Coastal Management Strategies

• • Coastal management is essential to build resilience in coastal communities around the world
  • Climate change, increase tropical storm intensity, more frequent storm surges and sea level change are increasing the rates of coastal erosion and flooding
  • These hazards need to be adapted to, as they are already happening in many places
• • Preventing coastal erosion through hard engineering is generally effective but it is very expensive
  • Hard engineering can also often be unsightly
  • There are lots of different hard engineering strategies, to decide which is most appropriate in a particular area a cost benefit analysis must be carried out
  • Some areas are left with no protection because the costs are deemed to outweigh the benefits
• Groynes

  Structures built perpendicular (at right angles) to the shore. Sediment is trapped as it is transported by longshore drift. The beach builds up which absorbs wave energy

  • Not as expensive as other hard engineering structures
  • Builds up the beach which improves tourist potential

  
  

  • Causes sediment starvation further along the coast
  • Can be unattractive
  • Need lots of maintenance to ensure sediment isn’t getting through any holes or cracks
• Sea Walls

  Walls with a curved or stepped surface that absorb and reflect wave energy

  • Highly effective
  • Can have tourism benefits as walkways are created

  
  

  • Very expensive to build and maintain - £6000 per metre
  • Are ugly and intrusive to the landscape
• Rip Rap/ Rock armour

  Large concrete or granite boulders at the foot of a cliff. The spaces in between the boulders cause waves to bounce between many surfaces, reducing the energy of the wave

  • Cheaper than sea walls
  • Used for recreation such as fishing

  
  

  • Dangerous when people are on them
  • Rocks from elsewhere are intrusive to local geology
• Revetments

  A sloped or ramp like structure that breaks up wave energy

  • Cost effective compared to other hard engineering strategies

  
  

  • Need lots of maintenance
  • Unnatural looking
  • Slopes are dangerous
• Offshore Breakwater

  Rock barrier a little out to sea from the shoreline. This breaks the waves and dissipates their energy before they reach the coast.

  • Effective

  
  

  • Away from the beach so does not disrupt tourist potential
  • Can create a navigation barrier in harbour areas
• • Soft engineering works with natural processes and material
  • Soft engineering methods can be an integral part of the management strategy, in order to adapt to sea level change as well as coastal erosion, through developments such as salt marshes
• Beach nourishment/ replenishment

  Adding sand or shingle to a beach to widen it - this creates more surface area to absorb wave energy

  • Looks very natural
  • Bigger beaches are good for tourism
  • Relatively inexpensive

  
  

  • Material is constantly subject to erosion and longshore drift so lots of maintenance and monitoring is needed
  • Dredging the seabed can have impacts of local ecosystems
• Cliff Regrading and Drainage

  Reducing the angle of the cliff to stabilise the slope. Drainage of water also stabilises the cliff against mass movement

  • Cost effective

  
  

  • Can look unnatural as the cliff is unnaturally flatter
  • This effectively creating cliff retreat
  • Dried out cliffs can collapse
• Dune stabilisation

  Planting species like Marram grass so that the roots bind the dunes. The dunes absorb wave energy and protect the land behind.

  • Cheap and sustainable
  • Creates habitats for wildlife
  • Maintains a natural environment

  
  

  • People walk on the dunes and damage them
  • Planting is time consuming and it takes time for plant species to become established
• Marsh Creation

  This is a form of do-nothing or managed retreat. Land is allowed to be flooded by the sea and then left to become a salt marsh. This absorbs wave energy and also creates a buffer to rising sea level and projects higher value land.

  • A cheap option
  • Creates important and unique wildlife habitats

  
  

  • Agricultural land is lost which creates a need for compensation
• Sustainable Management

  • Sustainable management of the coastal zone is wider than preventing erosion
  • It involves a range of strategies including:
  • Mitigation of flood and erosion risk using a range of techniques
  • Adaptation to erosion and flood risk
  • Education of local communities
  • Supporting livelihoods dependent on the coastal zone such as fishing
  • Monitoring of coastal changes
• • Integrated coastal zone management (ICZM) is based on the idea of sustainable coastal management
  • As well as targeting all the areas listed it also seeks to resolve conflicts which may occur
  • Conflicts occur as a result of sustainable management because:
  • Farmers may lose productive land due to managed retreat or do-nothing policies because their land has less value than that in towns
  • People may lose their homes and have to relocate in areas where the cost-benefit analysis decides the areas cannot be protected