River Features

Question 1

What are the 4 processes of erosion?

Answer 1

Abrasion
Corrosion
Attrition
Hydraulic Acid

Question 2

What is Abrasion?

Answer 2

Fine material in the river hits off the bed and banks, wearing it away like sandpaper.

Question 3

What is Hydraulic Action?

Answer 3

Water enters small cracks along the river bed and banks and its force breaks off small pieces of these.

Question 4

What are the steps of a Waterfall?

Answer 4

When a river flows over bands of hard and soft rack, the rock is less resistant so gets eroded quicker.
This ‘different erosion is done by abrasion/hydraulic action. This makes a ledge which the water flows down.
The erosion of the soft rock undercuts the hard rock, creating a hallow plunge pool with overhanging hard rock.
Ye water flows over the overhang, causing more erosion in the plunge pool through Hydraulic Action.
Eventually the overhang collapses. The process keeps going and the waterfall retreats bank upstream. Over time, this leaves a steep sided gorge.