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I've spent 1 week reading literally every thread on this. The closest I've gotten to is this thread: Creating buffer in meters.

I have a QGIS3 workspace with two layers. The first layer is the OpenStreetMap that comes default with QGIS. The second layer is a vector layer from an imported CSV with various coordinates in EPSG4326 CRS. So the map looks like the world with dots all around it.

I want to draw a 1km buffer around each of the points. My understanding is that EPSG4326 is in degrees, and I need a projection in km. But every single tutorial or thread I find only has instructions for specific regions. There is no solution for the entire world.

Anyone have a simple solution to this? I'm confused because it looks like I have to convert everything by timezone? That can't be right. Surely this is a common enough GIS problem that there's a general solution to it.

What if I just converted the long/lat in the csv to UTM format? Would that work or would that be too distorted?

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    Try the lat, lon buffer plugin plugins.qgis.org/plugins/latlonbuffer
    – user2856
    Mar 6, 2023 at 23:48
  • There is no global projected coordinate system that is accurate in distance from any location to any other location (it's not possible). Drawing geodesic circles in 4326 is not quick but pretty easy.
    – Vince
    Mar 7, 2023 at 0:35
  • How do you do that? In ArcGIS Pro, you just click geodesic buffer, set the units to meters, and enter that. Takes 10 seconds. What's the 10 second equivalent of that in QGIS?
    – Hutchins
    Mar 7, 2023 at 1:48

1 Answer 1

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As stated in the comments, a 1km buffer of a point will not be circular when plotted in a global mercator projection of WGS84 coordinates. Calculating the WGS84 coordinates of a 1km buffer is not trivial.

QGIS has a plugin for this purpose. As stated in the comments the Lat Lon Buffer plugin is your best bet. You will need to enable experimental plugins to install it.

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  • Thanks. This is a more general question. It seems like ArcGIS Pro has geodesic, but QGIS doesn't Isn't this a big hindrance to GIS people? Calculating global distances seems like a common GIS application, so if QGIS doesn't have this basic feature, why is it a commonly used program? Or do most GIS people don't work globally? I'm not a GIS person. Just curious
    – Hutchins
    Mar 8, 2023 at 0:40
  • By my understanding, and reading the description of the Lat Lon Buffer plugin, it will give you a buffer of a global point dataset with Geodesic distances exactly as you have requested. Mar 10, 2023 at 4:38
  • QGIS is open source, that means that we hold the intellectual property in commons. As a user you are part of the community. You have the right to freely use and re-distribute QGIS but a responsibility to contribute to its further development. The fact that the community has, so far, only implemented your feature as an experimental plugin suggests it is a niche use case. Mar 10, 2023 at 4:41
  • You are free to fund the development of a new feature. The changelog for each new release of QGIS has a list of all the organisations and individuals who have contributed funding and code. e.g. qgis.org/en/site/forusers/visualchangelog330/index.html Mar 10, 2023 at 4:47
  • Ok thanks. I wasn't aware. But just curious, do most GIS people not work on a global scale?
    – Hutchins
    Mar 12, 2023 at 23:45

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