Processes

Question 1

What 3 directional erosions can occur? (Processes rivers)

Answer 1

Headward erosion
Vertical erosion
Lateral erosion

Question 2

What is headward erosion? (Processes rivers)

Answer 2

• Makes the river longer
• Occurs near the source
• Throughflow and surface run off cause erosion at the valley head

Question 3

What is vertical erosion? (Processes rivers)

Answer 3

• Deepens the river channel

- Occurs in the upper stages of the course

Question 4

What is lateral erosion? (Processes rivers)

Answer 4

• Makes the river wider

- Occurs in the middle and lower stages of the course

Question 5

What are the 5 erosions? (Processes rivers)

Answer 5

corrosion
abrasion
cavitation
hydraulic action
attrition

Question 6

What is corrosion? (Processes rivers)

Answer 6

• Bedload is dissolved by chemical processes

- Carbon dioxide dissolves in water to form a weak acid which reacts with rocks

Question 7

What is abrasion? (Processes rivers)

Answer 7

Bedload rubs and scrapes against the bed and banks to wear them down

Question 8

What is cavitation? (Processes rivers)

Answer 8

• Air bubbles generated in turbulent flow

- Release shockwaves as they burst against the bed

Question 9

What is hydraulic action? (Processes rivers)

Answer 9

Pressure of the water forces air between cracks in the bed and banks

Question 10

What is attrition? (Processes rivers)

Answer 10

Particles and rocks are smashed against each other to make them smaller and rounder

Question 11

What does the velocity of a river provide energy for? (Processes rivers)

Answer 11

To transport materials

Question 12

How can load be transported? (Processes rivers)

Answer 12

Traction
Suspension
Solution
Saltation