I have two categorical datasets (polygons) and I am trying to find out how many of the categories fall within a buffer for each (one has 8 categories, the other 33).

I have used 'tabulate intersection' to get the percent of each buffer covered by each category so could manually go through and work out how many categories are in each one but as I have more than 600 points I would rather try to avoid this!

  • 3
    How about a Union/Intersection/spatial join (depending on what you want to do with the non-intersecting area) between the buffers and the category feature classes followed by Summary Statistics with case fields of Buffer ID (or any other field that is unique in the buffers) and statistics field of category with a type of COUNT. – Michael Stimson Sep 11 '17 at 4:00
  • This did what I wanted, however because there are many polygons within the buffer for the same category, it counted each one as a separate value - so for an example buffer rather than give me a value out of 8 (the 8 category dataset) I got a value of 167. – Libby Timmiss Sep 11 '17 at 4:22
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    Then you will need to dissolve resources.arcgis.com/en/help/main/10.2/index.html#//… by buffer ID and category to make multipart features before executing the summary statistics. – Michael Stimson Sep 11 '17 at 4:44
  • That's good news, now can you please answer your own question with diagrams and perhaps an example of the output. – Michael Stimson Sep 12 '17 at 0:47

I used tools 'Intersect' then 'Dissolve' then 'Summary Statistics' to answer this question.

First I had to intersect the the categorical feature classes with the buffer polygons enter image description here

I then had to 'dissolve' this output by both the bufferID (in this case "CampID") and the categorical information (in this case "GRIDCODE"), ensuring multipart features was checked (yes). enter image description here

Then, I completed summary statistics on this new layer, with case fields = Buffer ID ("CampID") and statistics field = category ("GRIDCODE") with a type of COUNT. enter image description here

an example of what my intersected+dissolved output looked like: enter image description here

an example of the data output - where "CampID' is the buffer ID, and "COUNT_GRIDCODE" is the number of catgories that occurred within that buffer. enter image description here

  • Nice answer, easy to follow with lots of diagrams. +1 from me. – Michael Stimson Sep 12 '17 at 5:17

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