Green:current polygons, red line: I want to split them on those areas

I came up with a polygon shapefile like what you see here. There are some small polygons which exactly match what I want, though I want to cut(split) those bigger ones into smaller pieces.

So far I have tried many combination of different commands. I converted this to polyline and again to polygon, and from these 2 shapefiles, I ran cut with polyline, multipart to single part, extend the line, minimum boundary around it polyline and convert to polygon again or merge, intersect, dissolve, eliminate, ...etc. (I didn't write them in order)

I am afraid what I want is not possible at all. But anyone got any idea how to do this?

Even roughly on some larger polygons. P.S: I have full Arc GIS licence.

  • Would you be able to edit your question to specify whether or not you have access to the Spatial Analyst extension, please? If you do then a nibble/expand technique as mentioned at gis.stackexchange.com/a/14820/115 may be worth investigating.
    – PolyGeo
    Oct 29, 2014 at 6:54

1 Answer 1


My money would be on Polygeo's suggestion in the comments prior to rasterizing. However, working with your polygons, you could select the smaller polygons and save them to a separate file (you'll see why shortly). Then de-buffer (negative buffer value) your polygons. Then split multiparts to single parts (important). Next buffer the result of that operation by the same amount as you de-buffered. This will give you a close approximation to your original polygons but split at the 'pinch' points. Recombine this with your small polygons.

You take out the smallest polygons so as not to loose them altogether, though you could do a spatial query to find which polygons got lost altogether... which might be a better way of doing it as you can play with the de-buffer amount without having to second guess which polygons to remove.

Bear in mind that the result of this operation will not be exactly the same as your input but it looks like it comes from a raster->vector operation so the boundaries are probably not that exact anyway.

  • Thanks for your comments guys. I tried different things but what MappaGnosis said is closer to what I am looking for. cheers.
    – G.Z
    Oct 30, 2014 at 15:58

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