I have thirteen polygon layers showing species at risk ranges – I have a standard arc GIS desktop license, allowing only two inputs to the intersect/union tool at one time. I need to create a "hot spots" layer showing where the ranges overlap. I need more than a polygon where all 13 layers intersect though, I need all types of overlap, ex. showing where two ranges overlap and three layers overlap etc. I feel like there is probably some way to do this via multiple intersect/union but I can't wrap my head around it. Alternatively I could merge all layers into one polygon files, and intersect it by itself – but then I can't figure out how to combine overlapping polygons into one with all attributes intact.
[GIS] Intersect Multiple Layers
arcgis-desktopbasic-license-leveloverlayvector
Best Answer
Here is one approach that I think would work for you.
1.) Add a unique field to each of the input polygon layers.
2.) Populate each field with an identifier you can easily associate to that species.
3.) Iteratively run the Union tool for each layer union-ing to a master polygon layer. Now all of these unique fields will be included in your output polygon data set.
4.) Create a new text field in your output feature class.
5.) Use the python parser in field calculator to create a list of the species present in the polygon.
Something like: