1

I have a geoTIFF file (pretty large) covering a good chunk of Spain around Almeria. I got it from the EU-DEM v1.1 data (25m resolution), freely available in which I have a route in lat/long and I want to look up the elevation values at each point or the surface-slope between points, but elevation might be easier.

So far,

  1. loaded the geoTiff in.
  2. figured out how to add a new layer that can be pointed.
  3. installed the point sampling tool and I found a GDAL function called slope that made a slope layer.

But I have no idea how I get QGIS to load in my sample lat/long points? and if that would even work as I see the coordinate system in the bar across the bottom seems to show pixel X, Y.

  • 1
    To extract the elevation value from raster at the sampling vector points, SAGA Add raster values to points (Processing Toolbox | SAGA | Vector <-> raster) will be useful. However, for your ultimate goal, I recommend to investigate Profile tools such as qProf plugin. Slope layer (e.g. GDAL-slope) would not give you the slope along your route (i.e. directional slope). – Kazuhito Aug 28 '18 at 12:44
  • Are your lat/long points in a csv file or an excel table or similar? – Ed Rollason Aug 28 '18 at 18:23
  • Can be either, so whatever is easiest to work with. I can also have regular and very fine data (i.e. we recorded lat/lon position at 10Hz, but also downsample to 1). – Otispunkmeyer86 Aug 29 '18 at 8:27
  • I can also get them into a GPX file too. – Otispunkmeyer86 Aug 29 '18 at 8:57
  • Okay, I was able to load a gpx file in and I can see my route on the map as points and also as a line. I cannot get SAGA Add raster values to points to work. It said the layer was not generated correctly. – Otispunkmeyer86 Aug 29 '18 at 9:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.