Coastal Management Strategies

Question 1

Name the four hard engineering strategies.

Answer 1

Sea walls, groynes, gabions, rock armour.

Question 2

What are sea walls?

Answer 2

Commonly a concrete structure placed at the top of a beach or foot of a cliff to act as a physical barrier to the sea, preventing erosion or flooding.

Question 3

What is the cost of a sea wall?

Answer 3

Up to £1 million per 100 metres.

Question 4

What are the advantages of a sea wall?

Answer 4

Effective ​
Often has a walkway or promenade for people to walk along.

Question 5

What are the disadvantages of a sea wall?

Answer 5

Can look obtrusive and unnatural.​
Very expensive and high maintenance costs.

Question 6

What are groynes?

Answer 6

Timber or rock structures protruding into the sea at right angle to the coast. Sediment is trapped between the groynes, broadening the beach and affording greater protection to the coast by absorbing wave energy.

Question 7

What are the costs of groynes?

Answer 7

£150,000, each at 200 metre intervals.

Question 8

What are the advantages of groynes?

Answer 8

Create wider beach, which can be popular with tourists.
Provide useful structures for people interested in fishing.
Not too expensive

Question 9

What are the disadvantages of groynes?

Answer 9

By interrupting longshore drift they starve beaches further along the coast, often leading to increased rates of erosion elsewhere. The problem is therefore shifted.
Groynes are unnatural.​

Question 10

What is rock armour?

Answer 10

Large, extremely tough boulders placed at the foot of a cliff or against a sea wall, forcing waves to break early, reducing their energy and protecting the coast from their full force.

Question 11

What is the cost of rock armour?

Answer 11

£200,000 per 100 metres.

Question 12

What are the advantages of rock armour?

Answer 12

Relatively cheap and easy to maintain.
Can provide interest to the coast.
Often used for fishing.​

Question 13

What are the disadvantages of rock armour?

Answer 13

Rocks are usually from other parts of the coastline or even from abroad.
Expensive to transport.
Do not fit with the local geology.

Question 14

What are gabions?

Answer 14

Wire cages filled with rocks commonly built up against a cliff to add support and reduce erosion. Being permeable, they improve cliff drainage.

Question 15

What are the costs of gabions?

Answer 15

£50,000 per 100 metres.

Question 16

What are the advantages of gabions?

Answer 16

Cheap to produce.
Improve drainage of cliffs​
Eventually become vegetated.

Question 17

What are the disadvantages of gabions?

Answer 17

Unattractive.
Only last 5-10 years before they rust. ​

Question 18

Name the four soft engineering strategies.

Answer 18

Beach nourishment, dune regeneration, dune fencing and coastal realignment & monitoring.

Question 19

What does beach nourishment involve?

Answer 19

The addition (feeding) of sand or pebbles to a beach to increase its height and/or width, providing protection from erosion or flooding by absorbing wave energy.

Question 20

What is the cost of beach nourishment?

Answer 20

£500,000 per 100 metres.

Question 21

What are the advantages of beach nourishment?

Answer 21

Relatively cheap and easy to maintain.​
Blends in with existing beach.​
Increases tourist potential.

Question 22

What are the disadvantages of beach nourishment?

Answer 22

Needs constant maintenance unless structures are built to retain the beach.

Question 23

What does dune regeneration involve?

Answer 23

Plants such as marram grass can be sown to stabilise sand dunes and encourage them to develop, acting as a natural buffer to the sea.

Question 24

What is the cost of dune regeneration?

Answer 24

Approximately £2,000 per 100 metres.

Question 25

What are the advantages of dune regeneration?

Answer 25

Maintains a natural coastal environment that is popular with people and wildlife.​
Relatively cheap.

Question 26

What are the disadvantages of dune regeneration?

Answer 26

Time-consuming to plant the marram grass and fence areas off.​
Can be damaged by storms.

Question 27

What does dune fencing involve?

Answer 27

Fences used to protect dunes from human use, to prevent erosion from trampling and other activities.

Question 28

What are the costs of dune fencing?

Answer 28

£2,000 per 100 metres.

Question 29

What are the advantages of dune fencing?

Answer 29

Minimal impact on natural systems.​
Can control public access to protect other ecosystems.​

Question 30

What are the disadvantages of dune fencing?

Answer 30

Can be unsightly especially if fences become broken.​
Regular maintenance needed specially after storms.

Question 31

What does coastal realignment & monitoring involve?

Answer 31

Deliberately allowing the sea to erode or flood an area in a controlled way.

Question 32

What are the costs of coastal realignment & monitoring?

Answer 32

Depends on land value –between £5,000 and £10,000.

Question 33

What are the advantages of coastal realignment & monitoring?

Answer 33

Cost-effective where hard and soft management strategies are targeted at expensive land.

Question 34

What are the disadvantages of coastal realignment & monitoring?

Answer 34

Loss of natural habitats. ​