Please enable JavaScript.
Coggle requires JavaScript to display documents.
Pevensey Bay - Soft Engineering - Coggle Diagram
Pevensey Bay - Soft Engineering
Background Information
Located on the east Sussex coast
Has a natural shingle embankment from the last ice age, created by processes associated with sea level rise, waves and LSD, which acts as a sea defense
150 wooden groynes removed in 2007
Protection technique is hold the line
Occupies a low lying area of softer sediment between sandstone geology to the east at Hastings and Chalk of the South Downs to the west
Management is organized and maintained by a public-private partnership (PPP) coastal management scheme. This is done by Pevensey Coastal Defense Ltd (PCDL) with an initial budget of £30 million. The protection is for 10,000 properties, he A259 coast road and SSSI wetland site.
Strategies
Beach Replenishment
Disadvantages
Turns constructive waves into destructive waves due to the steeper beach angle
Money will un out and become unsustainable
Removes sediment from other areas
Advantages
Barges stop large amounts of lorry use and road traffic
Cheaper than moving residents
Beach Recycling
There is LSD from W. to E. along the bay
Bulldozes dig up accumulated sand at the E. end of the beach and transfer it to trucks
Trucks take the material back along the beach to the W. end and deposit it
This allows LSD to distribute it along the length of the beach in the year
Beach Reprofiling
This changes the gradient of he beach to best absorb the wave energy.
Winter storms remove lots of the lower beach with their backwash.
Bulldozers spread the sand evenly across the beach in spring to create a more even profile
10 wooden groynes along a 6m high shingle beach extends 5m into the sea
Reasons for Managment
Without embankment there would be 3-4m of flooding
150 groynes have deteriorated and the repair and replacement would be expensive and use lots of hardwood
The beach environment has valuable plant species which need protection
There are coastal homes looking over the beach and their
views need protection
Hard engineering would compromise on the residents wishes, economic costs and sustainability