River channel processes

What is a process?

An action taking place

What is a river process?

And action taken place in a river

e.g. Erosion, Transportation, Deposition

There are 3 main river processes:

- Erosion

- Transportation

- Deposition

Types of river erosion:

More discharge = more erosion

- Hydraulic action

The force of air & water on the sides of the river in cracks (bubbles of gas)

Includes the direct force of water & cavitation (force of air exploding):

As water accelerates pressure drops and may cause air bubbles to form

Cavitation occurs as bubbles implode & evict tiny jets of water which damage beds + banks

- Abrasion

The wearing away of the beds and bank of the load carried by a river (sandpaper effect)

Effectiveness of abrasion depends on hardness of impacting particles & the resistance of the bedrock

This type of erosion increases as velocity increases

- Attrition

The wearing away of the of the load carried by river. It creates smaller, rounder particles.

This type of erosion happens mainly within the water flow not around the beds & banks

- Corrosion

The removal of chemical ions, especially calcium

This type of erosion is also called solution

Occurs…