Was the availability of farmland and water ever a consideration in planning post-WW2 borders?
https://history.state.gov/historicaldocuments/frus1945v06/d369
This is a referendum going over potential surrender terms for Japan. Dated late 1944.
It treats Hokkaido as an occupied territory, and suggests Japanese civilians and troops must be evacuated from the island. I have no idea why they thought this was something worth doing, but I guess it's possible the Americans considered giving the island back to the native population (Ainu). Or maybe Soviet intervention, though around this time it was unclear if the Russians would even join. Just a few months later, though, in another referendum, it is suggested "Hokkaido" be removed from the terms.
It kind of struck me that Hokkaido was (still is) a breadbasket for Japan. Perhaps the Americans thought separating Hokkaido from Japan would be too taxing on Japan's food situation? I doubt America wanted a perpetually starving Japan (even if the US in 1944\~1945 didn't want a strong Japan again), and helping Japan do massive land reclamation projects to make up for the loss of farmland the size of the Netherlands doesn't strike me as a particularly good idea. It's kind of what happened in North and South Korea due to each Korea being cut off from the other's resources and farmland.
Unfortunately I don't think this is a well discussed aspect in historiography. The only expert I've managed to talk to dismissed the whole question as not having been discussed much back then. I wonder if anyone has covered this in a book/research paper/etc.