Once again help needed on a map and the courses of Rivers

[Opaste]

Greetings!

I haven't been here in a while due to being dreadfully busy with schoolwork, but lately I've found the time to start working on my fantasy world again, and once again found myself facing many of the dilemmas I was struggling with before. So, I decided to wander to this fine site again in search of answers. I would really appreciate any assistance

Last spring I posted a map here (http://www.cartographersguild.com/re...es-rivers.html) looking for help in putting my map in at least a somewhat realistic shape, and got lots of great advice. Now that I have started working on it again, and have made quite a bit of revisions to the map, I have once again run into the believability issue. Something on my map just feels off somehow.

So that anyone doesn't have to go read the last thread, I'll explain the situation again:

The continent on the map is pretty enormous, 1 centimeter on the map represents a 1000 kilometer stretch of land. Which means both that the great northern forest is absolutely enormous, and that the great river flowing out of the forest and into the south must flow over 4500 kilometers to reach the sea (as opposed to the only 1000 kilometer distance to the northern sea), so there must be some pretty enormous elevation differences forcing the River to make such a detour, but such elevations would create their own difficulties to the forest...

I am aware that having such an enormous forest so far north and practically surrounded by mountains is practically impossible, which is why I've originally handled the issue by making the forest a very supernatural place. It gets much more rain than should ever be possible (due to being very saturated with dark magical energies and such), so this magical solution would certainly explain the impossible location of the forest. But I'm still wondering whether some kind of at least remotely believable explanation for the forest could be possible. I just prefer to avoid magical phenomena in world-building unless it's necessary.

I attached to version of the map here to illustrate my points. One is a modified version of my previous map (sorry about the poor quality of the picture, I did the modifications in Windows paint :p) and the other one is exactly the same, except with some numbers added for clarification purposes.

As you can see, the Great forest (number 3) is surrounded by mountains (number 1) and hills (number 2) in the west, and more hills in the east and north (number 4). I've been thinking that the prevailing winds in the area come from the east, bringing clouds from the ocean and traveling to the west, so the biggest obstacle to the rainclouds would therefore be the eastern hills. So technically if those hills (number 4) were low enough, perhaps the rainclouds could pass over them, flow over the forest, and then be stopped by the western hills which are higher (number 2) and rain down.

But the problem with this approach is that the forest itself must be on a high enough elevation, that the waters flowing out of it can actually cross the massive distance of 4500 kilometers south to the sea. So if for example the forest floor would be 450 meters up from the sea level, the average drop in altitude from there all the way to the southern sea would be only 1 cm for every 10 kilometers. That would mean all the lands the river flows through would be incredibly flat. Could a river even flow on such a flat ground, or would the water just gather there and form a swamp or lake or something? And no matter on how high altitude the forest itself is, the hills surrounding it from the west, north and east must be even higher, or the waters would simply flow to the northern sea. And this in turn comes with the problem that if the eastern hills (number 4) are too high, they would stop any rainclouds from reaching the forest (it is my understanding that even quite low hills can stop clouds and create a rain shadow?).

So the forest must be high enough from sea level to get the water flowing south through the continent, and the hills surrounding it high enough to force all that water to flow south, but still low enough for raincloud to reach the forest from the east.

As a side note, the mountains (number 1) are probably around between 3000 to 5000 meters tall, and if the hills next to them (number 2) are high enough that they will stop most of the rainclouds over the forest, I'm guessing that would make the hilly area between the mountains (1) and the forest (3) really dry. I'm still thinking of placing a few small kingdoms in those dry hills, so I'm wondering how people in those kingdoms could live - presumably trees wouldn't grow on the hills, and farming wouldn't be plausible, so would most of the citizens basically have to be sheep or goat herders? I'm assuming grasses and shrubs would still grow even on such a dry place, so the sheep and goats could eat them, and the people could live by eating dairy products and meat from their sheep and goats. And since firewood would presumably be in a really short supply, how would the people cook their food and heat their homes? Dried animal dung?

I really appreciate any advice you can give