Coastal defences and their benefits/costs

?

1. What are the costs of dune regeneration?

  • The protection is limited to a small area. It is very expensive.
  • Taking material from the seabed can kill organisms like sponges and corals. It's very expensive and it has be constantly maintained.
1 of 19

Other questions in this quiz

2. What are the costs of gabions?

  • They starve beaches further down the coast of sand, making them narrower. Narrow beached don't protect the coast from erosion very well.
  • They create strong backwash which erodes under the wall. Expensive to build and maintain.
  • Ugly to look at. The cages can corrode over time.
  • Boulders can be moved by strong waves so the need to be replaced.

3. What are the costs of groynes?

  • Boulders can be moved by strong waves so the need to be replaced.
  • They starve beaches further down the coast of sand, making them narrower. Narrow beached don't protect the coast from erosion very well.
  • Ugly to look at. The cages can corrode over time.
  • They create strong backwash which erodes under the wall. Expensive to build and maintain.

4. What is dune regeneration?

  • Creating or restoring sand dunes by nourishment, or planting vegetation to stabilise the sand.
  • Sand and shingle from elsewhere (e.g from the seabed or from lower down the beach), is added to the upper parts of the beach.

5. What is a sea wall?

  • A wall made out of hard materials such as concrete that reflects waves back to the sea.
  • A wall of wire cages filled with rocks, usually built at the foot of the cliff.
  • Boulders that are piled up along the coast.
  • Wooden or stone fences that are built at right angles to the coast. They trap material transported by longshore drift.

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal zones resources »