Section C: Coastal landscape's

• Soft engineering defences

  • Beach nourishment - sediment is put pack onto the bay to create a buffer between land and sea
  • Beach reprofiling - bulldozers push sediment back up beach to create buffer between land and sea
  • Managed retreat - Low value areas of coast are left to flood and erode
• Beach nourishment

  Advantages

  • cheap
  • local material can be used to look less strange

  Negatives

  • If there's storms they will need replacing
  • Offshore dredging damages seabed
• Beach reprofiling

  Advantages

  • cheap compared to hard engineering
  • beach for tourists and land behind is protected

  Negatives

  • Beach has to be shut whilst work is done
  • Can be expensive if major reprofiling is required
• Managed retreat

  Advantages

  • Reduce flood risk
  • Creates wildlife habitats

  Negatives

  • compensation for land is required
• Types of erosion

  Attrition - Rocks hitting together eroding each other and become smaller/smoother

  Abrasion - Rocks hurled at base of cliff to break pieces apart

  Hydraulic action - Water forced into cracks of cliff and pressure makes cracks expand

  Solution - A chemical reaction that dissolves rock
• Mass movement - A large movement of soil and rock debris that moves down slopes in response to the pull of gravity in a vertical direction
• Mass movement process

  1. Rain saturates the permeable rock above the impermeable rock making it heavy
  2. Waves or a river will erode the base of the slope making it unstable
  3. Eventually the weight of the permeable rock above the impermeable rock weakens and collapses.
  4. The debris at the base of the cliff is then removed and transported by waves or river.
• Types of mass movement

  • Rockfall - bits of rock fall of cliff face usually due to freeze-thaw weathering
  • Mudflow - saturated soil flows down a slope
  • Landslide - large blocks of rock slide down hill
  • Rotational slip - Saturated soil slumps down a curved surface
• Gabion

  Walls of cages full of rocks usually at foot of cliff. They absorb wave energy and reduce erosion
• Beach nourishment

  Addition of large amounts of sand or shingle to original beach
• Which type of wave deposits sand on a beach

  Constructive