topic Re: I need some help extracting gully erosion features from a DEM in Data Management Questions

I need some help extracting gully erosion features from a DEM

GeospatialTechnology — Mon, 28 Oct 2013 10:06:15 GMT

Hello i was wondering i anyone here is experienced in geomorphometry?

I have a DEM dataset of an area of landscape that is heavily eroded with gully features.

What I would like to try to automatically map these features. So for example a polygon layer would be created showing where these features are.

Other things I would like to try include calculating the area of gullying compared to the rest of the DEM.

Also if there was someway to calculate the total volume of surface material lost to gullying that would be amazing

Re: I need some help extracting gully erosion features from a DEM

GeospatialTechnology — Mon, 28 Oct 2013 13:03:04 GMT

Further to this I was wondering if there was means to model erosion/deposition within a watershed?

Re: I need some help extracting gully erosion features from a DEM

michaelcollins1 — Mon, 28 Oct 2013 13:27:40 GMT

Would the Slope tool help you to identify the gullies? Also, the Cut Fill tool would help find the volume difference if you had "before and after" DEMs.

Re: I need some help extracting gully erosion features from a DEM

GeospatialTechnology — Mon, 28 Oct 2013 14:52:47 GMT

Thanks Michael. I've already been playing around with slope as well as standard deviation filters and these give a really good result of where each of the features are. I guess what i'm trying to do is to map the extent of gullying across the DEM if that makes sense? I guess I can just reclass to include all slopes above a certain angle and that will do the trick.

I'll give the cut fill tool a go as well as I think i've just found a way to create a rough 'before' surface.