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I am looking for a process in QGIS to run a selection from a given point based of a radius that ignores "islands". For example you may have a body of water which acts as a natural barrier past which I do not want to select any features.

Please see my image as an example:

enter image description here

As you can see in this example the selection was made from a point on mainland England but polygons on the Isle of Wight has been selected even though they are separated by the Solent.

enter image description here

It may also be the case that the multi polygon itself does not contain an island but the selection creates one (see above).

I am not necessarily looking for a single tool or plugin because I don't think it exists, but is there anything I can incorporate into the graphical modeler to get around this? I'm thinking of a rule that ignores any polygons that do not touch.

  • You could put islands on a separate layer from the mainland data. – Erik Mar 22 at 9:16
  • @erik thanks for your comment - my example might not be a good one because by island I mean an island created by the selection and not the island itself. For example islands can be created on data sets that loop around on them self. – AWGIS Mar 22 at 11:40
  • @erik I have edited the question which should hopefully make it clearer. – AWGIS Mar 22 at 11:46
  • So you want all selected features to be connected to each other? – Erik Mar 22 at 11:46
  • 1
    Sounds like a topology-based selection approach might help. – Trevor J. Smith Mar 22 at 14:22

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