2B.8

• list 3 ways humans disrupt the sediment cell and increase and decrease rates of coastal recession?

  building dams

  building coastal defences

  dredging
• explain how dams disrupt the sediment cell?

  building a dam on a river can interfere with the movement of sediment through the river, and there will be less sediment for longshore drift

  --> this leads to increased rates of erosion further along the coastline as there is less sediment input into the system
• explain how coastal defences disrupt the sediment cell?

  coastal defences such as groynes can retain sediment in a certain area by preventing its movement along the coast by longshore drift

  --> this increases the size of the beach with the groynes and slows the rate of coastal recession, but starves beaches of sediment further along the coast
• explain how dredging disrupts the sediment cell?

  sand and shingle are used in the construction industry. they are obtained by dredging offshore bars, harbours and beaches

  used to deepen shipping lanes to allow for large ships to dock at port or for beach nourishment projects

  • -> removing sediment from a cell permanently increases recession rates - the removal starves the beaches of new sediment supplies that can reduce the effects of incoming waves
• what are the economic impacts for farmers of coastal recession?

  agricultural land by the coast is less likely to be protected as it has the lowest land value so farmers will lose farmland and therefore income
• what are the economic impacts for local businesses of coastal recession?

  smaller businesses on receding coasts may be abandoned causing job losses for locals, this may impact other small businesses
• what are the economic impacts for residents of coastal recession?

  selling coastal property can be difficult as homes on receding coastlines lose their value very quickly due to their vulnerability and therefore it's often impossible to buy house insurance. This influences the value of other properties that are less at risk and can devalue entire villages
• although these costs are high, coastal recession is usually predictable and happens slowly. contingency funds can be set aside for these costs and it may be possible to make economic preparations in advance of the coastline receding
• Social costs of people living on receding coastlines

  • Forces people to relocate, which can break up communities and cause depopulation
  • Remaining residents may feel isolated, especially if loss of infrastructure leaves them disconnected
  • Area's amenity value can be lost as areas become abandoned, they can lose their character and may become visually unattractive
  • Local services may also close down as people move away, this can affect people on low incomes and those who are less mobile, it may also mean a loss of livelihood to people who normally work in the area
  • Extremely rarely, cliff collapse can lead to fatalities e.g. people walking on unstable cliffs that collapse, also falling debris can injure people on beaches, esp after a storm