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I've searched previous posts to see if anyone asks a similar question, but I haven't found anything. I have a multiple feature classes, each containing multiple polygons. I have two desired outcomes:

A) I would like to find any easy way to create a new single feature class in areas where more than 50% of my input layers intersect. The number of input layers I have will vary, but let's use 6 as an example. It would be nice to be able to create a single feature class no matter which of my four input layers make up the more than 50%. I've tried to create a model using Intersect, but I am missing the logic piece that tells the system that not all 6 inputs need to overlap, just at least four.

B) The other output I would like to have is a new feature class which creates new polygons which are an average area based off my inputs. In this case too I would like this tool to create a new feature class with the mathematical average of areas where more than 50% of my inputs overlap. I've searched, but cannot find any such tool that can get me at my output.

I currently have an ArcInfo (Advanced) license, but no extensions. If there is a way to accomplish my goals with either ArcView (Basic desktop) or ArcInfo that would be preferred. But if there is an extension out there I would be curious to know what it is.

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    Please update the question to specify the storage format of the data. – Vince Mar 24 '15 at 17:41
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Answer based on 3 polygon layers:

enter image description here

  1. Merge (Geoprocessing-Merge) all layers into single dataset, ALL_PGONS
  2. Intersect ALL_PGONS (Geoprocessing-Intersect). No SECOND layer, output INTERSECT
  3. Create new text field in the table of INTERSECT, call it LINKFLD
  4. Populate this field using field calculator (Python) using something like this (I assume you are working with projected system):

    '%i %i' %(int(!Shape!.centroid.X),int(!Shape!.centroid.Y))

  5. Create new short field in the table of INTERSECT, call it ONE

  6. Use Summary Statistics to count number of unique values stored in field LINKFLD: enter image description here

Join output table (freq.dbf in above example) to INTERSECT table using LINKFLD. You can symbolise intersect using FREQUENCY.

enter image description here

You can also select polygons frequency of which is above 50% of layers count. Their extent is your answer.

  • @JR OMA built on this to get answer to your B question – FelixIP Mar 25 '15 at 2:00
  • Thank you for your help. Unfortunately, I am getting stuck on step 4 of your instructions. I an not very familiar with Python and I cannot seem to figure out how to enter the script you provided in it's entirely to get the process to run. I am using projected features in Nebraska State Plane. Thank you – JR OMA Apr 17 '15 at 17:14
  • This not a script. This is FIELD CALCULATOR expresiion. Open table, select field LINKFLD, right click etc. Search help for field calculator... – FelixIP Apr 17 '15 at 21:49

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