topic Re: Quantifying overlapping polygons in Geoprocessing Questions

Quantifying overlapping polygons

CristoforosRomanos — Tue, 11 Aug 2026 07:25:23 GMT

Hello. I’m following up from a recent post regarding the quantification of polygons (features) that overlap. As I currently understand it, the Count Overlapping Features (COF) tool is a misnomer since the result enumerates the number of overlaps rather than the number of features which overlap. So currently, using COF, 5 different overlapping polygons could produce a count of 3, whereas I am interested in how many polygons overlap to create a distinct cluster (5 in this example). To clarify: I would like to quantify the number of polygons (buffer areas surrounding buildings in this specific case) which intersect with each other rather than count the number of times different polygons happen to overlap. I have attached a screenshot of the output I wish to achieve (produced by manually selecting and changing the attribute of each polygon that overlaps to form a distinct cluster). Is there some automated method which could provide me with desired results?

Re: Quantifying overlapping polygons

JonathanMcD — Tue, 11 Aug 2026 07:36:27 GMT

@CristoforosRomanos

Not that I've used the tool in ages, usually using FME, you can preserve the name/id of the feature is a related table as an output. This would give you the unique id and you'd be able to summarise.

Re: Quantifying overlapping polygons

JonM32 — Tue, 11 Aug 2026 11:46:56 GMT

@CristoforosRomanos

I'll take one more try at this...

This may not be the cleanest way to do it but it's automated and seems to work:

Buffer polygons
Spatial Join
- Target features: buffered polygons
- Join features: buffered polygons
- Join operation: one to one
- Match: Intersect
Symbolize output by the Join_Count field
- You'll need to subtract 1 from the Join_Count field to get the number of times a single polygon overlaps another polygon (field calculator would work well for this)

Re: Quantifying overlapping polygons

CristoforosRomanos — Wed, 12 Aug 2026 04:22:52 GMT

Hi Jon. You must be a magician. Your proposed method works. Perhaps not perfectly (especially at the highest end of overlaps where some visual sorting is required) but it is extremely helpful and certainly cuts down on the time I need to dedicate to this task. My sincerest thanks.

Enjoy your summer. Chris.

Re: Quantifying overlapping polygons

DuncanHornby — Wed, 12 Aug 2026 10:58:23 GMT

Have you explored the Polygon Neighbours tool, sounds like that tool could do what you want?

Re: Quantifying overlapping polygons

JonM32 — Wed, 12 Aug 2026 11:13:49 GMT

@CristoforosRomanos

I'm glad it was helpful! I knew there had to be a way to do this with a tool.

Have a good summer as well.