r.mapcalc

[Frank Lederer]

Hi GRASS-users,

unfortunately I could not solve my problem now: I would like to calculate
the area, that can be flooded by a river. I want to use a DEM and a
streamchannel map. The algorithem (r.mapcalc) should look on each
streamchannel-rastercell and then calculate all surrounding rastercells (of
the DEM) that are 2 meters higher. 
Any suggestions?

Thanks
        Frank