[GRASS-user] Re: grass-user Digest, Vol 30, Issue 61

[Richard Chirgwin]

>
> Hello Users group
>
> Have two vector-maps with areas map-A and map-B
>
> Is there a grass-module to calculate the total surface (m2 or ha by 
> category)
> of the areas of the map-B witch are inside the area(s) of the map-A.
>
> Thanks
>
> Joop Goedbloed
>   
Joop,

Combine the two maps using v.overlay:
v.overlay ainput=<map-A> binput=<map-B> output=<output_name> operator=and

The geometry of the output map will have the area of map-B falling
within map-A. If you need, you can then upload the area to the database:
v.db.addcol map-B columns='area double'
v.to.db map=map-B option=area units=<m or h depending on metres2 or
hectares> column=area

Richard Chirgwin