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How can I split the green area as a separate polygon fro the grey one in QGIS?

marked as duplicate by PolyGeo, Fezter, Devdatta Tengshe, Simbamangu, Mapperz Jan 20 '14 at 14:59

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  • Do you mean that you want to use the green polygon to punch a hole in the grey one to leave a doughnut polygon? If so, look for tools with names like erase or a clip that has an option to discard (rather than keep) the area of overlap. – PolyGeo Jan 19 '14 at 21:27

you can use the union tool (vector > geopprocessing tool > union). It will create two polygons with the union of the geometry from the two inputs.

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