What is the difference between mountain and lowland rivers?

Plain rivers differ from mountain rivers, first of all, by the flow rate. Since the rivers flow along the slopes in the mountains, because of the large angle, the speed of the water is much higher than in the plains, where the angle of incidence is minimal. Also, flat rivers are characterized by an even flow, the absence of rapids, waterfalls and convolutions, while mountain rivers often fall from huge heights, where the slope breaks off at an almost right angle. The water of mountain rivers, failing to break through very hard rocks, bends around them, which is why the flow becomes uneven.