River processes

Question 1

Abrasion

Answer 1

Bedload material is dragged across the river channel and erodes it in a sandpaper style motion.

Question 2

Solution/corrosion

Answer 2

Acids in the river water break down the channel sides and cause erosion to occur.

Question 3

Hydraulic action

Answer 3

High pressure water forces its way into cracks in the river channel and causes a rise in pressure. This causes the crack to widen and material to be eroded from the channel.

Question 4

Attrition

Answer 4

Bedload material knocks together as it is moved by the water in the river. This causes the material to be broken down into smaller and more rounded pieces.

Question 5

Traction

Answer 5

Transportation method through which material is moved by being rolled along the river bed. This is how the heaviest bedload material is moved.

Question 6

Saltation

Answer 6

Material is bounced along the river bed as it is light enough to be picked up but not light enough to be carried constantly.

Question 7

Suspension

Answer 7

Smaller (sand sized) particles can be carried by the river in suspension. These float along without touching the channel bed or banks and makes the water a brownish colour.

Question 8

Solution

Answer 8

Minerals from the bed/banks/bedload are absorbed by the water in solution. These are invisible and only noticed when water composition is tested.

Question 9

Deposition

Answer 9

The is the process through which bedload material is dropped (deposited). It occurs when the river’s energy is no longer great enough to allow the material to be moved.