r.watershed and spearfish

[Mike Bender]

> I am a GRASS novice, but I need to prepare a demonstration of GRASS capabilit
i
>es.  Because our lab is looking to investigate integration of GIS with other t
oo
>ls for water resource management, I wanted to run r.watershed.  I am having di
ff
>iculty using it with the spearfish sample database.  I thought it would be ver
y 
>straightforward to specify the elevation.dem layer and produce subbasins.  Unf
or
>tunately, the output map is complete garbage.  I have tried a number of thresh
ol
>d values from 1 to 100, and I have gone through the interactive mode.  Nothing
 s
>eems to look right when it finishes running.  Can someone help?
> 
> 


I continued wrestling with r.watershed, and found out that my problem was runni
ng w
atershed without the -m flag.  On my Sun Sparc workstation, it seems that I can
't l
et my operating system control the use of virtual memory, even when the geograp
hic 
area is reduced to a very small region.  All I get is garbage output.

Mike Bender
University of Manitoba