I got a quick shot at the script.

I have an issue with rivers indeed. Many of them start in deserts or desert borders (including desert/desert/plain tiles, or in the middle of desert hills).



Here's an example (strat view and 3d view).



There are many rivers originating in a hill desert. It looks weird. Another spot on the same map had a large river running into a desert and being joined there by small affluents that were only 1 tile long but originated in a desert/desert/plain tile (with no forest, jungle or marsh).



I think it's a bit too many rivers in deserts. Marshes are also very rivery, and that would be fine except it results in lots of short/average parallel rivers and no complex river system like Amazon, Mississipi or the like.

Click to expand...