Coastal Management

Question 1

Gabions

Answer 1

Cages of stones used to stabilise cliff bases and absorb wave energy
Only a short term measure and they can be damaged by storms and the cages rust but are effective in the short term.

Question 2

Groynes

Answer 2

Reduce longshore drift by trapping sediment on one side which builds up the beach and acts as a natural barrier to erosion by absorbing wave energy. They can be wooden or rock. They can be effective but look ugly and need regular maintenance.

Question 3

Sea walls

Answer 3

Made out of concrete or stone and made to absorb wave energy. They can be sloped, curved or vertical. They stop the sea reaching the cliff base and reflect wave energy. They are expensive and ugly but are effective.

Question 4

Revetments

Answer 4

Sloping features which absorb wave energy but led water and sediment through. Made out of wood, concrete or stone and placed at the bottom of cliffs. They need regular maintenance and do not protect against big storms

Question 5

Rip rap

Answer 5

Huge boulders of granite or other igneous rocks. They are placed at the foot of cliffs to absorb wave energy and let water drain through them.
It is expensive, ugly and can restrict access to the beach but it can be effective

Question 6

Tetrapods

Answer 6

Made of concrete and their unique shape makes them stable. They absorb wave energy and allows water to drain. They are the first line of defence. They are expensive and can disrupt shipping and wildlife.

Question 7

Why do coasts need protecting?

Answer 7

They are vulnerable areas of great economic value that are at risk of erosion

Question 8

Dune stablisation

Answer 8

Planting vegetation on dunes to make them more stable and reduce moisture content

Question 9

Cliff regrading

Answer 9

Making cliffs less steep to avoid collapsing and undercutting

Question 10

Beach nourishment

Answer 10

Adding sand to a beach and making it bigger to act as a natural defence