3

I need help from stackexchange because of a DEM correction problem...

I have a DEM with a 5 meters resolution where one of the main river is cut by a large highway. In order to delete that topology error I'm looking for a method for burning the river in the DEM.

After looking at tutorials I've tried "r.carve" (additionnal stream depth = 10 meters) but even thought it happened to have corrected my DEM, the flow accumulation in this area is very discontinuous...

What is the problem here?

r.carve

cathment area

Improve this question
2
  • 1
    I find looking at your DEM in hillshade mode can help to see if the carve function worked. I usually just use fill sinks because it doesn't really matter in my analysis but it looks like there is a SAGA alg called Sink Removal that may do what you want as an alternative to r.carve.
    – Baswein
    Commented Jun 4, 2020 at 17:14
  • 1
    @Baswein: I used the fill sinks function before running "r.carve" but actually I should have done it after ! I completely forgot that I had to renew that process after having modified my DEM ! Thank you for the hint !
    – Linda
    Commented Jun 4, 2020 at 21:04

1 Answer 1

Reset to default
3

If I were you I would rather use Fill sinks (Wang & Lui) after using r.carve !

Make also sure that your vector and raster layers have the same projection.

http://www.saga-gis.org/saga_tool_doc/2.1.3/ta_preprocessor_4.html

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.