Riparian Environments:River processes

There are 3 main types of river process:

Erosion
Transportation
Depositing

Erosion
The wearing away of rock on the river bed and banks. There are 4 main types: (see BBC bite size

Hydraulic action – the force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.
Abrasion - rocks carried along by the river wear down the river bed and banks.
Attrition - rocks being carried by the river smash together and break into smaller, smoother and rounder particles.
Solution - soluble particles are dissolved into the river.

Transportation
This is the movement of elements by a river. The diagram shows the different methods. the amount of material being carried is really dependent on the energy of the river. The slower it runs the less it transports, such as on plains or near its mouth.











Deposition

As the word suggests as the river slows it deposits material generally as the volume of water reduces say in times of drought or when it slows at the mouth or in a delta. one of the most amazing deltas is the Okavango Delta in Botswana. It is produced by a seasonal flood and as the water meets the plain that only has a height 2 meter height variation it slows and deposits material.



I have obtained much of this information from the BBC Bite size web site. it is a good revision tool available to all.