River Deposition

Deposition by Rivers

When a river slows down it loses energy which results in it dropping some of its load.  Deposition occurs when a river drops all or part of its load. It occurs when a river does not have enough energy to continue carrying its load either because (i) the river slows down or (ii) the amount of water in the river’s channel decreases.

Ways in which a river can lose speed and energy:

• reduced rainfall - leads to reduced discharge, which results in the river slowing down and having less energy

• increased evaporation or abstraction - reduces discharge, slows the river and reduces the rivers energy

• friction - Shallow areas and areas close to the bank, reduce the river's speed and its energy

• anywhere the river is forced to slow down it loses energy, for example, just before a narrow section

• when a river meets the sea it loses a lot of energy which is absorbed by the sea.