[GRASS-user] extracting features from DEM: how big DEM?

Markus Metz markus.metz.giswork at googlemail.com
Thu Jul 23 02:32:10 EDT 2009

The upper computational limit of r.watershed and r.terraflow (not 100% 
sure here, may be higher) is 2,147,483,647 cells. It will take a long 
time, r.watershed -m much longer than r.terraflow, but both modules will 
do it. It will be many hours if not some days for a region with 
2,147,483,647 cells, so the question is how long you want to wait.

Markus M

Milton Cezar Ribeiro wrote:
> Dear all,
> I am organizing a very large DEM for a region of interest,
> and would like to know from our colleagues what is your
> experience with features extraction from large DEM.
> What was your highest (rows and cols) DEM that
> you handled on grass? I will need to extract features
> using r.watershed, r.flor, w.terraflor, and the I need
> to extract several features (may be 10) from my final
> (not yet ready) DEM.
> Thanks in advance for the help
> miltinho
> brazil=toronto
> ------------------------------------------------------------------------
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user

More information about the grass-user mailing list