selsey bill

• where is a sediment cell Selsey bil
• Sediment cell model


  A linked system of sources, transfers and sinks along a section of a coastline
• Closed system


  Doesn't leave equilibrium
• Sediment movement


  Occurs by longshore drift (LSD)
• Sustainable management


  Balance of environmental, economic and social interests
• Sustainable management


  Protect coastal environments while promoting long term viability
• There are problems with sustainable management
• Brighton


  • Middle of the sediment cell
  • Lively coastal area
  • 7 million tourists per year
  • £732 million in tourist revenue
  • 17,500 jobs in tourism
  • High economic value must be protected
• Brighton

  • High levels of erosion
  • High amounts of human activity
• Short-term hard engineering solutions in Brighton


  1. Large sea walls

  2. Groynes
• Large sea walls


  Protect against flooding, wave action, coastal erosion
• Large sea walls are an eyesore to tourists
• Short-term hard engineering solutions

  Significant impact on natural sediment transfer
• Groynes


  Block sediment transfer via longshore drift, stopping it from getting to Beachy Head
• Hard engineering costs more than soft engineering
• Many businesses in Brighton rely on conservation of the coast to ensure an income
• Brighton is expensive to manage
• Brighton's hard engineering affects other parts of the sediment cell
• Beachy Head


  • High environmental value
  • Site of Special Scientific Interest (SSSI)
  • Must be protected by law
  • No coastal defences
  • Prevents construction of hard engineering such as a sea wall
• Beachy Head management plan

  1. Allow unprotected cliffs to erode

  2. Sustainable due to the hard geological nature of the cliffs (chalk)
• Significant cliff erosion at Beachy Head affects the environment and people who own properties in this area
• Between 2005-2015, some areas of habitat were lost and the South Downs Way National Trail was at risk of erosion at Beachy Head
• By 2025, there will be erosion of the cliffs and significant loss of popular footpaths at Beachy Head
• By 2050, Birling Gap will be eroded fully
• Erosion at Beachy Head


  Worsened as limited sediment reaches Beachy Head from Brighton due to groynes and sea walls
• Little sediment reaches Beachy Head from the eroding chalk cliffs due to longshore drift
• Importance of sustainably managing a coastline


  SSSI laws prevent any construction which will damage cliffs and surrounding areas further
• Cuckmere


  • Used to use hard engineering to protect coast but now use adaptive methods
  • Enables the protection of Beachy Head without hard engineering
  • Sediment from Cuckmere to Beachy Head
  • Cuckmere has low economic and environmental value
• Shoreline management plan 2000 for Cuckmere


  1. Allowed Cuckmere to erode

  2. Provides sediment to restart sediment cell

  3. Protects areas with higher value
• Adaptive methods


  • Beach nourishment = add sediment onto beach
  • Managed alignment = coastal defences removed and land erodes
  • Low cost
  • Environmentally acceptable as nothing added to coasts that would contaminate
• Costs of adaptive methods in Cuckmere include eroded beaches, houses, popular footpaths, loss of habitats for animals including badgers, and increased flood risk in villages
• Cuckmere's employment of environmentally responsible coastal management displays the potential for sustainable methods even in eroding areas and provides sediment to areas such as Beachy Head
• Pevensey


  • Soft engineering
  • Shingle bank protects from flooding by laying tyres deep within the ridge
  • Rebuilt and refurbished old sea defences
  • 25-year contract to maintain beach
• Long-term sustainability of coastline


  • Relies on impacts of climate change (rising sea level, more storms, shifting weather patterns)
  • Uncertainty of long-term predictions makes it difficult to make plans ahead
• Priorities for coastal management


  • Protect areas with highest economic and environmental value
  • Ensure long-term beach sustainability
  • Use more soft engineering as seen in Pevensey
• The case study shows the complexity of challenges to sustainably manage a coastline
• The biggest problem is at Brighton, causing problems at Beachy Head as limited sediment transfer
• Balancing economic interests and environmental conservation is a key challenge
• New adaptive methods can help achieve sustainable management, but managing Brighton is expensive and causes further problems down the coastline