Question

How water deposits soil sediment and rock

Answer 1

A river can only carry a load if it has adequate energy. When the energy drops below a certain level, therefore, the load is dropped. In the Thalweg (the line of fastest flow), more load is carried, and this is also where the erosion occurs, adding more load. On the inside of a meander, for example, since the Thalweg is on the outside, the velocity on the inside is very low, and so deposition occurs. On the very inside, water merely trickles past. This is incapable of transporting load, so it deposits it until it is able to carry all of it.