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tabulate area with overlapping buffers

July 06 2009 | 0 comments
Categories: ArcGIS Methods

What tool can I use for calculating the area of various features or raster values within zones defined by overlapping features?

For several different analyses I have found myself wanting to calculate the area of various features or raster values within feature zones (that overlap). I have tried several things including 'tabulate area', 'join by spatial location', and 'intersection', however, it seems whenever I have alot of overlapping zones the program does not work. Thank you.

Mapping Center Answer:

Since I'm more familiar with vector based methods for this sort of thing, I'll focus on a solution using polygons. At face value, I would start with the Union tool.  This will produce a fabric of boundaries that will contain intersected (as you likely hoped the intersection tool would do), and that preserve the attributes of the original polygons. two overlapped then two polygons representing the overlap will produced, each containing the attributes of the original overlapping polygon.  If three polygons overlapped the same area, then three polygons will be produced, covering that area, and so on.

(Note: if you want a fabric of non-overlapping polygons, you can use the Feature to Polygon tool, but that will not preserve the attributes of the original polygons).

Now you can use the Select by Location tool (or interactively) to conditionally select polygons from this fabric that have centroids within the larger polygons of interest.

You can also use the Feature to Point tool to create centroids for the polygons that result from the Union tool.  Then you can use the Collect Events tool to produce a non-overlapping point dataset where each point will have a count of the polygons that overlaps that point. That dataset may prove helpful in using the select by location tools.


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