I am using ArcMap 10.1. I had an orthophoto of an old study site. I traced two polygon shapefiles from this photo- one of "fields" and one of "forest". I made a point shapefile of the sampling points, and a polyline shapefile of all possible paths between the sample points. If a butterfly were to fly from one sample point to another (assuming linear flight along the polylines), I am looking to determine:

  • what percent of that flight distance was through field?
  • what percent of that flight distance was through forest?
  • how many times that individual had to cross a forest/field edge?

I haven't used GIS since my intro class many years ago, and I can't even figure out the correct vocabulary to search for the answer myself.


1 Answer 1


Here is one way to do it, it may get you started in the right direction:

  • add field to flight path shapefile named PathLength. Right click on new field and Calculate geometry
  • Merge your fields and forest shapefiles into one shapefile with a Type field designating each type
  • intersect flight path with new forest/fields shapefile
  • on the output line shapefile from the intersect task, add a new Segment length field and calculate length
  • Add new field to output line shapefile named percentage, calculate using field calculator as (seg length/PathLength)*100

The intersect job will have attached all of the attributes from the forest field shapefile, so each segment will now have whether it is in a forest or field and the percentage of the total length

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