1

I'm very new to QGIS and would like to create a vector layer and populate it with a number of polygons defined by the latitude and longitude of their vertices in degrees.

I have a base map which is raster, and QGIS seems to display the coordinates of points on this map in a metric format. I'm also fairly happy with the concept of creating a .csv file in WKT format.

My question is, how do I define the vector layer in such a way that it reads the vertices in degrees, not some metric projection?

I'm guessing I have to choose the projection of my vector layer correctly. If so, how do I do that, and which projection is correct for that?

  • 1
    When adding the CSV containing your wkt, choose 4326 for your EPSG-code. Or set the project's CRS (coordinate reference system) to 4326 before importing your data. – Erik Apr 3 at 15:22
  • Thank you for the fast reply! I will try that. – Bennachie Apr 3 at 15:31
  • Can I define the EPSG code in the .csv file? If so, what's the format? – Bennachie Apr 3 at 15:32
  • No, your coordinates are in a CRS (which is represented by an EPSG-code, amongst others). In order for QGIS to know, which CRS it should use when showing your data, shapefiles have a .prj-file. For CSV you have to tell QGIS which CRS to use, when you load the file. – Erik Apr 3 at 15:34
  • Ah, ok. I'll have a go at that tonight or tomorrow. Many thanks once again. – Bennachie Apr 3 at 15:36
2

When loading a CSV file you can tell QGIS, which CRS to use.

Top field is the path to your file, second field can be your layer name, but you don't have to fill it out.

The first triangle opens the options on your data format.

The second triangle allows you to adapt further to your data-structure, this time in respect to the attribute table.

The third triangle gives you options on the geometries, whether you have points or polygons (WKT). Also you may choose the CRS (red box in the attached image). There you have to choose EPSG:4326.

enter image description here

  • That worked perfectly. Thank you very much for your help. I'm sure I'll have more questions in future. – Bennachie Apr 3 at 20:13
  • @Bennachie, please accept the answer if it solved your problem, so that other participants understand that a similar question can solve their problem – PieterB Apr 4 at 11:06

Your Answer

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

Not the answer you're looking for? Browse other questions tagged or ask your own question.