On this wiki page:
https://www.ufopaedia.org/index.php/WORLD.DATThere is this info:
UFO TFTD
0: Forest / Jungle 0: (Nothing?)
1: Farm 1: Pipes
2: Farm 2: Crashed Plane
3: Farm 3: Atlantis
4: Farm 4: Mu
5: Mountain 5: Sunken Galleon
6: Forest / Jungle 6: Sunken Liner
7: Desert 7: Volcanic
8: Desert 8: (Nothing?)
9: Polar Ice 9: Volcanic
10: Forest / Jungle 10: Sunken Liner
11: Forest / Jungle 11: Pipes
12: Polar Seas w/Icebergs 12: Mu
Is there any more detailed info on the UFO terrain types? In game I notice some textures of farmland on the globe produce missions where there are only fields and no houses. Some produce missions where there are many houses. Which is which?
Also, what's are the different types of forest / jungle? Is there any difference between Forest/Jungle types 0, 6, 10 and 11?
Similarly, what is the difference between desert types 7 and 8?
I am modifying world.dat for a mod and would appreciate such info.