Heat map from Buffered Layers

JoshuaMatthews

Hello!  I am working on project right now where I have 11 layers (all layers are buffers) and I want to create a heat map based on how many layers (buffers) overlap.  I am trying to follow these directions: http://forums.arcgis.com/threads/9740-Sum-of-Overlapping-Areas-Cells?p=33982&viewfull=1#post33982 because it seems to be exactly what I need to do, but I am not understanding the first part (union).  I am trying to follow that direction by selecting all of my layers as the union input, but the union is not finishing (I have left it going for hours, I think this is because my data is so large).  I was wondering if anyone knows a better way or a work-around that would get me what I am looking for.  I am relatively new to ArcGIS (2 semesters) and I am using 10.1.  I would really appreciate any help, thanks!!

DaleHoneycutt

Take a look at this blog article
More adventures in overlay: counting overlapping polygons with spaghetti and meatballs. 

The first thing you'll need to do is to combine your 11 layers into one feature class.  Use the Merge tool for this.  Then you can follow the pattern outlined in the blog post:

• Create (spaghetti) polygons from the merged buffers above using the Feature to Polygon tool
• Create (meatball) centroid points using the Feature to Point tool
• Use Spatial Join to count the number of overlapping polygons