DEM File “not found” Error when running r.watershed with Processing Toolbox in QGIS 3.4.2 with GRASS

Question

I have downloaded a DEM from the NASA server with "SRTM Downloader".

I want to find the watershed area, so I run the "r.watershed" function form the Processing Toolbox.

However, I got a multi- "not fond" errors when I run it (see the full log below)

I saved the DEM on the Desktop, but it did not help. What do I need to do in order to run this process properly?

Full log processing algorithm

Algorithm 'r.watershed' starting… Input parameters: { '-4' : False, '-a' : False, '-b' : False, '-m' : False, '-s' : False, 'GRASS_RASTER_FORMAT_META' : '', 'GRASS_RASTER_FORMAT_OPT' : '', 'GRASS_REGION_CELLSIZE_PARAMETER' : 0, 'GRASS_REGION_PARAMETER' : None, 'accumulation' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/a710f43c24d4455aafd3ea7d82d33b29/accumulation.tif', 'basin' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/23a8c4140274424289ae8bc183275ab3/basin.tif', 'blocking' : None, 'convergence' : 5, 'depression' : None, 'disturbed_land' : None, 'drainage' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/13754e04e06942f9b51292b2a13631dc/drainage.tif', 'elevation' : 'C:/Users/nitza/AppData/Local/Temp/N27E086.hgt', 'flow' : None, 'half_basin' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/79e4452449a04740a5360a6f1503fa57/half_basin.tif', 'length_slope' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/e5eaddcab7fa41e4a62d459ffb40a1ea/length_slope.tif', 'max_slope_length' : None, 'memory' : 300, 'slope_steepness' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/5a3b13f0b3b647a89dfe27c0bc391175/slope_steepness.tif', 'spi' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/c6dbe7a35861445b82d4186e3ffb4bd9/spi.tif', 'stream' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/3c624b66e44e447f91252f08949efbe1/stream.tif', 'tci' : 'C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/e38ef9fd14d341b5b7a297f0a7bec0df/tci.tif', 'threshold' : None }

