I am working in QGIS 3 and I have a shape file containing many polygons. Several of the polygons have very thin gaps created by the bounding line of the polygon and they do not penetrate the entire width of the polygons – see the attached picture: 
I have tried several methods to remove these with no success. I have tried the v.clean, remove holes, simplify and generalize functions and none of these were successful
Is there a technique that can be used to remove these gaps?
Best Answer
Apply a buffer with a size that it covers the hole. Than apply another buffer with the same, but negative value.