Coastal Defences And Management

Question 1

Give a brief description of the formation of a shoreline management plan

Answer 1

1. UK’s coastline divided into cells and into smaller subcells
2. Shoreline management plan drawn up for each sub cell. Plans try to minimise risk and expenditure
3. Plans outline how the coastline is to be managed and what strategies are to be used
4. Developed and implemented by local authorities and government bodies, having been agreed after discussions with interested organisations

Question 2

Name the 4 management strategies

Answer 2

• No active intervention (No planned investment)
• Hold the line (Maintain current defences)
• Managed realignment (Allow shoreline to move naturally)
• Advance the line (New defences built)

Question 3

Name the 2 types of coastal defences

Answer 3

• Hard engineering

- Soft engineering

Question 4

What is hard engineering?

Answer 4

Deflects the power of the waves using man made structure e.g. Sea wall

Question 5

What is soft engineering?

Answer 5

Uses natural systems such as salt marshes, to absorb wave energy e.g. Beach replenishment

Question 6

Give the pros and cons of groynes

Answer 6

Pros: Maintain beach by interrupting longshore drift
Cons: Not effective if sea levels rise
Eyesore, looks unnatural

Question 7

Give the pros and cons of rock armour

Answer 7

Pros: Relatively low cost
Large surface area dissipating wave energy
Cons: Not effective if sea levels rise

Question 8

Give the pros and cons of beach replenishment

Answer 8

Pros: Causes waves to break off coastline dissipating their energy
Cons: Reduction of beach material down coast can increase rate of erosion

Question 9

Give the pros and cons of revetments

Answer 9

Pros: Slows rate of coastal erosion
Cons: Regular maintenance costs
Not effective is sea levels rise
Eyesore, looks unnatural

Question 10

Give the pros and cons of sea walls

Answer 10

Pros: Recurved to divert wave energy onto incoming swash
Cons: Not effective if sea levels rise
Can be undercut resulting in high maintenance costs
Very expensive (approx. £5000 per metre)