[GRASS-user] Personalised raster alghoritm (simple: area)

[Moritz Lennert]

On 12/06/12 09:18, Antonello Lobianco wrote:
> Hello everybody on the list!
>
>    I am a "occasional" grass gis user and I'm stuck with a relatively
> simple task: I have a high-res vector layer describing only one category
> (Corine Land Cover map for "broad-leaved forests", 311) and I want to
> rasterise it in a low-res 8-by-8 km raster map where the value stored on
> each cell is the area (or, that's the same, the share of the area) that
> the vector cover within that cell.

Just for the record: you could also do the entire operation with vectors 
(using an SQL attribute backend, e.g. SQLite our PostgreSQL):

- v.mkgrid to make the grid you desire.
- v.overlay to overlay your grid with your CLC map
- calculate areas of resulting polygons
- through SQL, sum area of forst polygons grouping the result by grid id
- join the result to your original grid
- rasterize the grid

Moritz