What's going to be the best way to see terrain data (slope/DEM) for a 40 mile pipeline corridor?

Question

I'm somewhat new to the spatial analyst tools. I need to see slopes less than 20% within a 40-mile pipeline corridor about 100 feet wide. It's in Mason County West Virginia (with a tiny piece reaching into putnam) just as an fyi. From what I'm able to come up with it seems I'd be downloading and inserting hundreds of terrain rasters which I'd really rather not do. There has to be an easier way to do this, any suggestions?

Also, I'd like to to only show the terrain within the pipeline polygon, and cut the rest out.

JavierML · Accepted Answer

Hi @jwrrenv ,

I think you got this task well focused, but your task requires either getting the elevation information to point across different segments and then calculating its difference to determine the slope percentage of each segment or, better yet, transforming the DEM to a Slope Raster and then importing this raster values into the point and selecting the segments that have a slope higher than 20%.

In any of the methods, the DEM is needed to do the process and not having them may not possibilitate it. 40 miles is a long stretch, but try figuring out if you can only download the spots that interest you and combine them as a mosaic (try this guide or this other one in German). You can also clip your raster information to the area (you can use a polygon) that you actually want so that less information has to be stored

There could still be an alternative by using Living Atlas, where a Worldwide Elevation Layer is uploaded by ESRI. This actually includes Slope Percent as a Laywe from which you can actaully get the data. This way, as long as you have an Internet connection and a user connected to ArcGIS Online, you can acces the DEM and slope data. However, I don't favourise this method because of 3 reasons:

* You may need access to Image Server, which depends on your licensing contract
* The cell size must be predefined when you upload it in ArcGIS Pro. If you want to set it up for your large extension, the precision will be very limited (I suspect more than 100 m per pixel)
* You can get the data from the raster into the points through tools, but you won't be able to modifiy the raster itself in case you want to do some processing or simply cutting to a certain area if the download times are too slow.

I hope this helps