1

My problem is that my CRS will not change. I have looked at all the other posted questions regarding a similar problem. However hopefully the screen shots provided will indicate my issue.

Figure 1 --> I downloaded a shapefile with the orginial CRS of OSGB 1936 / British National Grid

Figure 1

Figure 2 --> The data plots bird densities and I want to create a buffer around the selected feature (yellow point) with the Map units selected as either Meters or Kilometers

enter image description here

Figure 3 --> This indicates that in its Original CRS form the Buffer will display the Map units in Meters

enter image description here

Figure 4 --> I know I need to change the default CRS, so I click on the data point --> Export --> Save Feature as

enter image description here

Figure 5 --> I change the default CRS from OSGB 1936 / British National Grid to EPSG:4326 - WGS 84 and save it

enter image description here

Figure 6 --> enter image description here

Figure 7 --> This identifies the bottom shapefile (is the orginal), the middle (is the saved shapefile in the new CRS) and the top shapefile (I uploaded manually, however is the new shapefile CRS as well)

enter image description here

Figure 8 --> When I now open the buffer and input the new shapefile in the WSG84 CRS which I require. the distance Is only available in degrees. Does anyone know what I am doing wrong? Are my CRS projections not changing? I am confused if they are not as my newly changes CRS shapefiles are data points lie in the exact same position as the original data.

enter image description here

  • 4
    you changed the projection from metres to degrees - so it has changed. Your points will always be in the same place as QGIS reprojects them to the project projection (EPSG:27700?) - stop before step 4 and all is fine – Ian Turton Nov 26 '18 at 10:32
  • And the data will be accurate and provide reliable data? – Bodhi Nov 26 '18 at 10:34
  • 1
    So long as your data is in Great Britain (or near by) it is hard to find a better projection. – Ian Turton Nov 26 '18 at 10:37
  • 1
    There is no such thing as a WGS84 projection in metres. Once you have buffered in EPSG:27700 you can convert to WGS84 (EPSG:4326) and have your buffers be in degrees. – Ian Turton Nov 26 '18 at 10:43
  • 1
    that's right exactly as you do above. QGIS will still reproject it to the project CRS for you so it will be in the right place. – Ian Turton Nov 26 '18 at 10:45

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.