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I'm trying to split polygons into equal areas. While fishnet sort of works; the areas I'm trying to split don't touch; they're national parks. Fishnet spans the whole area, not just the polygons in question. Ultimately, I'm searching for a method to split polygons into a user-given number of equal area polygons.

I've read everything I can about the Huber methods to do this in ArcView, but without access to that (or experience with it) this isn't the answer for me.

Thanks very much.

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  • Have you considered this similar question: gis.stackexchange.com/questions/5300/…
    – dassouki
    Commented Jan 24, 2011 at 20:52
  • Are the national parks polygons or multipolygons? How would you like those to be handled?
    – underdark
    Commented Jan 24, 2011 at 21:45
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    I have tried to describe the algorithm in a non-AV centric way (in the link provided by @dassouki). It will work in any GIS that supports scripting where you can (a) implement a 1D root finding algorithm, (b) clip polygons to rectangles, and (c) compute the area of a polygon. (A variant replaces (b) by (b') internally buffer polygons by specified amounts. This will dissect polygons into pseudo-concentric rings of specified area.)
    – whuber
    Commented Jan 25, 2011 at 14:37
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    @MBarretts Read sections 9.0 - 9.3 of Numerical Recipes; this will teach you all you need to know about root finding. nr.com/bookreader_chooser.html . I am curious about how "fishnet works," because as far as I can tell that just coarsely grids your polygons: something has to happen afterwards to effect the splitting.
    – whuber
    Commented Feb 2, 2011 at 16:51
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    @mbarretts, you say what software you don't have, Arcview, but you don't say what you do have. Also do you mean each split poly has to have the identical area , as in numerically identical # of sq km's for each feature? Because fishnet will not do that, some fishnet squares will be entirely within the parent poly, and others will only partially overlap.
    – matt wilkie
    Commented Feb 16, 2011 at 7:44

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