Question

give reason the river a Swift at their sources and slow down in the middle and old courses. please give me the answer it is so important

Answer 1

A river's course can be divided into three stages; upper, middle, and... probably because the sediment is slowing it down; there's more friction in this smaller channel. The upper course is characterized by large angular sediment, narrow shallow channels, vertical erosion and low velocity. Common land  forms include waterfalls, gorges, V shaped valleys and interlocking spurs. Meanders are found in the middle course and the channel becomes wider and can migrate through lateral erosion. In the lower course sediment becomes smaller, rounder and smoother, channels are wide and deep and velocity is high in the channel. Common land forms are floodplains, levees and oxbow lakes. Estuaries or deltas are found at the mouth of some rivers.  

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