Coastal Management

Question 1

Groynes

Answer 1

Commonly wooded walls on beaches at a right angle to the coast, to slow down longshore drift movement. they make the beach wider and higher so that waves expend their energy on it and not on the backshore

Question 2

Sea walls

Answer 2

These appear in different shapes parallel to the backshore. Recurved sea walls use the shape of a wave to direct the water onto the following wave, so reducing its energy. stepped sea walls use the pointed edges to break up a wave as it hits the wall, so dissipating wave energy.

Question 3

Rip-Rap

Answer 3

They are boulders (granite) or specially designed concrete shapes. They are resistant to erosion and have a large surface area to break up the wave energy. They are also used to hold back mass movement on an unstable cliff.

Question 4

Revetments

Answer 4

They are sloped walls, often made of wood, placed parallel to the backshore but a short distance in front of it.

Question 5

Offshore breakwaters (reefs)

Answer 5

Rock boulders dropped parallel to the coast in the shallow waters. They absorb wave energy and dissipate waves before they have a chance to damage the shore.

Question 6

Gabions

Answer 6

They are pebbles in wire baskets and put along the backshore as a wall. They absorb the wave energy and reduces the erosion of the backshore.

Question 7

Beach nourishment

Answer 7

Replaces beach sediment that may have been eroded or transported by longshore drift.

Question 8

Cliff regrading

Answer 8

This is when engineers calculate a stable slope angle based on the rock characteristics. This occurs when cliffs are unstable and are prone to sudden collapses.

Question 9

Cliff drainage

Answer 9

Pipes in a cliff to remove water and reduce pressure in the cliff.

Question 10

Dune stabilisation

Answer 10

This is when dunes are repaired with a geofabic or replanting of grasses like marram grass to keep the dune in place.

Question 11

Managed retreat

Answer 11

Where the land is accepted as being washed away/eroded. i.e. buffer zones next to eroding cliffs can be created so that no valuable property is lost.

Question 12

Soft engineering

Answer 12

They are usually more long-term and sustainable, with less impact on the environment. They are also usually less expensive than hard engineering.

Question 13

Hard engineering

Answer 13

It tends to be expensive, short-term options. They may also have a high impact on the landscape or environment and be unsustainable.