[GRASS-user] flow map in r.watershed

[Margherita Di Leo]

Hi list!

In the documentation of r.watershed (grass 6.4) I found that it's 
possible to use the following (optional) input map:

flow
Input map: amount of overland flow per cell. This map indicates the 
amount of overland flow units that each cell will contribute to the 
watershed basin model. Overland flow units represent the amount of 
overland flow each cell contributes to surface flow. If omitted, a value 
of one (1) is assumed. The algorithm is D8 flow accumulation.

How is it possible to obtain  this map,  starting  from  a  DEM?

Thank you
 

-- 
Ing. Margherita Di Leo
Ph.D. Student 
Methods and Technologies for Environmental Monitoring
Department of Environmental Engineering and Physics (DIFA)

University of Basilicata 
Campus Macchia Romana
85100 - Potenza 
Italy

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