Anonymous - 2012-03-20


I would like to create easily readable profile data to analyse slopes of a
river. I have tried using the tool "Profiles from lines" (Terrain analysis),
which basically works well. However, for my purpose, the spacing of the
sampling-points is much too small in relation to the rather coarse altitude
grid I'm working with. I don't see any option to change the sampling
intervalls, so I'm looking for other workflows that would allow me to get the
results I require.

My goal is to have a table with not too many values. Ideally, the profile
would not be based on points at regular intervalls along the line in planar
(xy), but with points at regular intervalls along the altitude gradient (z
values from grid). For example, a profile table with sampling points at every
10 m change in altitude.

Originally I had intended to achieve my profile by intersecting the river-
shape (line-shape) with contour-lines (line-shape), but there doesn't seem to
be a way to achieve this with SAGA-GIS. So I've tried using a workflow with
raster-altitude-data, but got stuck again.

Anybody have a suggestion for a workflow for me? If I didn't express my goals
clearly enough, please tell also, I'll try to explain in more detail. Many
thanks for your time and help.