Merge smaller polygons that are within a larger polygon

[MalcolmLittle]

Hello,

I am trying to find the best way to merge small polygons into one polygon. They have to be merged to match provincial subdivisions. What I'm working on you can see below:

So I have to merge the little aquamarine polygons into one for each subdivision, delineated by the grey lines. There are roughly 3260 aquamarine polygons, and 153 subdivision polygons. In the end I would need 153 (or less since some subdivisions do not contain aquamarine polygons) aquamarine polygons.

Any thoughts on how?

[SepheFox · Accepted solution]

Hi Malcolm, I would do a spatial join, using your aquamarine polygons as the target, and the subdivisions as the join features. That will put the subdivision info into each polygon in your other layer. Then I would dissolve your little polygons, using subdivision ID, or name or whatever unique ID they have, as the dissolve field.