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I’m quite an inexperienced QGIS user (2.18 on Ubuntu 16.04).

I’m working on an irrigation scheme and for that I need some information on the elevation difference between two points.

Luckily, the project is in Wallonia (Belgium) which has a high resolution DEM (http://geoservices.wallonie.be/arcgis/rest/services/RELIEF/WALLONIE_MNT_2013_2014/MapServer).

I managed to get this map into Qgis using the « Add ArcGIS MapServer layer »(encoding png32).

I’m now trying to clip it (so I then can transform it into a point shapefile which would be usable). I can’t use the raster>extraction>clipper option (I suppose it’s due to some map protection). So I tried to « save the raster layer as… » a .tiff image (not creating VRT) using the extend of the land on which i’m working. It doesn’t work either but in a strange way :

  • First it says that the saving is completed
  • Then it says that my .tif file is not a supported raster file (which is quite strange)
  • Last but not least, it actually doesn’t create any .tif file in the folder I selected

How can I clip this DEM using either a polygon or the map view extent while keeping the original resolution?

PolyGeo
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Dafinger
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    Why not use the WMS version of the service and request a TIFF, it says it's a supported format: http://geoservices.wallonie.be/arcgis/services/RELIEF/WALLONIE_MNT_2013_2014/MapServer/WMSServer?request=GetCapabilities&service=WMS& – nmtoken Jun 24 '18 at 23:27
  • Thanks, I used the WMS-services and it displays the map as well but there's still the problem of saving the raster. Qgis first says that the export to raster file is completed then that my .tiff file isn't a supported data source... – Dafinger Jun 25 '18 at 15:35
  • Looking at this again, it appears the service is misconfigured, for example the BoundingBoxes and ...BoundLongitude and ...BoundLatitude elements are using comma as decimal separator, but dot is expected. e.g have errors like cvc-datatype-valid.1.2.1: '2,835011' is not a valid value for 'double' and Description cvc-type.3.1.3: The value '6,438924' of element 'eastBoundLongitude' is not valid. – nmtoken Jun 25 '18 at 18:54

2 Answers2

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As nmtoken indicates, you can't work directly with WMS-services. You need the data on your drive, so you either request the tiff, or you save the desired extent as a picture (or better several which you later merge).

Erik
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  • Thanks, I used the WMS-services and it displays the map as well but there's still the problem of saving the raster. Qgis first says that the export to raster file is completed then that my .tiff file isn't a supported data source... – Dafinger Jun 25 '18 at 15:35
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Came across this facing the same situation. Noting that a how-to for 2 approaches is given at this related question.

Houska
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