Will contribute to the watershed basin model. This map indicates the amount of overland flow units that each cell Raster flow map specifies amount of overland flow per cell. That are not NULL and not zero indicate depressions. Option depression specifies the optional map of actualĭepressions or sinkholes in the landscape that are largeĮnough to slow and store surface runoff from a storm event. The elevation map need not be sink-filled because Located within the area of interest must be filled beforehand,Īvoid distortions. NULL (nodata) cells are ignored, zero and negative Option elevation specifies the elevation data on which entireĪnalysis is based. Widely distributed, becoming more similar to SFD. Higher values result in higher convergence, flow is less Values result in higher divergence, flow is more widelyĭistributed. Option convergence specifies convergence factor for MFD. Underestimate are converted to the negative. Set, cells with a flow accumulation value that is likely to be an When -a flag is specified the module will use positive flowĪccumulation even for likely underestimates. This flag will also make the drainage basins look Stream and slope lengths are approximately the same as outputsįrom default surface flow (allows horizontal, vertical, and diagonalįlow of water). MFD is enabled by default.īy -4 flag the user allow only horizontal and vertical flow of Instead of multiple flow direction (MFD). Which allows very large maps to be processed but is slower.įlag -s force the module to use single flow direction (SFD, D8) Setting this flag causes the program to manage memory on disk Without flag -m set, the entire analysis is run in memory Watershed basins, and 2) the LS and S factors of the Revised Universal Create watershed basins map and convert to a vector polygon mapĭESCRIPTION r.watershed generates a set of maps indicating: 1) flowĪccumulation, drainage direction, the location of streams and.Convert r.watershed streams map output to a vector map.Recommended: 5 Default: 5 memory= memory in MB Maximum memory to be used (in MB) Cache size for raster rows Default: 300 threshold= integer Minimum size of exterior watershed basin max_slope_length= float Maximum length of surface flow in map units For USLE accumulation= name Name for output accumulation raster map Number of cells that drain through each cell tci= name Name for output topographic index ln(a / tan(b)) map spi= name Name for output stream power index a * tan(b) Name for output raster map drainage= name Name for output drainage direction raster map Directions numbered from 1 to 8 basin= name Name for output basins raster map stream= name Name for output stream segments raster map half_basin= name Name for output half basins raster map Each half-basin is given a unique value length_slope= name Name for output slope length raster map Slope length and steepness (LS) factor for USLE slope_steepness= name Name for output slope steepness raster map Slope steepness (S) factor for USLE convergence= integer Convergence factor for MFD (1-10) 1 = most diverging flow, 10 = most converging flow. retention= name Name of input raster map with percentages for flow accumulation. All non-NULL and non-zero cells are considered as blocking terrain. Parameters: elevation= name Name of input elevation raster map depression= name Name of input depressions raster map All non-NULL and non-zero cells are considered as real depressions flow= name Name of input raster representing amount of overland flow per cell disturbed_land= name Name of input raster map percent of disturbed land For USLE blocking= name Name of input raster map blocking overland surface flow For USLE.