> Each of my two current projects requiring spatial analyses involve >multiple 12-digit HUC basins (sub-watersheds). I need to separately analyze >each sub-watershed to determine differences. I can clip vector maps by >interescting the lines and the sub-watershed boundaries. But, my >understanding is that raster maps cannot be subdivided in the same way so >we need to generate masks for the areas to be included in each analysis. >That is, r.* modules are applied to only those portions of the overall DEM >map within the mask. > > If there is a module, or process (perhaps applying r.mapcalc for the map >algebra), that will allow me to create separate DEMs for each sub-watershed >(or other analytical unit) I would prefer to work with each of those rather >than need to run r.mask for each different basin. I'd like to learn how to >sub-set raster DEMs so each basin is a separate map rather than a masked >portion.
if the (sub-)watershed are already given, maybe the easiest way to define the region extent for raster processing of your interest is using g.region [1]: 'g.region -a rast=yourdem align=yourdem vect=subbasin1' raster processing 'g.region -a rast=yourdem align=yourdem vect=subbasin2' raster processing etc. no need to create separate DEMs for each sub-watershed (or other analytical units) or masks. Helmut [1] http://grass.osgeo.org/grass64/manuals/html64_user/g.region.html ----- best regards Helmut -- View this message in context: http://osgeo-org.1560.n6.nabble.com/r-stream-extract-Syntax-Problem-tp4690890p4695975.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
