I am using QGIS 2.18.9 and I have a problem. I dissolved a small map with about 1000 small regions into one big polygon, with Vector->geoprocessing tools->dissolve.

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But after the dissolving there are little dots everywhere. After zooming in I found that these are all little holes in the layer. enter image description here

Now I want the dissolved layer to not have any holes. Is there an easy way to do that?

  • Please note that this is not a QGIS problem, but a data problem. Your data is not topologically correct, and that is why you get those small holes. Jun 8 '17 at 9:12

You can use a positive buffer + negative buffer in a row (extend/shrink method) for example.

Here, we have a polygon with a hole (hatched polygon). I buffer it by plus a distance (makes the polygone with the dash line) then by minus a distance (polygone with the black line). At this end, the hole disappear, eaten in the buffer + operation. The downside might be that if your buffer is too big, you might have a smoothing effect on your original entities.


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