While trying to find a way to find "valleys/ridges" within a DEM, I'd like to know if there are tools, plugins or "methods" known or available to automatically generate height profiles along a given path.

Or maybe a tool that (allows to) calculates the height profile (UNIX preferred, no Windows at all) at a certain position, takin coords and azimut as input?

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Even though I'm yet not used to sextante and GRASS at all, I've searched and read a lot. Shouldn't it be possible to solve above discribed problem by using the sextante modeller?

If there is a single line within a line-shape plus a raster elevation map...

Shouldnt it be possible to...

  1. Step: generate points using v.segment with direction (within line) as attributes for the resulting points P.
  2. Step: generate 2 new points for every P within a fixed given distance, which mark the start and end of an orthogonal line (angle from "directon" at step-1), where P is the middle resp. point of intersection.
  3. Step: calculate profile of this orthogonal using r.profile
  4. Step: write/append elevation profile to a CSV with lat/lon/height x/y/elev, so that it can be further processed or simply beeing 3D illustrated via Speadsheet, gnuplot,..

The lan/lot is delete cause I didnt point out I would like to have it "straightned". Otherwise I could simply wrap the area from the DEM.

An please - as mentioned - I'm new to GRASS and even less when it comes to the modeller :-/ It's not too long ago I started using the sextante toolbox to improove the possibilities within QGIS.

Below show my two rasters examples. First one is straight ASTER elevation data overlayed by a rugh drawn line from a geological map, respresenting a tectonic fault.

Second on is the terrain convergence index (tci) of the DEM, where I get the impression that I can see this line.

ASTER elevation data

terrain convergence index

1 Answer 1


Please look for existing answers prior to asking a question. You can find all the answers and tools for QGIS and GRASS in this existing thread

EDIT: But still need a Height Profile? Google Earth maybe has something like this and is also available for Unix/Windows and co.

  • I ment something like a tool, which not only genrates a point layer from given lines, but far mor somethin that generates 90°/rectangular line-profiles based on a given line. Example: Give a path through a valley and the result will be a set of profiles at coord xy with azimuth z, producing a new layer with a 90° vector and elevation attribute. Dec 17, 2012 at 23:28
  • 1
    Sorry, I guess I didn't point out at all that I mean the profile 90° to the path! Dec 17, 2012 at 23:30

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