I successfully cut out of the source DEM a small area matching that of the
project watershed. When I ran r.slope.aspect the output maps looked as they
should.
Feeling irrationally exuberant that I might be able to quickly move on to
hydrological modeling, I just tried running r.shaded.relief on the same
raster DEM map used for the slopes, aspects, and curvatures. No joy. the
relief map looks like the earlier slope and aspect ones: vertical bands of
horizontal static.
This is all within the latest weekly checkout of 6.4. What might I be
missing if all I specify to r.shaded.relief is the input and output map name
and leave the other options at their defaults?
Rich
On Tue, 26 Jan 2010, Rich Shepard wrote:
Feeling irrationally exuberant that I might be able to quickly move on to
hydrological modeling, I just tried running r.shaded.relief on the same
raster DEM map used for the slopes, aspects, and curvatures. No joy. the
relief map looks like the earlier slope and aspect ones: vertical bands of
horizontal static.
Got this fixed: it was incorrect region resolution.
Now I have a question about the results. The source DEM has the highest
area in the southeast corner and the main stream drains northwest to the
confluence with a large river. The shaded relief map, however, does not
reflect this topography. Both maps have a resolution of 10m.
On the shaded relief map, the drainage basin head appears as flat as the
confluence area.
Why might I see results like this? Do I need to interpolate the source DEM
to a finer resolution before running r.shade.relief?
Suggestions needed,
Rich
On Wed, 27 Jan 2010, Rich Shepard wrote:
On the shaded relief map, the drainage basin head appears as flat as the
confluence area.
Fixed this, too. r.shaded.relief needed the zmult set higher than 1. '5'
does very nicely.
Rich