man r.water.outlet () - Watershed basin creation program.


r.water.outlet - Watershed basin creation program.



r.water.outlet help

r.water.outlet drainage=string basin=string easting=x northing=y


Name of input raster map
Name of raster map to contain results
The map E grid coordinates
The map N grid coordinates


r.water.outlet generates a watershed basin from a drainage direction map (from r.watershed) and a set of coordinates representing the outlet point of watershed.

Selected Parameters

Input map: drainage direction. Indicates the "aspect" for each cell. Multiplying positive values by 45 will give the direction in degrees that the surface runoff will travel from that cell. The value -1 indicates that the cell is a depression area. Other negative values indicate that surface runoff is leaving the boundaries of the current geographic region. The absolute value of these negative cells indicates the direction of flow. This map is generated from r.watershed.
Output map: Values of one (1) indicate the watershed basin. Values of zero are not in the watershed basin.
Input value: Easting value of outlet point.
Input value: Northing value of outlet point.


In the context of this program, a watershed basin is the region upstream of an outlet point. Thus, if the user chooses an outlet point on a hill slope, the resulting map will be a thin silver of land representing the overland slope uphill of the point.


d.where, r.watershed, r.topidx


Charles Ehlschlaeger, U.S. Army Construction Engineering Research Laboratory

Last changed: $Date: 2003/05/06 16:30:09 $

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