[Qgis-user] polygon raster overlap

[Declan Troy]

Hi all,

I'd like to be able to overlay a series of polygons over a land cover  
raster to ascertain the composition (area or proportion) of the  
raster classes within the polygons. I think this should be a rather  
straightforward procedure.

So far I don't see a way of doing this directly in Qgis (maybe an   
"ftools" for rasters will appear). Have I overlooked something?

I presume this can be done in GRASS (not sure of the procedure yet).  
Would the easiest approach be to do this via grass tools in Qgis or  
directly in GRASS? Would it be necessary to  ship all layers to GRASS  
or does Grass Tools allow analysis of Qgis layers on Grass layers?

Thanks for any advice or direction.

Declan