topic Re: Calculating slope change in ArcGIS Pro Questions

Calculating slope change

SMangum — Tue, 15 Mar 2022 04:23:21 GMT

I need to find areas of rapid slope change greater than 10º.

I created a slope layer from a DEM.

If I create another slope layer from the original slope layer will I get the change in slope angles between adjacent cells (i.e. the slope of the slope between cells)?

Then I would simply run CON (spatial analysis) or RASTER CALCULATOR to isolate areas of slope change >10º, right?

If not, can anyone tell me how?

I'm using ArcGIS Pro version 2.9.1

Re: Calculating slope change

DanPatterson — Tue, 15 Mar 2022 10:23:28 GMT

curvature? Curvature (Spatial Analyst)—ArcGIS Pro | Documentation

rate of change of slope

How Curvature works—ArcGIS Pro | Documentation

Re: Calculating slope change

SMangum — Tue, 15 Mar 2022 17:53:12 GMT

Huh! I think that's exactly what I need. You're a genius!

If I understand correctly, the input raster would be my DEM_Slope raster. Or am I confused here?

And what constitutes noisy data and how do I know if I have it? High resolution?

My cell size is 10mX10m. Is that high resolution? And if so, should I try the SURFACE PARAMETERS tool instead?

Re: Calculating slope change

DanPatterson — Tue, 15 Mar 2022 19:19:39 GMT

curvature would have the dem as input.

noisy data... depends, you could always run a focal mean over the dem to smooth some of the irregularities if you feel they are present. Experiment

Surface parameters... Surface Parameters (Spatial Analyst)—ArcGIS Pro | Documentation

why not have a run through, it might be revealing to look at the results as well

Re: Calculating slope change

SMangum — Fri, 15 Apr 2022 00:11:40 GMT

Thanks for all your help, Dan! Twenty billion layers later, I discovered the right workflow. Couldn't have done it without ya!

Re: Calculating slope change

DanPatterson — Fri, 15 Apr 2022 00:54:49 GMT

glad it worked out!