Advice needed concerning a fantasy map and the courses of rivers :)

[Opaste]

Good evening to you all By some lucky coincidence I happened to stumble upon this forum just today, and this seemed like such a great place that I simply had to register

I hope I made this thread in the right section of the forum, but if not, I sincerely apologize for my newcomer's ignorance :p

I have been writing fantasy stories (that have all tragically gone unpublished :p) ever since I was ten (so 18 years now), and have been working on my fantasy world for about as long, which needless to say has gone through a great number of changes and revisions over the years. I have been growing increasingly aware and embarrassed of all the completely unrealistic aspects of my world maps, so little by little I've tried to re-design them to have them make at least some kind of sense. Unfortunately part of the problem is that I laid down some of the most important corner-stones of my maps back when I was a kid who didn't have a slightest clue about climatology (or anything else for that matter :p), and I don't want to change them unless I absolutely have to, so I have had to change the rest of the map to try to have those important map elements make any sense. Not really an ideal way to approach map-making :p

Anyway, today I drew a rough sketch of the latest design for one of the continents in my world, and I would be very grateful for any advice I'm especially worried about all those rivers, since my knowledge of hydrology is quite lacking.

That map is hand-drawn with colored pencils, and unfortunately the scanning process wasn't very kind to the colors, but hopefully the map is still clear enough.

A few important notes about the map:

- As you can see from the bottom of the map, the scale of the world is pretty huge (1 centimeter on the map is 1000 kilometers), and the world has a second continent which is actually slightly larger, so the planet probably end up quite a bit bigger than Earth. I'm aware that this might seem excessive, but I like to have enough room where to put all my different countries :p There is of course the risk that adding both those land masses and all those seas together I may well end up with a cylindrical planet, but there's an ocean to the west that i can pretty much make as wide or narrow as I need to so the planet still ends up as a sphere.

- Winds blow a huge number of rainclouds from the western ocean all the time, so the western shoreline gets great amounts of rain (on the eastern side of the mountains is mainly deserts and savanna). However I haven't quite figured out how that huge lake on the southern part of the central plains (the one located in that "bowl" in the mountain range) gets its water. Especially since I've been toying with the idea that the land around the lake and river could be mostly swamps and marshlands, but that would require insane amounts of water, and the plains probably can't get nearly that much rain. Any suggestions?

- That large forest in the northern part of the continent is pretty problematic, since it has been in all my maps from pretty much the beginning, and realistically speaking the forest would probably never get enough rain in order to exist. So I came up with the idea that it really shouldn't exist, it's an anomaly in the world (I've always intended the forest to be a very nasty place, so this actually fits quite well), and the forest seems to create heavy rainclouds out of nowhere, so it's almost always raining there against all logic. This also nicely explains where that massive river that flows south all the way through the central plains gets all its water. I usually hate to explain anything with "a wizard did it!", but in this case it might just work. Also note inside the forest the "ridge" of hills which runs from North-West to South-East, and acts as a watershed (which is why lots of the water flows south, and the rest flows into the northern sea). Unfortunately that large river flowing to the south is one of the most important aspects the map, and I've mostly designed the most important countries around it, so I desperately tried to make it somewhat realistic that all that water goes to the south instead of the western sea (which is much closer) by adding more and more hills on the western side of the river to act as a watershed.

- Also somewhat problematic is the smaller river system on the east side of the great northern forest over the mountains. Once again I tried to use hills to channel part of the rainwater into the south instead of the closest sea (since I pretty much need that river to flow south and join up with the massive river in the center of the continent), but does that look too strange? If so, are there any better ideas to get that river flowing to the south from the mountains?

Thank you very much for any advice you can give

-Opa-

EDIT: There was supposed to be a little thing below the map to show it's scale, but it seems I've managed to accidentally crop it out of the picture. I've meant 1 centimeter on the map to represent about 1000 kilometers, so the continent seems to be over 8000 kilometers wide. I might have overdone it a little, but at least my countries won't run out of space :p