I work in a library providing geospatial services and I have a patron with about 60 surveys with perceived accent regions in Mexico. Individuals drew on maps where they think people speak with different accents in Mexico. The end goal here is to have a map that combines the results of these surveys into one map.

Here is what one of the surveys looks like- enter image description here

He's got them georeferenced and then digitized to individual feature classes in a geodatabase. Now we've got polygons overlapping one another in different layers like so (I'm only showing 2 for simplicity). Each polygon in the layer represents a different accent region

First feature class- first feature class

Second feature class- second feature class

Both classes layered on top of one another layered on top of one another

How can I combine these 60 feature classes to make a map showing these perceived regions? The end result as something like a heat map would be perfect. Would that work very well with nominal data? I've poked around online and haven't found much help. I'm just struggling getting my head around visualizing the combination of all those layers.

I'm using ArcGIS 10.1 Build 3035.

  • 1
    How many accents total?
    – FelixIP
    May 12 '15 at 20:19
  • You might want to play around with this answer about creating a heatmap by overlapping polygon area.
    – dmahr
    May 12 '15 at 20:28
  • Do you have Spatial Analyst? I'm thinking a raster solution would be easiest. It somewhat depends on how you want to address conflicts between surveys - greatest number of responses for a particular accent in a given area rules? Show everywhere a given accent is perceived? I don't think you can do a heatmap concept with every accent in the same layer/map. You could do that per accent, but on a single map you're heading down the bi/tri/x-variate map and there's probably way too many accents to make that feasible.
    – Chris W
    May 13 '15 at 5:51

you could merge all layer into a single one then use "count overlapping polygon".

Another solution (among others) without external plugin is:

  • create an "union" of all layers (union tool, FID only)
  • create a new field an compute the number of FID > -1 (see below, boring to write in field calculator, sorry. You could use da.updatecursor if you prefer)
  • add a graduated color symbology on the new field
def countFID(a1,a2,a3....,a60):
    listFID = [a1,a2,a3   a60]
    return sum(x>0 for x in listFID)

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