4

I have a point shapefile in QGIS 3.26. It is made of many points, and many overlap with each other. I need to make a polygon shapefile out of these points so that those points that overlap or are close to each other get merged into one polygon. I also need the border area of these points in a polygon format.

Is there a way to do this in QGIS?

enter image description here

The buffer tool window:
enter image description here

Improve this question
3
  • 5
    DB-Scan cluster first, then create convex hulls based on the cluster Ids.
    – Erik
    Commented Nov 8 at 11:24
  • 1
    Consider posting this as an answer
    – GeoMonkey
    Commented Nov 8 at 11:31
  • Thanks @Erik. Could you please explain a bit how I can do this step?
    – Paris
    Commented Nov 8 at 11:38

1 Answer 1

Reset to default
7
  1. Buffer the points with a positive distance, I use 50 m. Set Dissolve result=Yes and Keep disjoint results separate=Yes
  2. Buffer the buffer layer from step 1 with the same but negative distance -50, to create the green polygon layer:

enter image description here

Improve this answer
4
  • Thanks. I add a screenshot of the buffer window of my question. It does not have the 'Keep disjoint results separate' option and for 'Dissolve result', I selected it.
    – Paris
    Commented Nov 8 at 12:14
  • I guess you have another QGIS version, I have the option here. If you end up with one large multipart polygon, split it with Multipart to singleparts
    – Bera
    Commented Nov 8 at 12:19
  • Why do I have to create two buffers? one with a negative distance value? I set my distance as 1m and it is already big. Considering areas outside the points that it should not.
    – Paris
    Commented Nov 8 at 12:43
  • 3
    Thats why you buffer the first buffer output with a negative distance, to remove the parts outside the points. You should not buffer the points twice
    – Bera
    Commented Nov 8 at 14:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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