd ta_channels 4 [-ELEVATION <str>] [-CHANNELS <str>] [-ROUTE <str>] [-DISTANCE <str>] [-DISTVERT <str>] [-DISTHORZ <str>] [-TIME <str>] [-SDR <str>] [-FIELDS <str>] [-PASSES <str>] [-METHOD <str>] [-BOUNDARY <str>] [-FLOW_B <double>] [-FLOW_K <str>] [-FLOW_K_DEFAULT <double>] [-FLOW_R <str>] [-FLOW_R_DEFAULT <double>] -ELEVATION:<str> Elevation Grid, input -CHANNELS:<str> Channel Network Grid, input -ROUTE:<str> Preferred Routing Grid, input, optional -DISTANCE:<str> Overland Flow Distance Grid, output -DISTVERT:<str> Vertical Overland Flow Distance Grid, output -DISTHORZ:<str> Horizontal Overland Flow Distance Grid, output -TIME:<str> Flow Travel Time Grid, output, optional -SDR:<str> Sediment Yield Delivery Ratio Grid, output, optional -FIELDS:<str> Fields Grid, input, optional -PASSES:<str> Fields Visited Grid, output -METHOD:<str> Flow Algorithm Choice Available Choices: [0] D8 [1] MFD Default: 1 -BOUNDARY:<str> Boundary Cells Boolean Default: 0 -FLOW_B:<double> Beta Floating point Minimum: 0.000000 Default: 1.000000 -FLOW_K:<str> Manning-Strickler Coefficient Grid, input, optional -FLOW_K_DEFAULT:<double> Default Floating point Minimum: 0.000000 Default: 20.000000 -FLOW_R:<str> Flow Depth Grid, input, optional -FLOW_R_DEFAULT:<double> Default Floating point Minimum: 0.000000 Default: 0.050000