Coastal Management Strategies

• What is hard engineering in coasts?


  • Man-made structures used to protect the coastline
  • Works against nature by deflecting or absorbing the power of the waves so that erosion is reduced or prevented
  • They attempt to prevent erosion
• What is soft engineering in coasts?

  • Natural structures that attempt to absorb the waves energy and work with nature to protect the coast line
  • They do NOT prevent erosion
• Examples of hard engineering in coasts:

  • Sea wall
  • Groynes
  • Rock armour
• Examples of soft engineering in coasts:

  • Beach nourishment
  • Dune regeneration
• Explain beach nourishment (soft engineering) and its advantages/disadvantages

  Sand and shingle from elsewhere e.g. from seabed or from lower down the beach is added to the upper part of beaches

  Advantages:

  • Creates wider beaches which slow the waves
  • Wider beaches also attract tourists which means money for businesses

  Disadvantages:

  • Taking material from the seabed can kill organisms and destroy habitats
  • Expensive as it has to be repeated, £3000 per metre

  
• Explain dune regeneration (soft engineering) and its advantages and disadvantages:

  Creating/restoring sand dunes by planting vegetation to stabilise the sand. Marram grass adapts to growing in sand, and its roots help hold the dunes together and prevent the sand being blown away.

  Advantages:

  • Sand dunes provide a barrier between the land and the sea.
  • Wave energy is absorbed with prevents flooding and erosion.
  • Stabilisation is cheap

  Disadvantages:

  • The protection is limited to a small area
  • Nourishment is very expensive, approximately £2000 per 100m

  
• Explain managed retreat and its advantages/disadvantages:

  Managed retreat allows the sea to flood land, creating salt marshes that absorb wave energy and reduce erosion and flooding naturally

  Advantages:

  • Cheap and sustainable – No costly repairs needed.
  • Reduces flooding and erosion – Salt marshes absorb wave energy.
  • Creates wildlife habitats – Increases biodiversity.
  • Long-term solution – Works naturally

  Disadvantages:

  • Land is lost – Homes, farms, and businesses may be abandoned.
  • Unpopular with landowners – Farmers may lose fertile land.
  • Takes time
  • Not suitable everywhere

  
• Explain groynes and its advantages and disadvantages:

  Wood or rock structures built out to sea from the coast. They trap

  sediment being moved by longshore drift to build up the beach. The wider

  beach absorbs waves, reducing wave attack on the coast.

  Advantages:

  • Build up the beach by slowing down longshore drift
  • Cheap

  Disadvantages:

  • Easily destroyed
  • Some beaches are deprived of sediment
  • Can be easily damaged/can be dangerous

  
• Explain sea wall and its advantages/disadvantages:

  Concrete/rock barrier built at the foot of cliffs or at the top of a beach.

  Has a curved face to reflect the waves back into the sea. Usually 3-5m

  high and are very strong

  Advantages:

  • Prevents erosion.
  • Acts as a flood barrier
  • Create a promenade for tourists to walk on

  Disadvantages:

  • Very expensive around £5000 per metre
  • Need maintaining
  • Creates a strong backwash

  
• Explain rock armour and its advantages and disadvantages:

  Piles of large boulders dumped at the foot of a cliff. The rock force waves to break, absorbing their energy and protecting the cliffs.

  Barges are used to transport the boulders by sea.

  Advantages:

  • The boulders are good at absorbing wave energy
  • Cheaper than sea walls

  Disadvantages:

  • Can easily be moved
  • They need to be replaced frequently
  • Rocks are imported from Norway which can be expensive

  
• Explain what gabions are and its advantages and disadvantages:

  Gabions are wire cages filled with rocks that absorb wave energy, reduce erosion, allow water to drain, and become more stable over time as sediment and plants build up.

  Advantages:

  • Cheap compared to other hard engineering methods.
  • Absorb wave energy
  • Allow vegetation to grow over time, blending into the environment.
  • Can be built quickly and easily

  Disadvantages:

  • Not very strong – wire cages can break over time.
  • Unattractive
  • Require regular maintenance
  • Can be uncomfortable to walk on if placed on a beach