Coastal Management

• Hard engineering strategies involve using artificial structures to manage coastal erosion
• Soft engineering strategies are a more sustainable and natural approach to manage coastal erosion
• Erosion is a natural process that shapes cliffs and can cause cliff collapse over time, necessitating coastal management
• Sea walls:

  • Concrete walls at the foot of a cliff to prevent erosion
  • Advantages: effective at protecting the base of the cliff, usually have promenades for people to walk along
  • Disadvantages: waves can still break down and erode the sea wall, expensive (approximately £2,000 per metre)
• Rock armour:

  • Large boulders at the foot of a cliff to break waves and absorb energy
  • Advantages: cheaper than sea walls, easy to maintain, can be used for fishing
  • Disadvantages: look different to local geology, expensive to transport
• Gabions:

  • Rocks held in mesh cages in erosion-affected areas
  • Advantages: cheap (approximately £100 per metre), absorbs wave energy
  • Disadvantages: not very strong, looks unnatural
• Groynes:

  • Wooden or rock structures built out at right angles into the sea
  • Advantages: builds a beach encouraging tourism, traps sediment carried by longshore drift
  • Disadvantages: by trapping sediment, it starves beaches further down the coastline, looks unattractive
• Hard engineering management involves using artificial structures, whereas soft engineering management is a more sustainable and natural approach to manage coastal erosion
• Soft engineering strategies involve the use of natural, sustainable solutions to control the coast without building artificial structures
• Beach nourishment:

  • Sand is pumped onto an existing beach to build it up
  • Advantages: blends in with the existing beach, larger beaches appeal to tourists
  • Disadvantages: needs constant replacement, sand has to be brought in from elsewhere
• Reprofiling:

  • The sediment is redistributed from the lower part of the beach to the upper part
  • Advantages: cheap and simple, reduces wave energy
  • Disadvantages: only works when wave energy is low, needs continuous repetition
• Dune nourishment:

  • Marram grass planted on sand dunes stabilises them and helps trap sand to build them up
  • Advantages: relatively cheap, maintains a natural-looking coastline
  • Disadvantages: can be damaged by storm waves, areas have to be zoned off from the public, which can be unpopular
• Erosional landforms along the coastline include headlands, bays, caves, arches, stacks, stumps, and wave-cut platforms
• Depositional landforms include beaches, spits, and bars
• Headlands and bays form when a coastline is made of different types of rock, with soft rock eroding quickly to form bays and hard rock forming headlands
• Cliffs and wave-cut platforms are more common on headlands, while bays are sheltered with constructive waves that deposit sediment to form beaches
• Cliffs are shaped through erosion and weathering, with soft rock forming gentle sloping cliffs and hard rock forming steep cliffs
• A wave-cut platform is a wide gently-sloping surface found at the foot of a cliff, formed by erosion at the base of the cliff between the high and low water mark
• Caves, arches, stacks, and stumps are erosional features commonly found on a headland, formed through processes like hydraulic action and abrasion
• Erosional landforms include headlands, bays, caves, arches, stacks, stumps, and wave-cut platforms
• Depositional landforms along the coast include beaches, spits, and bars
• Beaches are made up of eroded material transported and deposited by the sea, often forming in sheltered areas like bays where constructive waves build them up with a strong swash and weak backwash
• Sandy beaches are usually found in bays with shallow water and low-energy waves, while pebble beaches form where cliffs are eroded and with higher energy waves
• A beach profile has ridges called berms, showing high tide and storm tides, with larger material at the top due to high-energy storm waves and the smallest material nearest the water due to attrition
• Spits are extended stretches of sand or shingle jutting out into the sea from the land, forming when sediment is carried by longshore drift and deposition occurs, creating a long thin ridge of material
• A spit can grow across a bay, joining two headlands together, forming a bar that can trap shallow lakes known as lagoons, which may eventually fill up with sediment