Pevensey Bay Sea Defence Scheme Flashcards
What type of engineering is used at Pevensey Bay?
Soft engineering
What does the type of engineering here do?
Work with the natural physical processes of the area
What are the four types?
beach replenishment, back reprofiling, fencing/hedging, planting vegetation
3 facts about Pevensey Bay
low-lying area, in East Sussex, vulnerable to coastal flooding
Why were other types of engineering not used?
Hard engineering methods were not used because they would ruin the scenic and environmental value of the area.
Why does Pevensey Bay need protecting?
- longshore drift
- over 50km2 of flat land would flood if defences failed
- over 10,000 properties
- tourist area with caravan parks
- main coast road and rail links run along the coast
Which three types of defence schemes have they used?
- beach replenishment
- beach reprofiling
- beach recycling
How and when is the first type of defence used?
BEACH REPLENISHMENT
- material replaced by dredging from seabed and spraying it onto the beach
- done by a specially adapted boat
- done in summer months because this is when there are fewer storms
How and why is the second type of defence used?
BEACH REPROFILING
- in winter destructive waves move sediment down towards the sea
- upper beach levels are low and liable to wave attack
- bulldozers move materials up the beach and reshape it for an even, gentle slope
How, when and why is the third type of defence used?
BEACH RECYCLING
- longshore drift acts like a conveyer belt
- material is moved west to east
- west side becomes increasingly depleted
- large trucks move material back to the western side three times a year
- even profile and no particular part of the beach subject to wave attack
How is the scheme environmentally sustainable?
it works with the natural environment & does not cause damage to the environment
How is the scheme socially sustainable?
the resulting beach of the scheme has amenity value for local people & is an important tourist attraction
How is the scheme economically sustainable?
there are no massive building costs involved
What are the drawbacks of the scheme?
It requires ongoing maintenance, which is expensive.
