World geojson inaccurate

[damir-fell]

World geojson is very inaccurate in coastal regions. There are several cities, land areas, islands and similar missing in both Norway and Sweden. We have imported this map in our repository and fixed the map for Norway so it includes ALL areas in Norway and we are now extending our usage to Sweden and other countries.

So, my question is if there is any reason that the map is missing lots of land area on the coast and if you would like us to make a PR here to fix the map?

[VIKTORVAV99]

Hey!

It's a pure performance tradeoff we made as there really is no limit to how detailed you can do a coastline (Coastline Paradox). So with this granularity and accuracy we felt it was good enough for what we wanted to do without creating a huge file that contains the map which would reduce performance.

Any particular reason you need higher accuracy on the map?

[damir-fell]

Nordpool do not expose a nice to use map over price areas. At least last time we checked they said they have some CSVs that are publicly available but advised us not to use them due to not being maintained and for internal use.

Therefore we looked elsewhere and found the map you have here. We use the map to decide which price area a given address is in, in order to display price and consumption data properly to our customers. The problem is that with the current geojson a lot of addresses falls out of any area.

We do not really need the accuracy increased, but we need all land areas to be included. So basically we could take the current geojson and extend it x amount of kilometers into the sea and it would work well for us.

Like this example of Stockholm

[VIKTORVAV99]

What we did is just to give every zone a virtual 50km buffer along every coast to resolve any issues with people querying our API with coordinates just outside the GeoJSON border.

You can take a look how we do it here: https://github.com/electricitymaps/zone-finder

Specifically here:
https://github.com/electricitymaps/zone-finder/blob/a0c96f10e687e42eb3f4c36a663753a298e87922/utils.js#L63-L97

[damir-fell]

Interesting, will take a look!

Thanks for linking me to this resource.