topic Re: Getting elevation maps for individual polygons in ArcGIS Pro Questions

Getting elevation maps for individual polygons

MaxHamilton — Fri, 19 Jan 2024 21:39:29 GMT

I have a polygon feature class for a watershed map and I wanted to have an individual elevation map for each polygon. It seems like the easiest way to do this is the Split Raster geoprocessing tool, but every time I use it I get the error 999999. I have tried every trouble shooting method for this error that I have run across on the internet (the raster and feature class are the same spatial reference, I've rebooted everything multiple times, repaired geometry, etc). Is there another way I can achieve this process without that tool other than reclipping the DEM raster for each polygon?

Re: Getting elevation maps for individual polygons

DanPatterson — Fri, 19 Jan 2024 22:19:20 GMT

a screen grab of the tool inputs would help.

The outputs are to go to a folder, so what output type are you specifying?

Re: Getting elevation maps for individual polygons

RonaldHaug — Sat, 20 Jan 2024 07:48:34 GMT

Hi Max,

There are a number of ways one can visualize what you want. Here's one way.

If your DEM is a large file you may want to extract by mask to a map extent, just to keep your file size tidy. You can create a map extent by creating a rectangular polygon feature class by right-clicking your .gdb in your catalog pane. Once it's loaded onto your Contents pane, click on it, go to edit, create, and then make the map extent. Then hit the Save icon.

Be sure to save your project after each use of your tools. It's a good practice and frees up memory. Operations with rasters like Digital Elevation Models use the most memory.

From there you can run the Contour tool first and then clip the contour line to your respective polygons.

To access these tools use the command search bar at the top center of the screen. Contour requires a Spatial Analyst subscription. Check in Project (top left), Licensing, Esri Extensions to see if you have it.

You can search any of these tools in greater detail on ArcGIS Pro help.

https://pro.arcgis.com/en/pro-app/latest/help/main/welcome-to-the-arcgis-pro-app-help.htm

Re: Getting elevation maps for individual polygons

MaxHamilton — Mon, 22 Jan 2024 17:59:34 GMT

I appreciate the suggestions, turns out my issue was very small pixel sized polygons were unintentionally created by a previous tool in my feature class that was probably too small for the split to work. Once those were cleaned up it worked great.

Re: Getting elevation maps for individual polygons

DanPatterson — Mon, 22 Jan 2024 20:33:20 GMT

you might want to use regiongroup and nibble to remove those errant remnants

Region Group (Spatial Analyst)—ArcGIS Pro | Documentation

Nibble (Spatial Analyst)—ArcGIS Pro | Documentation

How Nibble works—ArcGIS Pro | Documentation

or other spatial filters like the majority filter or...

Generalizing zones with Expand and Shrink—ArcGIS Pro | Documentation