1

Not sure if I've given my problem the right title. By my problem is as follows;

I have a shapefile containing info from a vegetation survey, which is a 50m wide corridor divided into separate polygons by vegetation type and condition. The other shapefile represents a construction corridor, which follows the same alignment as the survey but is only 10m wide.

What I want to do is divide the construction corridor into vegetation types as per the info in the survey shapefile. Is there a function I can use to do this automatically? Or will I have to split this myself using editor and cut polygon tool? It's 150km long so this is going to take a long time to do manually.

2
  • 2
    Perhaps the term you want is "Intersect" or "Union"? desktop.arcgis.com/en/arcmap/latest/tools/analysis-toolbox/… – Vince Jun 6 '17 at 2:11
  • 1
    Or clip @Vince resources.arcgis.com/en/help/main/10.2/index.html#//… depending on whether you want to join attributes from the corridor and fill in empty space. No, Nemz, you don't want to do this manually, not when there are so many options for overlay operators. Note that there is also an Edior::Clip with 'preserve the area that overlaps' in ArcMap; I personally wouldn't do it that way but it's a valid option for simple overlays when you don't want to stop editing and create yet another temporary output. I find that function good for making islands whist editing. – Michael Stimson Jun 6 '17 at 2:43
2

Your problem can be solved automatically using the Intersect tool.

Here is an example:

This is the original inputs - green is the pipeline corridor, red is the veg data: enter image description here

I then run the intersect tool and get this result (yellow polygon). As you can see, the corridor has been removed where there was a gap in the veg data (small green portion showing through): enter image description here

I left a gap in my veg data to illustrate the difference between intersect and union. When using intersect, any gaps in either dataset will result in a gap in the output.

If your veg data has gaps, you should use union instead.

Here is the result of the union tool: enter image description here

To select the features that cover the pipeline corridor, use select by attributes and use the expression FID_PipelineCorridor <> -1. PipelineCorridor is the name of my pipeline corridor layer - use whatever name you have given your corridor layer.

Here is the result of the select - to select the reverse (i.e. to delete records outside the corridor), use 'switch selection' or use FID_PipelineCorridor = -1 in the select by attributes tool:

enter image description here

2
  • 1
    Reference to clip analysis tool help seems sufficient in this case – FelixIP Jun 6 '17 at 3:22
  • @FelixIP I won't take your word for it. Don't see how clip is better for this process. It will perform the same as intersect. There will be data loss if there are any gaps in the veg data - same as intersect. – jbalk Jun 7 '17 at 0:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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