[GRASS-user] stream network extraction via detection of curvatures in a DEM

GRASS GRASS user
1

I found these message which discussed about David Tarboton's algorithms.
http://grass.itc.it/pipermail/grassuser/2006-May/034150.html
Dylan said there was an overview of stream network extraction via detection of curvatures in a DEM.
Is it able to do this via the GRASS? how to do the same in GRASS?

Thanks!
Li