g.proj -c proj4="+proj=longlat +datum=WGS84 +no_defs" r.external input="C:\Users\nitza\AppData\Local\Temp\N27E086.hgt" band=1 output="rast_5c18fd4fbdfad7" --overwrite -o g.region n=28.000138888888888 s=26.99986111111111 e=87.0001388888889 w=85.99986111111112 res=0.000277777777777779 r.watershed elevation=rast_5c18fd4fbdfad7 convergence=5 memory=300 accumulation=accumulation629c106700f245b6b88447f28cabb2cb drainage=drainage629c106700f245b6b88447f28cabb2cb basin=basin629c106700f245b6b88447f28cabb2cb stream=stream629c106700f245b6b88447f28cabb2cb half_basin=half_basin629c106700f245b6b88447f28cabb2cb length_slope=length_slope629c106700f245b6b88447f28cabb2cb slope_steepness=slope_steepness629c106700f245b6b88447f28cabb2cb tci=tci629c106700f245b6b88447f28cabb2cb spi=spi629c106700f245b6b88447f28cabb2cb --overwrite g.region raster=accumulation629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="accumulation629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\a710f43c24d4455aafd3ea7d82d33b29\accumulation.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=drainage629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="drainage629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\13754e04e06942f9b51292b2a13631dc\drainage.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=basin629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="basin629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\23a8c4140274424289ae8bc183275ab3\basin.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=stream629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="stream629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\3c624b66e44e447f91252f08949efbe1\stream.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=half_basin629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="half_basin629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\79e4452449a04740a5360a6f1503fa57\half_basin.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=length_slope629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="length_slope629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\e5eaddcab7fa41e4a62d459ffb40a1ea\length_slope.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=slope_steepness629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="slope_steepness629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\5a3b13f0b3b647a89dfe27c0bc391175\slope_steepness.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=tci629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="tci629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\e38ef9fd14d341b5b7a297f0a7bec0df\tci.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite g.region raster=spi629c106700f245b6b88447f28cabb2cb r.out.gdal -t -m input="spi629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\c6dbe7a35861445b82d4186e3ffb4bd9\spi.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite Cleaning up temporary files... Starting GRASS GIS... WARNING: Concurrent mapset locking is not supported on Windows Executing ... C:\PROGRA~1\QGIS3~1.4\bin>chcp 1252 1>NUL C:\PROGRA~1\QGIS3~1.4\bin>g.proj -c proj4="+proj=longlat +datum=WGS84 +no_defs" Default region was updated to the new projection, but if you have multiple mapsets g.region -d should be run in each to update the region from the default Projection information updated C:\PROGRA~1\QGIS3~1.4\bin>r.external input="C:\Users\nitza\AppData\Local\Temp\N27E086.hgt" band=1 output="rast_5c18fd4fbdfad7" --overwrite -o Over-riding projection check Reading band 1 of 1... r.external complete. Link to raster map created. C:\PROGRA~1\QGIS3~1.4\bin>g.region n=28.000138888888888 s=26.99986111111111 e=87.0001388888889 w=85.99986111111112 res=0.000277777777777779 C:\PROGRA~1\QGIS3~1.4\bin>r.watershed elevation=rast_5c18fd4fbdfad7 convergence=5 memory=300 accumulation=accumulation629c106700f245b6b88447f28cabb2cb drainage=drainage629c106700f245b6b88447f28cabb2cb basin=basin629c106700f245b6b88447f28cabb2cb stream=stream629c106700f245b6b88447f28cabb2cb half_basin=half_basin629c106700f245b6b88447f28cabb2cb length_slope=length_slope629c106700f245b6b88447f28cabb2cb slope_steepness=slope_steepness629c106700f245b6b88447f28cabb2cb tci=tci629c106700f245b6b88447f28cabb2cb spi=spi629c106700f245b6b88447f28cabb2cb --overwrite Sorry, if any of the following options are set: basin, stream, half_basin, length_slope, or slope_steepness you MUST provide a value for the basin threshold parameter. Calculates hydrological parameters and RUSLE factors. Usage: r.watershed [-s4mab] elevation=name [depression=name] [flow=name] [disturbed_land=name] [blocking=name] [threshold=value] [max_slope_length=value] [accumulation=name] [tci=name] [spi=name] [drainage=name] [basin=name] [stream=name] [half_basin=name] [length_slope=name] [slope_steepness=name] [convergence=value] [memory=value] [--overwrite] [--help] [--verbose] [--quiet] [--ui] Flags: -s SFD (D8) flow (default is MFD) -4 Allow only horizontal and vertical flow of water -m Enable disk swap memory option: Operation is slow -a Use positive flow accumulation even for likely underestimates -b Beautify flat areas Parameters: elevation Name of input elevation raster map depression Name of input depressions raster map flow Name of input raster representing amount of overland flow per cell disturbed_land Name of input raster map percent of disturbed land blocking Name of input raster map blocking overland surface flow threshold Minimum size of exterior watershed basin max_slope_length Maximum length of surface flow in map units accumulation Name for output accumulation raster map tci Name for output topographic index ln(a / tan(b)) map spi Stream power index a * tan(b) drainage Name for output drainage direction raster map basin Name for output basins raster map stream Name for output stream segments raster map half_basin Name for output half basins raster map length_slope Name for output slope length raster map slope_steepness Name for output slope steepness raster map convergence Convergence factor for MFD (1-10) default: 5 memory Maximum memory to be used with -m flag (in MB) default: 300 C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=accumulation629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="accumulation629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\a710f43c24d4455aafd3ea7d82d33b29\accumulation.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=drainage629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="drainage629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\13754e04e06942f9b51292b2a13631dc\drainage.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=basin629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="basin629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\23a8c4140274424289ae8bc183275ab3\basin.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=stream629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="stream629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\3c624b66e44e447f91252f08949efbe1\stream.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=half_basin629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="half_basin629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\79e4452449a04740a5360a6f1503fa57\half_basin.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=length_slope629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="length_slope629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\e5eaddcab7fa41e4a62d459ffb40a1ea\length_slope.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=slope_steepness629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="slope_steepness629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\5a3b13f0b3b647a89dfe27c0bc391175\slope_steepness.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=tci629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="tci629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\e38ef9fd14d341b5b7a297f0a7bec0df\tci.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>g.region raster=spi629c106700f245b6b88447f28cabb2cb ERROR: Raster map not found C:\PROGRA~1\QGIS3~1.4\bin>r.out.gdal -t -m input="spi629c106700f245b6b88447f28cabb2cb" output="C:\Users\nitza\AppData\Local\Temp\processing_4c30c0c423384fee90bc3b7173b739cd\c6dbe7a35861445b82d4186e3ffb4bd9\spi.tif" format="GTiff" createopt="TFW=YES,COMPRESS=LZW" --overwrite ERROR: Raster map or group not found C:\PROGRA~1\QGIS3~1.4\bin>exit Execution of finished. Cleaning up temporary files... Press any key to continue . . . Execution completed in 3.56 seconds Results: {'accumulation': , 'basin': , 'drainage': , 'half_basin': , 'length_slope': , 'slope_steepness': , 'spi': , 'stream': , 'tci': }

Loading resulting layers The following layers were not correctly generated.

• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/13754e04e06942f9b51292b2a13631dc/drainage.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/23a8c4140274424289ae8bc183275ab3/basin.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/3c624b66e44e447f91252f08949efbe1/stream.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/5a3b13f0b3b647a89dfe27c0bc391175/slope_steepness.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/79e4452449a04740a5360a6f1503fa57/half_basin.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/a710f43c24d4455aafd3ea7d82d33b29/accumulation.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/c6dbe7a35861445b82d4186e3ffb4bd9/spi.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/e38ef9fd14d341b5b7a297f0a7bec0df/tci.tif
• C:/Users/nitza/AppData/Local/Temp/processing_4c30c0c423384fee90bc3b7173b739cd/e5eaddcab7fa41e4a62d459ffb40a1ea/length_slope.tif

You can check the 'Log Messages Panel' in QGIS main window to find more information about the execution of the algorithm.

Answer 1

I think that the problem is the missing threshold parameter. In the GUI window it appears as "optional" since there are some simple uses for r.watershed that do not require a threshold. But for any normal use of this module you must provide the threshold.

It is worth to notice that in the QGIS GUI, the parameter is not mentioned at all by its original name threshold of the GRASS command, but it is the value of the box under the text Minimum size of exterior watershed basin [optional].

In your posted error message, somewhere in the middle, it says:

"Sorry, if any of the following options are set: basin, stream, half_basin, length_slope, or slope_steepness you MUST provide a value for the basin threshold parameter."

HTH