Deposition – Occurs when material being transported by the sea or a river is dropped as waves or current slow down due to loss of energy
The position (deposition) is that when he loses energy, she will be dropped.
Deposition occurs when the sediment, or particles, are not moving fast enough in the water.
You absolutely will not need the graph below but it shows you that some clever person has measured that:
A. A piece of sediment of 0.1mm in diameter will drop to the river/ocean floor when moving at just less than 1cm/s.
B. A piece of sediment of 1mm in diameter will drop to the river/ocean floor when moving at just less than 10cm/s.
As waves and currents slow and lose energy, the material they carry sinks and is deposited (hence the word "deposition").