Question

Explain the erosional work and depositional work of water.
(Please answer it fast!!!)

Answer 1

The energy in a river causes erosion. The bed and banks can be eroded making it wider, deeper and longer.

Headward erosion makes a river longer. This erosion happens near its source. Surface run-off and and throughflow causes erosion at the point where the water enters the valley head.

Vertical erosion makes a river channel deeper. This happens more in the upper stages of a river (the V of vertical erosion should help you remember the v-shaped valleys that are created in the upper stages).

Lateral erosion makes a river wider. This occurs mostly in the middle and lower stages of a river.

There are four main processes of erosion that occur in rivers. These are:

hydraulic action; 

abrasion / corrasion;

attrition; and

corrosion.
Deposition is the process of eroded material being dropped. This happens when a river loses energy. A river can lose its energy when rainfall reduces, evaporation increases, friction close to river banks and shallow areas which leads to the speed of the river reducing and therefore the energy reduces, when a river has to slow down it reduces its speed (and ability to transport material) and when a river meets the sea

Answer 2

When water comes down from the mountain it erodes the soil there and when they come down they put the eroded rocks and soil on the river bank