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
  • 1
    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

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.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.