Gravity pulls the stream channel downward.
A river channel is formed by rock and soil of a stream being transported down, during this process the channels become wider and deeper.
mature.
channel
channel
It cuts a wider, shallow channel .
A mature river
the river becomes excited and becomes wider deeper and more wet
The stages of stream development are youthful, mature, and old age. In the youthful stage, the stream has a steep gradient with a narrow, V-shaped channel. In the mature stage, the stream has a meandering channel and a wider floodplain. In old age, the stream has a very flat gradient, a wide meandering channel, and a broad floodplain.
A mature river erodes its channel wider rather than deeper. The gradient of a mature river is less steep than young rivers, and the water flows more smoothly. Examples of mature rivers are the Thames, Mississippi, and Ohio rivers.
A youthful river is a river with a steep gradient that has very few tributaries and flows quickly. Its channels erode deeper rather than wider.
A stream that is longer and wider is usually considered a BROOK or a RIVER.
A river that erodes its channel deeper rather than wider is typically classified as a narrow, steep-gradient river, often found in mountainous or hilly regions. These rivers possess a high flow velocity, which increases the force of water against the riverbed, leading to vertical erosion. This process deepens the channel as sediment is carried away from the bottom rather than from the sides. Consequently, such rivers create V-shaped valleys, contrasting with wider, meandering rivers that erode laterally.