Aim What are the features of the Wag water river and how they are formed due to erosion and deposition at each stage of the river? Discussion How tributaries cause the velocity to be greater? A tributary is a stream or river that flows into a main stem river or a lake. Velocity downstream increases when there are more streams feeding the main stream. The load of a river is the total amount of material carried or transported by a river.
The bedload is the load transported along the bed of the river, mainly pebbles, gravel, boulders and coarse materials. These particles will bounce along the river’s bed and the river’s load is derived from its bed and banks wash down on its valley sides and surface creep. The river, when loaded with debris, has a lower velocity, hence there is less energy. There was a tributary in the middle course at Tom’s river hence the velocity was high, the load was transported faster as more energy was available.
The velocity is greater in the lower course. In the upper course there is a lot of energy but it is used to overcome friction caused by obstacles in the river. The Velocity increases as a river becomes more efficient in its lower course or middle course due to the shape of the channel. The velocity depends on the volume and gradient of the slope. The river is deeper, wider and has higher discharge in its lower or middle course.
Relatively less water is in contact with the wetted perimeter, so friction from the bed and the banks is reduced. Channel roughness of pebbles, stones and boulders on the beds and banks increase the roughness of the channel. The wetted perimeter is higher, increasing friction and reducing the friction of the river. Channel roughness is higher in the upper course than further downstream.