What I am specifically trying for is a Nile like world. Hot, arid, desert, with a broad river as a source of fertility and water.
Rivers you can only get via mods right now, and I have chosen RiverGen. By tweaking the config I could get a wide river with few forks, to my liking.
The problem I am running into seems to be vanilla, and something RiverGen does not cover.
Either I make the world hot and arid in the world gen settings, and I get my river with low fertility soil and few trees around it and desert beyond.
Or I make the world hot and humid, and I get my river with medium to high fertility soil and dense trees, but there is no desert beyond it, just more jungle. It does not seems RiverGen config covers my use case, so I'm asking here if anyone knows a setting/mod/config variable that could help me out here.