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I've put a 20m buffer on all of my points (144,000 observations), dissolving all overlapping buffers.

How do I then take the centroid of the dissolved buffers in QGIS?

I want to reduce all overlapping areas to one point.

  • Is 'Vector > Geometry Tools > Polygon Centroids' not what you're after? – Knightshound Oct 25 '16 at 14:52
  • That gave me a single centroid for all the points, rather than a centroid for each individual buffer zone – Thirst for Knowledge Oct 25 '16 at 14:55
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    Sound like the buffer is a multipart polygon if you're only getting a single centroid. Try using Multi-part to Singles parts, then run centroid. – Knightshound Oct 25 '16 at 14:57
  • Bingo. Thanks, that's great. Want to put it as an answer and I'll mark it as correct? – Thirst for Knowledge Oct 25 '16 at 15:07
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Dissolving your buffer creates a multi-part polygon. Using the tool 'Polygon Centroids' will only create the centroid for that multi-polygon. What you should do first is convert the multi-part using 'Vector > Geometry Tools > Multipart to Singleparts'. Then run the centroid tool to create centroids for each individual buffer polygon.

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