If the river in question goes underground then so be it, the problem that I see is that it splits downstream. Again, if there's some reason for it then that's fine but otherwise it should probably look more like a new river joining up with the other river...ie: have it come from the northeast instead of the southeast.

Overall, I like the look of it...the brown pattern/texture is quite nice. Instead of blood you could put the cartouche there (the banner that holds things like title, scale, compass). Nice job and I hope we see how it progresses.