Coastal Management

Question 1

Why do coastlines need managing?

Answer 1

• Protect them from coastal erosion and flooding due to sea level change.
• Protect homes and businesses from being damaged or destroyed.
• Severe economic and social effects, especially for tourism and industry coastlines.
• Protect natural habitats.

Question 2

What are the 4 coastal management approaches?

Answer 2

Hold the Line
Advance the Line
Retreat the Line (surrender)
Do nothing

Question 3

What is done in ‘Hold the Line’?

Answer 3

Existing coastal defences are maintained and no new defences are set up.

Question 4

What is done in ‘Advance the Line’?

Answer 4

New defences are built further out in sea as an attempt to reduce stress on current defences and possibly extend the coastline slightly.

Question 5

What is done in ‘Retreat the Line/Surrender’?

Answer 5

Move people out of danger zones and allow natural sea flooding to occur.

Question 6

What is done in ‘Do Nothing?

Answer 6

Deal with the effects of flooding and erosion as they come or ignore them. This approach is generally taken where there’s no habitants and nothing of governmental ‘value’ to protect.

Question 7

What are hard engineering techniques?

Answer 7

High technology, high cost, man made solutions. They do little to work with nature and sustainability is a key issue, however they are often more effective.

Question 8

What are sea walls?

Answer 8

Giant walls that span the entire coastlines to reduce erosion and prevent flooding.

Question 9

+’s of Sea Walls

Answer 9

Modern sea walls have a curved structure that reflects waves into incoming waves, breaking them and further reducing erosion.

Question 10

-‘s of Sea Walls

Answer 10

Big, ugly and expensive. They require lots of maintenance and produce a strong backwash which undercuts the wall making their long term effectiveness questionable.

Question 11

What are Groynes?

Answer 11

Low lying wooden walls that extend out to sea.

Question 12

+’s of Groynes

Answer 12

Capture sand that is transported via longshore drift to build up areas of beaches. Build up of beach increases distance waves travel to cliff, therefore lose energy and reduces impact. Relatively soft technique.

Question 13

-‘s of Groynes

Answer 13

Remove a lot of sand from further down drift resulting in thinner beaches more vulnerable to erosion in starved areas.

Question 14

What are Gabions?

Answer 14

Bundles of rock in metal mesh placed at cliff bases.

Question 15

+’s of Gabions

Answer 15

Reduce impact of waves on cliff bases, preventing undercutting. Relatively cheap.

Question 16

-‘s of Gabions

Answer 16

Not very effective and unsightly.

Question 17

What are Revetments?

Answer 17

Concrete (sometimes wooden) structures built along the base of a cliff.

Question 18

+’s of Revetments

Answer 18

Slanted to act as a barrier against wave action. Absorb wave energy to prevent erosion on cliff. Modified to a rippled surface to dissipate wave energy. Don’t require as much maintenance as a sea wall.

Question 19

-‘s of Revetments

Answer 19

Expensive

Question 20

What is Rip Rap?

Answer 20

Rocks and stones placed along the base of a cliff.

Question 21

+’s of Rip Rap

Answer 21

Aren’t bound in mesh so are more slightly.

Question 22

-‘s of Rip Rap

Answer 22

Rocks are susceptible to being moved by the sea.

Question 23

What are Breakwaters?

Answer 23

Offshore concrete walls that break incoming waves at sea to reduce erosive power when they reach the coast.

Question 24

Are Breakwaters effective?

Answer 24

They are effective however they can be easily destroyed during a storm and don’t look particularly nice.

Question 25

What are Tidal Barriers?

Answer 25

Big retractable walls built across estuaries that can also be used as a floodgate to prevent storm surges.

Question 26

Are Tidal Barriers effective?

Answer 26

They are effective but also hugely expensive.

Question 27

What are soft engineering techniques?

Answer 27

Low technology, low cost solutions that work with nature to reduce erosion. They aren’t as effective as hard engineering but are more sustainable and often cheaper.

Question 28

What is Beach Nourishment?

Answer 28

Sand and shingle are added to a beach to widen it.

Question 29

How does Beach Nourishment reduce erosion?

Answer 29

Widen the beach to increase distance waves travel to the cliff, causing them to lose energy and lower erosive power.

Question 30

-‘s of Beach Nourishment

Answer 30

Sand and shingle is normally obtained by dredging which makes these areas of coastline susceptible to erosion.

Question 31

What is Land Management?

Answer 31

Used to help protect and rebuild sand dunes as a natural defence against erosion.

Question 32

How does Land Management work in preventing coastal erosion?

Answer 32

Boardwalks and boundaries are created around dune systems to reduce human impact on dune succession. The dunes must be relatively undisturbed to be effective.

Question 33

What is Marshland Creation?

Answer 33

Used to break up waves and reduce their speed, and hence erosive power.

Question 34

How can Marshland Creation prevent coastal flooding?

Answer 34

Limits the area waves can reach, preventing flooding. Marshes are created by encouraging growth of marshland vegetation such as glassworts.

Question 35

What is Beach Stabilisation?

Answer 35

Used to widen the beach and dissipate as much wave energy as possible before they reach the cliff.

Question 36

How does Beach Stabilisation work?

Answer 36

Involves planting dead trees in the sand to stabilise it and lower the profile of the beach whilst widening it too.