Question

Overlapping polygons within one dataset

  • 18 June 2021
  • 2 replies
  • 249 views

Badge +4

Hi. I have a polygon dataset showing planning applications. I want to find out if any of the polygons intersect others in the same feature class. I have tried feeing the data into the are on area overlayer twice and it has come up with some results however, it says in the instructions there should be no self intersections within the layer, so I think I need a different transformer

 

Has anyone got any suggestions please?


2 replies

Userlevel 6
Badge +33

I think the AreaOnAreaOverayer should work just fine in your situation?

Userlevel 1
Badge +21

If you want to find overlaps, and don't want to chop up all the data I would use the Spatial Relator, send it to both Requestor and Supplier and set the Attributes must differ parameter to a unique identifier for each polygon.

 

You can then test for related_candidates > 0. If you set a list parameter in the SpatialRelator it will tell you which polygons overlap with each feature.

 

One thing to be aware of is there is no tolerance within the Spatial Relator so it may report lots of very minor overlaps that you are not interested in.

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