Coastal Management

• What are some examples of hard engineering?


  Sea walls, rock armour, gabions and groynes
• What are sea walls?


  Concrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.
• What is rock armour?


  Large boulders placed at the foot of a cliff. They break the waves and absorb their energy.
• what are gabions?


  Rocks are held in mesh cages and placed in areas affected by erosion.
• what are groynes?

  Wooden or rock structures built out at right angles into the sea.
• What are some advantages of sea walls?


  They are extremely effective at protecting the base of the cliff

  Sea walls usually have promenades so people can walk on them and they are not a eye saw
• what are some disadvantages of a sea wall?

  • Waves are still powerful and can break down and erode the sea wall.
  • Expensive - approximately £2,000 per metre.
• What are some advantages off rock armour?


  Cheaper than a seawall and are easier to maintain

  Can be used for fishing
• What are some disadvantages of rock armour?


  The rocks are expensive and harder to transport

  They look different from the local geology therefore are a eyesaw
• What are some advantages of gabions?


  They absorb wave energy

  Cheap as they are approximately £100 per metre
• What are some disadvantages of gabions?


  Not very strong

  They look unatural
• What are some advantages of groynes?


  Builds a beach which encourages tourism

  They stop sediment from being carried by longshore drift
• What are some disadvantages of groynes?


  They look unattractive

  By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.
• What are some soft engineering strategies?


  Beach nourishment

  Reprofiling

  Dune nourishment
• What is beach nourishment?


  Sand is pumped onto an existing beach to build it up.
• What is reprofiling?


  The sediment is redistributed from the lower part of the beach to the upper part of the beach.
• What is dune nourishment?


  Marram grass planted on sand dunes stabilises the dunes and helps to trap sand to build them up.
• advantages of beach nourishment?


  Blends in with the existing beach.

  Larger beaches appeal to tourists.
• Disadvantages of beach nourishment?


  Needs to be constantly replaced.

  The sand has to be brought in from elsewhere
• advantages of beach reprofiling?


  Cheap and simple.

  Reduces the energy of the waves.
• disadvantages of beach reprofiling?


  Only works when wave energy is low.

  Needs to be repeated continuously.
• advantages of dune nourishment?


  Relatively cheap.

  Maintains a natural-looking coastline.
• disadvantages of dune nourishment?


  Can be damaged by storm waves.

  Areas have to be zoned off from the public, which is unpopular.