I came across Generalizing polygon file while maintaining topology in QGIS? which asks for a QGIS solution to my exact question. I'm trying to do this in ArcMap. I start with a polygon shapefile (WGS84).

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I verified by importing it into a file geodatabase feature dataset topology that it does not have any gaps or overlaps. Then I run the Simplify Polygon ArcToolbox tool on it.

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The output has visible gaps and overlaps between some polygons. I added that layer to the topology and it shows me the rule-violating areas.

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I'm kinda an ArcGIS Topology noob though - one thing that has me confused is the Topology Toolbar remains entirely disabled. And even if that wasn't a problem I'm not keen to have to repair gaps and overlaps one by one interactively. Even if there aren't that many issues this time, there will be next time. Ideally I'd come up with a simplification with topology preservation workflow that is entirely automated. Is there a better way?

  • The topology toolbar won't be enabled until you start an edit session. Apr 9, 2016 at 0:41
  • ha! Noob indeed.
    – MC5
    Apr 9, 2016 at 0:41
  • Did you run the tool on the shapefile or the feature class? Apr 9, 2016 at 0:43
  • interesting. first the shapefile, and after your comment, the feature class. slightly different results in that visible gaps and overlaps occur in different locations, and when I add the output to the topology add add rules for it, no errors are found, at least with the default settings I applied when I created the topology. Odd. I'll have to monkey with this more on Monday. Thanks for the attention.
    – MC5
    Apr 9, 2016 at 0:53
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    The gp tools generally work better with feature classes. Another thing to try is to use a feature class that is projected rather than in a geographic coordinate sys (wgs84). Apr 9, 2016 at 1:05

2 Answers 2


Project polygons

Add geometry attributes, inside centroids coordinates and convert to points to store attributes

Convert polygons to polylines and simplify them.

Build polygons and transfer attributes using spatial join


To throw something else into the mix, you can buffer inwards, simplify the polygons, convert the vertices to points, run voronoi (thiessen) polygons on the points, then dissolve on the original IDs

QGIS appears to be way easier though

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