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Is there a simple method to select singlepart non-overlapping polygons in a single feature-class which are not contiguous with other polygons ie they are island polygons?

  • Please edit the question to contain details on whether your "island" geometries are single-part or multi-part (it significantly alters the question). – Vince Jun 29 '15 at 15:29
  • @PolyGeo perhaps this question could be merged with its duplicate so that we collect the answers in a single place? – Chris W Jul 12 '15 at 20:48
  • @Chrisw I don't think these two Q&As should be classed as exact duplicates (so not merged) because the case here, where the polygons may touch but do not overlap, has simpler solutions. Making them duplicates would mean (I think) that the answer from FelixIP would not apply to the overlapping case. I'm going to edit their titles to reflect that. – PolyGeo Jul 12 '15 at 22:29
  • @PolyGeo The overlap discussion at that other question relates to the method of selecting the polygons with buffers, not the polygons themselves or that identical polygons may be stacked. I agree the wording is unclear (which is why I'd requested an image), but it's the other, non-isolated polygons which may share borders or overlap. I believe both questions seek to identify the same types of polygons - singles that do not in any way touch another. Felix's solution would work there, with an added benefit of at least visually flagging those that appear isolated but aren't. – Chris W Jul 16 '15 at 21:50
  • @ChrisW You may be right. I've not tested before making my comment above. However, before considering a merge of this Q&A with gis.stackexchange.com/questions/94979/… I think we should endeavour to bring all the answers to the standard of FelixIP's and to extend that one to show what happens when an overlapping polygon is introduced to the input. – PolyGeo Jul 16 '15 at 22:10
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This is untested but to do this I would try these steps:

  1. Polygon Neighbors to create a table of polygon neighbors - islands should have no records in this table
  2. Use a join between the feature IDs in the feature class and the neighbors table to select any that match - these are not islands
  3. Switch selections in the feature class
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Spatial join to itself:

enter image description here

ORIGINAL POLYGONS:

enter image description here

JOINED POLYGONS:

enter image description here

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