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I downloaded a TIFF image from USGS Earth Explorer from which I determined the contour lines and saved them in a shapefile (see tutorial http://www.qgistutorials.com/en/docs/working_with_terrain.html).

I would like to convert these features to points (just as this ArcGIS tool http://pro.arcgis.com/en/pro-app/tool-reference/data-management/feature-to-point.htm).

Each point should contain xyz information (simple CSV file or similar) which I can import as a surface elevation into FEFLOW (groundwater modelling)

I tried with MMQGIS which gives me the following output:

"shapeid","x","y" "1","-7.4266662066","37.1800028654" "1","-7.42583287327","37.1800083477" "1","-7.42582462244","37.1800000968" "2","-7.42583287327","37.1799959509" "3","-7.4266662066","37.1799959509" "3","-7.42749953994","37.1797223191" "3","-7.42833287327","37.1795834302" "3","-7.4291662066","37.1797917635" "4","-7.42999953994","37.1797223191" "4","-7.43083287327","37.1799959509" "4","-7.43083701921","37.1800000968" "4","-7.4316662066","37.1805556524" "4","-7.43208287327","37.1808334302"

What I want however is:

"x","y","z" "Latitude","Longitude","Elevation"

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  • there is the option to export the .shp to .csv using the 'save-as' dialog, and there is the mmqgis plugin, which offers good control over .csv export. but I don't think you can actually export each vertex' z value, as the height is (I guess) only stored as a seperate column as contour level. could you refer to this column later in FEFLOW to get z values? you should also consider exporting the geometries as WKT (it is further explained in other question like this one; gis.stackexchange.com/questions/109553/…)
    – geozelot
    Commented May 12, 2017 at 17:59
  • ah I just saw that I linked a question that asks exactly for a solution without WKT...nonetheless, the right answer is there, too. you'll get both answers for one click, then. nice.
    – geozelot
    Commented May 12, 2017 at 18:23
  • Hi @ThingumaBob! Thank you very much for your response! Unfortunately, this doesn't do it. I modified my question to clarify what I would like to do :)
    – Stücke
    Commented May 12, 2017 at 19:57

1 Answer 1

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In two steps:

  1. Extract nodes. Vector | Geometry Tools | Extract nodes (or from Processing Toolbox QGIS geoalgorithms | Vector geometry tools | Extract nodes
  2. Save As... the produced Nodes layer as csv file. By default, the Geometry type would be Automatic . Make sure the Layer Options is set to GEOMETRY= AS_XY. (So, basically, leave it as is).

NB the extracted nodes can create a big file. Please consider decimating it before saving it to csv.

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  • This still exports the ID which is a little bit annoying but certainly something I can deal with!<br/> X,Y,ID,ELEV -7.45249953993674,37.1912500968475,222308,0.000 -7.45208287327007,37.1916667635141,222308,0.000 -7.45249953993674,37.1920834301808,222308,0.000 -7.45277731771452,37.1916667635141,222308,0.000 <br/> Thank you both for your support!! :)
    – Stücke
    Commented May 13, 2017 at 8:57
  • If you are using recent version such as QGIS2.18, you can select fields to export while saving it to csv.
    – Kazuhito
    Commented May 13, 2017 at 9:04

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