I am working in QGIS, doing research in different types of forest reserves. I've got this layer of reserves which are for some reason divided into a lot of small polygons (image below).

I want to merge polygons in 6 islands, by selecting polygons in each island that are touching each other. So as you can see in image below the result should be only 6 polygons, instead of these islands consisting from many polygons.

Is there any simple solution to this? I know how to do this manually by selecting and merging them but there are around 4000 polygons, so...

enter image description here

  • 3
    What GIS software are you using? Research Dissolve
    – Bera
    Commented Aug 18, 2023 at 9:12
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    – Ian Turton
    Commented Aug 18, 2023 at 9:24
  • I'd like to ask a question here in the comments. Maybe @Vince or someone else here could help me understand something, please? Is it against the rules to ask such rookie-level questions? Since it's not the first time I've seen them downvoted.
    – user99006
    Commented Aug 20, 2023 at 3:54
  • @user99006 Questions like this belong in Geographic Information Systems Meta. It's not "against the rules" to ask basic Questiions, though it might strike some as not being sufficiently researched.
    – Vince
    Commented Aug 20, 2023 at 13:35
  • Thanks for your answer, @Vince. I'll go check the GIS Meta.
    – user99006
    Commented Aug 21, 2023 at 1:05

1 Answer 1


You can do a Dissolve.

Make sure you dissolve without selecting any of the fields. After the dissolve you have to do a Multipart to Singleparts to divide the parks

  • It would be better to dissolve by ReserveCode, so that all attributes are not lost, and Multipart To Singlepart isn't going to work with the reserve to the northeast.
    – Vince
    Commented Aug 20, 2023 at 13:29
  • 1
    Yes, as @Vince said the attributes are lost, thank you nonetheless. how do you use ReserveCode?
    – BlaZF
    Commented Aug 20, 2023 at 15:08

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