I am trying to prepare a raster file which i could use with SAGA processing tools for hydrologic analysis in QGIS. I am using Win 7, 32 bit, QGIS 2.14.20 and SAGA 2.3.2 I downloaded the srtm file in hgt format from the net. After i converted the file to a Geotiff while reducing the size with the QGIS clipper tool. I changed as well the CRS to UTM.
I have seen on this answer to a rather similiar question: QGIS: Saga Channel network: how to prepare SRTM data that i should try the Fill sinks under SAGA. But even this function doesn´t work with my raster. I get the output, just as for the other tools, that: the layer(s) couldn´t be created. I am quite sure that my QGIS/ SAGA setup is fine, because i tried all operations with a Raster DEM provided from QGIS and the SAGA tools worked all right and prepared what i am looking for. Therefore i suppose there must be a mistake in my raster file. I tried to change pixel value <=0 to no data value with the raster calulator but without success! I would be very glad if someone can provide a direction for a solution.
As decribed above i start with the SRTM hgt file. Step 1: Save the hgt as a Geotiff and change of CRS to UTM with the right click menu under "save as"
Step 2: I created a polygon vector mask layer and used the QGIS clipper under Raster - Extraction - Clipper:
The raster file i get has the following metadata: ]
Step 4: I tried using this layer with different hydrologic processing tools, SAGA and GRASS under QGIS. Here an example for GRASS using the
This is the error i will get for unfortunately all the tools i tried to use: