[Qgis-user] Ho to intersect layers with some conditions

[Levy Vincent]

Hello,

I have a layer with a big polygon and another layer which is a grid (made of squares 10X10m). The grid is larger than the big polygon and cover it entirely.
I want to keep only the squares of the grid contained in the polygon. I know how to intersect my two layers  to select all the squares of the grid inside my "big polygon".
The problem is on the border : I would like to select only the squares which 90% of their surface is contained in the big polygon.
Is there any plug-in or another solution to do it easily?
I hope somebody could help me, thank you for your answer,

Vincent LEVY
Chargé de mission scientifique
Conservatoire botanique national de Bailleul
Antenne Picardie
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