How to eliminate polygon overlap areas in QGIS?

Question

Is there a way to remove polygon overlaps within the same layer using QGIS, preferably removing the overlap area of the biggest polygon (having the greatest surface)?

All of my polygons are in the same layer, and I would like to perform this operation on the entire layer at once rather than manual editing.

Answer 1

You can use Eliminate sliver polygons tool to eliminate the small polygons, as you can see below:

You have two options to eliminate polygons:

1. Area: eliminate polygons based on area in which the smaller polygon will be eliminated if they area located inside big polygons
2. Common boundary: if there is a common boundary between two polygons, they will be eliminated.

In your case, since you need the smaller polygons to be eliminated, I think option 1 is the best one for you.

You can find Eliminate sliver polygons tool from Vector -> Geoprocessing tools -> Eliminate sliver polygons

Answer 2

You can not choose which polygon gets the overlap part by size, but apart from that, this should do what you are looking for: https://gis.stackexchange.com/a/381790/107424

Answer 3

You can do that with Vector -> Geoprocessing Tools -> Difference of the Menu Mar.

Two arbitrary shapefiles overlapped near of Europe area:

Difference Tool Window where the input vector layer is big_polygon and the difference layer is small_polygon.

The resulting difference polygon: