[GRASSLIST:5469] Re: r.watershed

[H. Bowman]

> I am having terrible problems with r.watersheds.  In short: I can't
> get it to work!  I am trying to estimate the confluence of present-day
> basins if the sea level was lower.


Try loading the DEM into NVIZ, Panel-> Surfaces, New: Constant, 0.0
Transpenency: new constant 128
Color: new constant [blue] 

then 'draw current'.

You should have a semi-transparent blue surface at 0 elevation representing sea level.

Raise and lower sea level with the 'Position' button (eg z=-30) until the basins separate.

It isn't exactly scientific, but it works pretty well and looks good too.


see http://bambi.otago.ac.nz/hamish/pics/sill_iceage_115m.jpg for an example.


Hamish