[GRASSLIST:3369] Re: Calculating cumulative change in elevation.

[Rod Paterson]

Ben,
        You could use v.to.rast to convert each vector line to a site list using
the Dmax option to set the distance between vector nodes to a distance a bit
less than the elevation raster cell size and then run s.sample using the new
site list and the elevation raster and option attr=none. This will give you a
new site list with the elevation values for each site (point along your vector).
>From there you could export to a spreadsheet and sum the positive and negative
elevation differences along your road/track or use R?

   regards
   Rod Paterson

-----Original Message-----
From: Ben Logan <ben at wblogan.net>
To: The GRASS list <grasslist at baylor.edu>
Date: Monday, 25 March 2002 14:26
Subject: [GRASSLIST:3367] Calculating cumulative change in elevation.


>I have a raster elevation map (imported DEM) and a vector map
>representing roads.  I would like to use the elevation data to find
>the total (cumulative) distance you would ascend/descend in traversing
>a particular line.  Note that I'm not talking about just the
>difference in elevation between the start and end points.  Also, the
>vector map would only contain the one path to follow.
>
>Can anyone suggest a way to do this in GRASS?
>
>Thanks,
>Ben
>
>--
>Ben Logan: ben at wblogan dot net
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