First of all: Windows 8.1 QGIS 2.8.2 Wien

I used the GRASS module r.watershed to delineate watersheds and get flows with a DEM. It worked fine so everything is OK so far. But now what I want to do is to export these new GRASS raster layers to Geotiff, and later to vector polygons or lines, in case of flows. On the one hand, I tried to use the GRASS module r.out.gdal.gtiff (Export raster to GeoTiff) but the problem is that the file format it exports is NOT Geotiff! (I don't know why?) And on the other hand, I try to right-click on the GRASS raster file and choose "save as" then I choos Geotiff format, ok, and.... Crash... Finally, I chose to do the same "save as" only the view area, and it works, but the Geotiff I get is totally grey, can't find the way to see the polygons I got when it was the GRASS raster. I don't know what am I doing wrong... :( (Screenshot: "basinsmoshi"screenshot qgis problem is the new .tiff file, completely grey).

I wish anyone could tell me how to save this GRASS raster file into a Tiff and then into a vector file, so I can edit the polygons, etc...

The answer by @xunilk didn't work. Let me try to explain with more detail. First: I already did the watershed delineation with GRASS using r.watershed: enter image description here

Second: I tried what you said, r.out.gdal with the same parameters. enter image description here

Finally, I ran it, successfully finished, but... when I load the new raster, it simply has no content (values are "nan nan"):

enter image description here

So again, I am sure I am doing something wrong :( but I don't know what it is. The only thing I want is to have these watersheds as polygons in a .shp file, if you know about any other method?

  • Welcome to gis.stackexchange! Please edit the title of your question to include enough information for future visitors to be able to find this thread when looking for the same problem.
    – underdark
    Sep 3, 2015 at 19:26

1 Answer 1


Try r.out.gdal. First, at the layer properties, you can see the raster data type of the original raster. Afterward, at the Modules List of next image, you have the parameters used by me for exporting the raster as *.tif.

enter image description here

At the next image you can see that the process was successfully finished.

enter image description here

The resulting raster (it was as I expected; without the original GRASS renderer):

enter image description here

  • Ok @xunilk thanks but it didn't work:( I am going to try to explain what happened with more detail Sep 3, 2015 at 18:08

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