Finding number of mountains between two points using QGIS?

Question

How can find the number of mountains that is crossed by a line between two points on a map?

could you include what software or programming language do you want to use? and if you want to use a script what you already have tried — LaughU, Jan 10 '18 at 14:05
@LaughU I supposed, for link question, that software is QGIS. — xunilk, Jan 10 '18 at 14:19
@LaughU Sorry I forgot to add, I use qgis. I'm a total newcomer so I haven't tried anything, but I thought I could modify the answer that I linked in my question somehow. — Bora M. Alper, Jan 10 '18 at 14:20
Have you decided what constitutes a mountain? As in what would you consider a mountain or a hill? — Keagan Allan, Jan 10 '18 at 15:29
@boramalper You can use "Profile Tool" QGIS plugin. Install it as it is usual (Plugins -> Manage and Install Plugins). Please, see my answer. — xunilk, Jan 10 '18 at 19:10

score 1 · Answer 1 · answered Jan 10 '18 at 17:25

NOTE UNTESTED

This is a methodology I once came across once to identify ridgelines. It might be a good start.

An option would be to try this.

Take your surface (DEM) and multiply it by "-1". The purpose of doing this is to invert the elevations of the raster.
Take this new surface and run it through the hydrological tools in GRASS / SAGA to generate a river vector file. I am unfamiliar with the QGIS / GRASS methodology to do this, but simplistically in ESRI software you calculate flow direction, flow accumulation and convert to river.
This derived river file could be seen as the ridge-lines of your mountain range. Buffer it by 5m to make a polygon.

With the new polygon layer you can try the methodology provided in the link in your question.

score 0 · Answer 2 · answered Jan 10 '18 at 19:09

You can use "Profile Tool" QGIS plugin. Install it as it is usual (Plugins -> Manage and Install Plugins).

Afterward, I tried plugin out with following layers (line shapefile and raster DEM):

With your DEM as active layer, click at plugin icon and add raster layer with "selection" in "Selected polyline". It looks as following image:

Afterward, select line layer as active and click in whatever point of Map Canvas to get some similar to following image:

Now, you can use your own criterion for selecting how many mountains you observe in generated profile.

2 Answers2