Is there any option to SAGA
to calculate the Topographic Wetness Index
?
I have a big area and I tried many times with SAGA, the last time I thought the results was ok (before SAGA would crash or give me a empty raster), however I just noticed that for a small part of my study area the TWI raster is empty.
For the last TWI created in SAGA I decided to calculate the slope also in SAGA, but I still have problems with the file. The area with empty cells is near the right margin of the raster.This is how it looks like (black cells are NODATA cells):
I need to recalculate this asap but I can't find any another solution (in arcgis or qgis).
Edit/Update
I've just saw that I have the same problem in other small areas of the image, that are +/- flat. After overlaying with the SRTM, I can see that when the SRTM value is negative that the TWI cells have NODATA values. I guess this is the reason for the error.