[GRASS-user] Reverse flow accumulation

[Jonathan Greenberg]

Typically flow accumulation tracks the number of pixels that are uphill of a
given pixel, but is there anyway to track the number of pixels that are
DOWNHILL of a given pixel (e.g. to the drainage outlet)?  The reason I ask
is that I'm dealing with a riparian bathymetry dataset which does not
encompass the entire watershed although it does include the outlet as well
as an unbroken, continuous distribution of values upstream from that point
until it terminates at an arbitrary boundary, but I want to have a proxy of
the flow to those points.  Uphill accumulation will not work because the
"origin" of the streams is completely arbitrary (e.g. I can't just assign
them a value of "0" at the edges).

Thoughts?

--j

--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N 
Davis, CA 95616
Cell: 415-794-5043
AIM: jgrn307
MSN: jgrn307 at hotmail.com