Reading the r.flow manual page suggests that the use of the '-u' (upstream) option allows determination of flowlines and lengths that can be used to delineate the area that would drain to a specific point. Is this correct?
To determine the area flooded if an outlet is plugged would require the inverse of r.drain. That module calculates the area flooded with surface water originating from a specific point; e.g., a hole in a dike or dam. The closest I've seen to do the opposite seems to be r.flow. The quantity of surface water and the rate of accumulation and infiltration into the vadoz zone are not of interest, only the area flooded is needed. The modules listed under the Natural Hazards application page all appear to delineate the area flooded from a point source. Can any of these be used backwards to delineate the area flooded if an outlet is blocked? I'd appreciate pointers and suggestions based on cumulative experience here for appropriate module(s). TIA, Rich _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user