dmede

Intersect, Union... or? (now: how to combine stacked polygons)

Discussion created by dmede on Feb 15, 2011
Latest reply on Sep 14, 2016 by jsencinas
I have a geo-processing question I need some help with.

I have a student (I'm a GIS assistant/intern at local library) who has a single feature class with multiple overlapping polygons representing distributions by species (so each poly has only one attribute, a single species type). The student would like to output a new layer where each polygon overlap becomes a single individual polygon with attributes reflecting all of the species present in the overlap area. The image below may help conceptualize this (mostly for me!).

What I need are the overlap areas as single new polygons showing the species present from the input polygons (so one new poly each for AC, ABC and BC). Not stacked polygons where the area for say ABC would actually end up as several new polys (AB, BC, AC). From the documentation I can't tell if Union will do this in a single step or if I need to run another process after that to merge the resulting output stacks... or if I need another tool all together?

Any help is appreciated,
Dave

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