[GIS] Summing attribute values for areas where multiple polgons overlap using ArcGIS Desktop

Question

I have one shapefile with many polygons (at least 100). Each polygon has a value. Almost all these polygons overlap with each other. I want to sum the values of the polygons in the overlappings depend on which polygons overlap in that overlapping area. The picture (simplified sketch) hopefully explains this.

But I can't find a method to achieve this in ArcMap (I use Arcmap 10.2.2). I have tried many times the Union tool and others like Merge, but I can't find a solution.

Answer 1

You can do this with 2 tools, Feature to Polygon and Spatial Join

First, run your polygons through Feature to Polygon. Delete any of the attributes you don't need from the output (I still got them even when I turned preserve attributes off):

Then, run Spatial Join:

• The target features are the output of Feature to Polygon
• The join features are your original layer.
• Edit the field mapping to contain just the fields you need, and set the merge rule on your count field to 'sum'.
• Set the Match Option to COMPLETELY_WITHIN (this is important!)

You should end up with your intersected boundaries with summed totals: