[GRASS-user] Flat area issue in r.watershed

[Markus Neteler]

On Thu, Mar 25, 2010 at 2:45 PM, Margherita Di Leo <diregola at gmail.com> wrote:
> Hi List!
>
> I often use the tool r.watershed and I always wonder that it seems to be not
> affected by the issue of flat areas . How it manages the surface flows in
> low/zero slope areas?

AFAIK it uses a least-cost algorithm (A^T search) to figure out the *best* way.
The man page contains a reference to Chuck Ehlschlaeger's document about
this method. Ah, I see that the link is now
 http://chuck.ehlschlaeger.info/older/IGIS/paper.html
will update the manual page.

Markus