I was looking for a quality apocalypse world so I could do the challenge. My first thought was to strip down Lucky Palms in S3PE and edit it in CAW. My CAW is bugging out for some reason, possibly Windows 10 related. So I persisted for a while with just deleting all the trees and lots. And then it struck me. There's more than one way to skin a cat, and in this case, a much easier way. I should have thought of it before, as I've done a lot of this kind of thing.
I just made an override file for the 4 terrains (3 grass, one kind of scorched dirt) that I didn't want, and replaced then with the main sand colour! I don't know about sharing these files, as they are part of store content, but if anyone wants an apocalypse world, that is all you need to do!
That, and delete lots and lots and LOTS of trees and shrubs. I swear, this world must have more trees than any other. The LOD file when you zoom right out is still green, so that probably needs editing too, but the main part of the job is done.
On with the story! er... challenge.