On 15/04/14 13:03, Thomas Adams wrote:
Moritz et al,
Thank you for the helpful suggestions. One of the problems I have is
that about half of the points are in a tidal estuary where the
elevations are all zero (sea level); so utilizing the elevations to sort
will not work -- I have several thousand points I'm dealing with, which
I obtained by doing a vect-->rast conversion and then got the points
from the rast (I know this sounds screwy).
I have to explain what I'm doing. I want to use r.inund.fluv to generate
a flood inundation map. The problem stems from the fact that I have a
USACE HEC-RAS model implementation which was not georeferenced, from
which I have modeled water surface elevations from a historic flood.
From an ascii output file, I basically have the channel centerline
locations (x,y) and water surface elevations and I have calculated the
distance to the river mouth at each point. In GRASS I have
independently, using a UTM map projection, the channel centerline as a
vector. I have also identified the corresponding upstream and downstream
end points, which identify the same locations -- so I plan I 'mapping'
the HEC-RAS water-surface elevations (WSEL) at the un-georeferenced
channel centerline locations based on scaling the entire river reach
length between this data and what I have in GRASS. I can use the scaled
distance from the river mouth to spatially interpolate locations where I
know the WSEL.
The GRASS addon command r.inund.fluv needs X, Y, WSEL as an ascii file.
Now if I can go directly from the GRASS vector centerline and output
verticies of that feature, so I have the x,y locations of the verticies
my problem would be solved. I looked at v.distance and other modules but
could not see how to generate the verticies and export them -- but, in
the end, I need an ascii file of centerline point locations in upstream
to downstream order.
v.to.points ? If you only want vertices, use the -v flag.
Moritz
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