Matthew Blissett wrote:

For the other approach, I don't have EPSG:3575-format vector tiles with country borders, but in any case it's difficult to work with vector tiles for any further processing — if you wanted a polygon, you'd need to reconstruct it from the lines which are cut off at the edges of the tiles. I recommend you use a different source of map data, e.g. from http://www.naturalearthdata.com/ . Many GIS libraries (including Javascript ones for display) should be able to work with that data, for example in GeoJSON format:

With some programming, the poly-edge cutting problem can be solved. Besides, on large-scale maps with small polys, I find cutting the poly edges really improves the looks of the map. Also, one could use the country borders to highlight (e.g.) a specific country on the background-map before overlaying the occurrence polys. So, I do suggest adding "&country=" to the GBIF background-map tile API.

https://github.com/nvkelso/natural-earth-vector/tree/master/geojson (if 10m resolution is sufficient).

Thanks !

The Natural Earth Admin0 data sets <https://www.naturalearthdata.com/downloads/50m-cultural-vectors/> are what I need. Best of all, it can be loaded into QGiS and converts perfectly well to EGCS:3575. There is not much on the internet (that I could find) for converting to EGCS:3575. I have only located QGiS, OpenLayers (apparently) and Leaflet (Proj4Leaflet c.s.). And GBIF, of course.

The advantage of EGCS:3575 is that it is an equal area projection <https://en.wikipedia.org/wiki/Lambert_azimuthal_equal-area_projection>, unlike EPSG:3857 Web Mercator. I don't like Web Mercator distortions. I guess EPSG:3857 became polular when Google started to use it, thinking that people will be confused when the line pointing North isn't vertical. God should have made the earth a cube for that purpose ? Well, that causes some problems at the edges when travelling ....

I will investigate the &country=NL issue further and reply seperately.

Regards,

Adriaan van Os

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