I have a 23M DEM that I ran r.watershed on to try and
calculate the flow accumulation (area weighted):
r.watershed -m el=elv ac=flowacc
The process crashed after consuming all of the 1.7G of
free space on my partition (in the .tmp directory of
the mapset)!! Everything worked just fine on a small
elevation grid I had downloaded for a tutorial. I had
masked out the NULL areas (I think). Any clues as to
what is going on? Is there an equivalent command to
arc/info's flowaccumulation that is more space
efficient? How about the A^t search algorithm? I'm
not much of a number cruncher and haven't heard about this.
=====
--
David Finlayson
david_finlayson@yahoo.com
University of Washington
Box 351310
Seattle, WA 98195 - 1310
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On Mon, Sep 25, 2000 at 07:39:38AM -0700, David Finlayson wrote:
I have a 23M DEM that I ran r.watershed on to try and
calculate the flow accumulation (area weighted):
r.watershed -m el=elv ac=flowacc
The process crashed after consuming all of the 1.7G of
free space on my partition (in the .tmp directory of
the mapset)!! Everything worked just fine on a small
elevation grid I had downloaded for a tutorial. I had
masked out the NULL areas (I think). Any clues as to
what is going on? Is there an equivalent command to
arc/info's flowaccumulation that is more space
efficient? How about the A^t search algorithm? I'm
not much of a number cruncher and haven't heard about this.
Hi David,
to calculate flow accumulation, try:
r.flow and
r.flowmd (multiple flow)
http://www.geog.uni-hannover.de/grass/gdp/html_grass5/html/r.flow.html
http://www.geog.uni-hannover.de/grass/gdp/html_grass5/html/r.flowmd.html
It is coming along with GRASS 5.
Hope this help
Markus Neteler