Ok, lots of great information here, thanks!
The difficult part of the processing is making sure only the coastline gets buffered, correct? If that’s done manually, do you continue to pull new shapes from GADM as they update the files? The standard places page says iNat uses GADM 2.8, did iNat’s files get updated since then (i.e. GADM is currently at 3.6)?
Is it a long list of places not sourced to GADM? Like if I find an issue with an iNat atlas, 90% of the time it can be traced back to GADM? For example, the Itapiranga problem is actually an issue with the file from GADM:
But the problem with Isla Tortuga in Baja California Sur is not from GADM – their shape perfectly covers the island:
So if I want to correct a GADM atlas issue, what’s the best thing to do? Give a list to you to give to Robert? Use the contact form on the GADM website?
We could do only state level atlases, but I think that would be a lot of lost information, especially with states like Amazonas (~1,500,000 square km).
The other benefit is that frequently political boundaries are also geographic boundaries – things that historically prevented humans from moving around also prevented other things from moving around, so the boundaries often line up fairly nicely with actual ranges. From a user perspective, a political grid is preferable to an evenly spaced grid, despite the implementation issues. There are other grids I could imagine would be useful, e.g. biomes, or with major river boundaries. They would also be hard to implement, but would change less frequently than political boundaries.
Would the best course of action in terms of correcting iNat atlas shapes be to wait and see how this plays out first?