Prolly cause It's hard for us to judge it.
Makin rivers isn't really rocketscience.
Just place them and check if it's good. Then IF you need to remake them when u make areas, then do so.
And if we're helping u, it'd meen that We'd have to DL that image and PAINT on it, and I assume there's none who can be arsed with that ^_^
So the tip should be as stated above.
Just place some random Rivers, mountains, jungle, desert etc..
IF you're having problem with Jungle, desert. Please consider using the WORLD, earth's zones. Tropic in middle~ by the equator.
Anyhow, earth if printed with Icelands BOTH absolute-top and absolute-down, no need for you to do that cuz It wont affect anything of gameplay.None knows if Tibian earth is even round or flat ;]
Tho when checking that image I noticed that it looks like loads of desert in the middle, which prolly isn't JUST. well.. Sorta. Anyhow.. I hope this helped.
EDIT: Btw. under the massive Deserts.. is the EQUATOR situated, somewhat darker green colored. Which is rainforests etc.
The geography of Earth is kinda good as Guidelines when it comes to Mapping.