With regards to the size of DEM, if you can get the command to run it may take several days to finish, this is more than twice the size of the Washington State DEM that took the authors 33 hours in 2003 (Arge, Chase, Halpin, Toma, Urban, Vitter, Wickremesinghe Efficient Flow Computation on Massive Grid Terrain Datasets Geoinformatica Volume 7 Issue 4, December 2003 Pages 283 - 313 ). My mid-2014 computer runs at about twice the speed quoted in the paper. Did you r.recode it to make it smaller? In flat areas you need the data contained after the decimal point to allow the flow a chance to make it down hill, otherwise you can get streams going no where near where they do in real life. I have never tried running r.terraflow on an integer raster, I know that it works on decimal rasters.
-Thayer Date: Mon, 12 Jan 2015 09:59:40 -0200 From: Daniel Victoria <daniel.victo...@gmail.com> To: grass <grass-user@lists.osgeo.org> Subject: [GRASS-user] r.terraflow on massive DEM Message-ID: <CA+irsJjf7xhWgU968D+4+xc2YGJ=_n4xjtp0_weu1zportt...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hi list, I'm trying to run r.terraflow on a very large DEM but I wander if it's __too large__. The region dimensions are: ncol=141114 nrow=140487 Data type = CELL The map is actually a reclass map of a raster that I imported using r.external. When I run r.terraflow I get: r.terraflow elevation=srtm_brasil@PERMANENT filled=srtm_fill direction=flowdir swatershed=sink accumulation=flowacc tci=srtm_tci directory=E:\terraflow_temp WARNING: raster srtm_brasil is of type CELL_TYPE --you should use r.terraflow.short ERROR: [nrows=140487, ncols=141114] dimension_type overflow -- change dimension_type and recompile (Mon Jan 12 09:57:18 2015) Command finished (0 sec) However, I don't have an r.terraflow.short command I'm running Grass 7.0.0beta4 from OsGeo4W Cheers Daniel -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20150112/a27c139f/attachment-0001.html> ------------------------------ _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user End of grass-user Digest, Vol 105, Issue 16 *******************************************
_______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
