[GRASSLIST:10676] Re: Stream network in GRASS?

[Hamish]

> Check out r.terraflow --> reclass the topographic index output map.
> See example here:
> http://casoilresource.lawr.ucdavis.edu/drupal/node/166
> 
> Also try:
> r.flow
> r.topmodel


One idea I've been playing around with-

Treat accum output map as a DEM, then use 'r.param.scale param=feature'
to classify the ridges. Then r.mapcalc to turn the ridge areas into a
MASK, r.thin, etc.


Really what I've been trying to do is calculate width of a river. So far
I've been able to use the polygon to a distance_to_shore map using
r.cost which gives me something of similar shape to a river flow map,
then above proceedure & double the center line value and grow that out
to the shore using r.grow & a cellular automata loop. This should end up
with a raster layer showing the width. I'm trying to avoid arbitrarily
drawing a line down the axis of the polygon & doing the right-angle line
crossing polygon calculations..



Hamish