Coastal Environments on a Local Scale: The Coastal Proceses, Landscape and Sustainable Management of Pevensey Bay, East Sussex

Question 1

What type of land does Pevensey Bay occupy?

Answer 1

It occupies a low-lying area of softer sediments between standstone geology to the east at Hastings and chalk at the South Downs to the west.

Question 2

What has created a natural shingle barrier?

Answer 2

Natural processes, sea level rise and longshore drift over the course of thousands of years.

Question 3

In which direction is the longshore drift action?

Answer 3

From west to east.

Question 4

For how long does the shingle bank extend?

Answer 4

It extends fro 9km between Eastbourne and Bexhill.

Question 5

What has the shingle bank remained as?

Answer 5

It has remained as a natural defence to flooding.

Question 6

Why is it difficult to manage this stretch of coastline?

Answer 6

The settlements need the coast to stay in the same position but it is changing everyday. Climate change is increasing sea levels and storm frequency and it is difficult to balance the costs with the needs of the residents and sustainability.

Question 7

How many properties are protected by the current sea defences?

Answer 7

10,000

Question 8

What is the size of the area that is protected from permanent flooding because of the sea defences?

Answer 8

50km2 and includes the area of Pevensey Bay.

Question 9

What type of sites are being protected?

Answer 9

Commercial and recreational sites.

Question 10

What road is being protected by the sea defences?

Answer 10

The A259 coast road is protected?

Question 11

The train line from Hastings to where is being protected by current sea defences?

Answer 11

From Hastings to Portsmouth

Question 12

What special sites are being protected by the sea defences?

Answer 12

Two nature reserves and a SSSI wetland site.

Question 13

What type of farms are being protected by the sea defenced?

Answer 13

Both livestock and arable farming.

Question 14

Where do the prevailing winds move beach material to?

Answer 14

The prevailing wind moves beach material from southwest to the northeast.

Question 15

What does the prevailing wind create?

Answer 15

It creates beaches that are more parallel to the waves.

Question 16

What happens to the beach profile during major storm events?

Answer 16

The beach becomes flatter which creates beach profiles that reduce wave energy thereby stopping waves from reaching the shingle bank. This therefore reduces the flood risk.

Question 17

What is becoming increasingly irregular?

Answer 17

The movement of sediment is becoming increasingly irregular.

Question 18

What is the net loss of beach each year?

Answer 18

The net loss of beach is 25,000m3 each year.

Question 19

Which is bigger: the risk of erosion or the risk of flooding?

Answer 19

The risk of flooding is bigger here.

Question 20

Why are soft engineering defences more effective?

Answer 20

They are more effective because flooding is the biggest risk and soft man-made defences that are made out of sand and shingle are more effective at breaking up and absorbing wave energy.

Question 21

What is a PPP?

Answer 21

This is a public-private partnership and is the country’s first coastal management scheme to be organised and maintained by this.

Question 22

When did the project begin?

Answer 22

It began in 2000.

Question 23

Why did the project begin?

Answer 23

It began because in 1997 it was realised that there was a 1 in 20 year chance a storm event could breach the shingle beach.

Question 24

Who was the contract awarded to?

Answer 24

It was awarded to a consortium called Pevensey Coast Defence Ltd (PDCL).

Question 25

How long was the project to run for?

Answer 25

25 years

Question 26

What was the initial budget of the scheme?

Answer 26

£30million

Question 27

What has PDCL based its management on?

Answer 27

It has based it on working with the natural environment of the local sediment sub-cell.

Question 28

What is the management an example of?

Answer 28

The management is environmentally and aesthetically acceptable and is an example of a development that maximises opportunities for future recreational and environmental projects.

Question 29

What has maintained the shingle beach?

Answer 29

Traditionally, 150 ageing wooden timber groynes were used but since 2000 the project has removed each groyne as it fails.

Question 30

How many groynes does the project hope to retain?

Answer 30

10

Question 31

What are the 6 beach management strategies that can be seen at Pevensey Bay?

Answer 31

Recharge
Recycling
Bypassing
Reprofilling
Groynes
Beach surveys

Question 32

Explain the recharge strategy.

Answer 32

Lorries transport some of the beach material that has been moved by longshore drift back to the part of the beach where it was taken from, this is dredged from the sea floor just off shore and is a close match to the original sediment. Instead of using noisy bulldozers to push it into place, the material is left in situ and redistributes itself.

Question 33

Explain what is meant by recycling beach material.

Answer 33

Dump trucks redistribute sediment from areas with a net gain to those with a net loss. This is required after storms and when conditions do not allow dredging.

Question 34

What is meant by bypassing?

Answer 34

The southern arm of Sovereign Harbour interrupts the west to east movement of shingle causing it to accumulate. During the winter months the sediment is moved to the west, bypassing the harbour.

Question 35

Why does bypassing take place in the winter?

Answer 35

This is so that tourism is not affected.

Question 36

What is reprofiling?

Answer 36

Destructive waves from winter storms remove shingle from the crest of the shingle beach and deposit it lower down the beach, overtime this sediment will move back to where it originally was but until then the shingle bank is vulnerable. Therefore, a bulldozer pushes the material back up the beach to stop the shingle being transported away by longshore drift.

Question 37

What would the cost of restoring the 150 groynes have been?

Answer 37

It would have taken 40% of the budget (around £12million).

Question 38

Why are the groynes removed when they fail?

Answer 38

This is so that it doesn’t threaten public safety and so that it does not float out to sea. The wood is then used to repair the other groynes or given out to local residents.

Question 39

What do the beach surveys entail?

Answer 39

Twice a month, a quad bike with a GPS receiver surveys the beach. The data is used to produce 3D models of the beach and works like a car satnav but with more accuracy (15-30mm). This ensures the sustainability of the beach and allows the areas that need replenishment, reprofiling and recycling to be targeted.