I have two polygon layers, a vegetation layer and a treatment layer. I want to add a field to the attribute layer of the vegetation layer to indicate if any part of the polygon has been treated (overlaps with a treatment layer).

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For the above example - I want an attribute table that ends up looking like

attribute table example

I do not want to intersect the two layers - I need to keep the full polygons in the vegetation layer, I just want to know if they've been treated. There are too many polygons to do this manually.

  • Using Intersect doesn't damage the input sources, so your objection to using it doesn't make sense.
    – Vince
    Commented Apr 16, 2019 at 11:18
  • I'm possibly misunderstanding how intersect works - but when I applied intersect to the two layers I got out a third layer that shows just the areas that overlap between the two - rather than what I am after, which is the polygons in Vegetation that have any intersection with any polygon in Treatment.
    – Esme_
    Commented Apr 16, 2019 at 22:21
  • Once you have the relationships, building the table is just a join or summary stats and a join away.
    – Vince
    Commented Apr 16, 2019 at 23:45

2 Answers 2


If you want to avoid using the Intersect tool, it seems you have two simple and quick options:

  1. Select by location from the vegetation layer features that intersect the treatment layer. Then, use field calculator to change the isTreated attribute (when you use Field Calculator and you have features selected, it will calculate only for selected features).
  2. Use spatial join with the vegetation layer as target layer and the treatment layer as join layer. Use a one-to-one relationship and choose to keep all target features. This will create a new polygon layer, with the exact same features as your original vegetation, and the features that intersected the treatment layer will have adopted attributes from the treatment layer. You can then use Field Calculator similarly, for the isTreated Field.

To do this I would use the Intersect (Analysis) tool which creates a new feature class that includes the feature IDs of both input feature classes.

You can then use a join to isolate any features in either of the input feature classes (which retain their full polygons) to update a flag field to indicate their overlap.

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