You never see a river desert in FF because after ~30 turns it automatically turns to flood plains. This can make for example, the calimbam VERY powerful - flauros on grassland, + sun mana, wait a bit, and you suddenly have a bunch of flood plains and can EASILY get size 20-30 cities... which when combined with their govenor's manor's more than make up for the loss of production from scorching plains. Then later when you get vitalize, you can vitalize the flood plains up to plains and grasslands, making for +7 food squares running aristocracy/agrarianism+sanitaion (and with flauros, +4 gold as well).
If this were in orbis, the lack of aristocracy would allow for +9 food squares in late game, +6 the earlyish game (after you have knowledge of the ether and divination if you palace doesn't provide sun mana or you don't have mirror of heaven). It also allows for squares that you can put your cottages on and not need to worry about feeding them, as the 3 food provided pays for 1 citizen. It is also an excelent way to recover a decent city location from what would otherwise be a horrific start.
The specific reason I had asked originally was I ended up with a start with the kurotaes in orbis that was on mostly plains, but with a nice long river running down it. Shortly after though, I got pwned by the barbarians and the dovollio teaming me, and proceeded to play somewhere else. I didn't have time to test my question in that game, and in my later game my start was without river and rather cramped, so I couldn't test it then either.
-Colin
