>> I'm not seeing why this error is generated, and need to understand why so >> I can model a dozen or so small basins. > > I checked whether the weight and weighted flow accumulation maps were >defective, but they don't appear to be. In the GUI dieplay window I display >dem10m.avg (the basic elevation map), dem10m.acc (the flow accumulation >map), weight (the calculated weighing map), and dem10m.acc.weighted. They >all overlap.
from the manual page: https://svn.osgeo.org/grass/grass-addons/grass6/raster/r.stream.extract/description.html accumulation Input map, optional: Accumulation values of the provided accumulation map are used and not calculated from the input elevation map. If accumulation is given, elevation must be exactly the same map used to calculate accumulation. If accumulation was calculated with r.terraflow, the filled elevation output of r.terraflow must be used. Further on, the current region's resolution should be identical to the accumulation map. Flow direction is first calculated from elevation and then adjusted to accumulation. It is not necessary to provide accumulation as the number of cells, it can also be the optionally adjusted or weighed total contributing area in square meters or any other unit. - is the elevation exactly the same map used to calculate accumulation? - is the current region's resolution identical to the accumulation map? Helmut ----- best regards Helmut -- View this message in context: http://osgeo-org.1560.n6.nabble.com/r-stream-extract-Syntax-Problem-tp4690890p4692228.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user