Coasts Case studies

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Coasts Case studies
2015-04-14 10:40:28
coasts coast case studies
holderness, towyn, Abbotts farm
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  1. Where is Spurnhead Spit?
  2. Example of a stack and stump
    Old Harry Rocks and his Wife
  3. Name an example of a bar
    Slapton Ley
  4. By how much does the Holderness coastline erode by each year?
  5. How many villages have been been recorded as lost along the Holderness coast?
    29 (including Hartburn)
  6. Why does the Holderness Coastline erode so quickly?
    • Geology (soft rocks made of glacial till)
    • Waves (strong with long fetch)
    • Weather (strong prevailing winds leads to increased LSD and material movement)
    • Human management schemes
  7. What is the geology of the Holderness Coast?
    Glacial Till, a loosely packed soft rock that erodes quickly - especially when saturated, which then leads to slumping or mass movement
  8. Where is the Holderness Coast?
  9. How long is the fetch at Holderness?
    Up to 800km
  10. What is the problem with the sea walls installed on the Holderness coast?
    They are curved, which reflects energy rather than absorbing it, leading to erosion further up the coast.
  11. What is the problem with the groynes installed at Mappleton on the Holderness Coast?
    They interfere with natural sediment movement via longshore drift, which prevents beaches building up behind them, causing cliffs to become liable to erosion
  12. Which towns along the Holderness Coast have had management schemes in place?
    • Mappleton 
    • Hornsea
    • Withernsea
    • Easington
  13. What is outflanking?
    The term given when management schemes cause differential erosion north and south of the defence
  14. What management schemes does Mappleton have? Why? Was it effective?
    Mappleton - rock groynes, cliff regrading, beach renourishment 

    To protect near-by road and community

    regrading wasn't successful as there is slumping, rock groynes are being undermined, less effective
  15. What management schemes does Hornsea have? Why? Was it effective?
    Hornsea - groynes, sea wall, beach renourishment 

    To protect tourist resort

    effective because they were visually pleasing and reduced erosion in area
  16. What management schemes does Withernsea have? Why? Was it effective?
    Withernsea - groynes, sea wall, rip-rap

    To protect tourist resort, reassure residents and protect jobs in area

    effective, it holds the line, residents happy, however sea views have been reduced
  17. What is the approximate cost of management on the Holderness coast?
    over £13 million (just on hard engineering)
  18. What management schemes does Easington have? Why? Was it effective?
    rip-rap, revetments

    to deflect waves away from gas terminal, where 25% of UK gas comes from

    Untested, not sure whether effective or not
  19. How are coastal management decisions made?
    • Cost-benefit analysis
    • Environmental impact assessment 
    • Risk assessment
    • Shoreline management plans
  20. What businesses have been affected by the eroding coastline at Holderness?
    • Tourism, particularly caravan parks
    • Farming
  21. Why is Spurnhead Spit so important?
    • Home to the only permanently manned lifeboat service in area
    • Protects the Humber estuary
  22. What has been the effect of management along Holderness Coast been on Spurnhead spit?
    There is less sediment contributing to the build up of the spit, meaning it is getting eroded and therefore loosing wildlife diversity
  23. What is 'roll back'?
    The act of businesses, such as caravan parks along the Holderness, moving inland in order to continue their business.
  24. What is the Holderness Coast a case study for?
    An area of coastal erosion
  25. What is Towyn a case study for?
    Coastal flooding
  26. What is the case study for a hard engineering coastal management scheme?
    Holderness or Start Bay
  27. What is the case study for a soft engineering coastal management scheme?
    Abbotts Farm, Essex
  28. Coastal squeeze was affecting Abbotts Farm before the installation of coastal management. What is coastal squeeze?
    The result of sea rising over the salt marshes and then being pinned against a sea wall, leading to deeper water, which causes erosion.
  29. What is managed realignment?
    Controlling the movement of the coastline in a sustainable way
  30. How much is the sea level rising along the Essex coastline? Why?
    6mm per year, as a result of global warming and the settling of land mass in the south-east due to isostatic readjustment.
  31. When was the sea wall at Abbotts Farm breached?
    Before the Spring tide in October 2002
  32. Why was the sea wall at Abbotts Farm breached?
    To develop a new saltmarsh, mudflat and coastal grassland as part of a managed realignment strategy
  33. What has the effect of the sea wall breaching at Abbotts Farm been?
    • Reduced pressure on sea walls along estuary
    • Saved £50,000 in sea defences
    • Increased habitats for a range of birds, plants and fish
  34. What disadvantages are associated with managed realignment?
    • Loss of land, and compensation to land owners
    • May disrupt businesses, such as oyster farms as they need clear water and managed realignment can produce silt
  35. What is a ploder? How many are there along the Essex coastline?
    • A tidal area enclosed by wooden fencing which is designed to regulate tidal flow. 
    • There are 26 along the Essex Coastline
  36. What are the benefits of using ploders to create salt marshes along the Essex coast?
    • They reduce soil erosion
    • They encourage deposition of sediment
    • Low cost and sustainable 
    • Decompose naturally
  37. When were the Towyn floods?
    February 1990
  38. What were the physical causes of the Towyn Floods? (5)
    • 1.5m storm surge 
    • Gale force winds
    • high tide
    • low gradient floodplain
    • climate change
    • exposed coast
  39. What were the human causes of the Towyn floods?
    • Highly urbanised coast, settlements built in flood zone
    • unmanaged seawall
    • human impact on global warming - sea level rise
  40. What were the social impacts of the Towyn flood? (3)
    • Some areas of the town had to be evacuated (5000 people)
    • Many people were forced to live in temporary accommodation for up to a year after the event
    • The main railway line was severely damaged by the flooding
    • Affected 2800 properties
    • 6000 caravans damaged
    • No fatalities but the anxiety of the flood is believed to have led to the premature death of about fifty people
  41. What were the economic impacts of the Towyn flood? (3)
    • Electricity, sewage and water pumping systems were all broken= £20 million
    • Summer tourist season ruined, no income that summer 
    • £4.4 million spent on repairs to infrastructure
    • Repairs to the damaged housing stock were believed to have cost between £22.4 million and £100.8 million
    • 50% were entirely uninsured
    • £10.5 million was spent on new coastal defences
  42. What were the environmental impacts of the Towyn flood? (3)
    • Sea water flooded four square miles of low-lying land; effecting 2800 properties
    • The silt left in Towyn after the floods was contaminated with radioactivity 10 times the government safety limits with the pollution likely to have been caused by the nuclear reprocessing plant at Sellafield in Cumbria (The Guardian, 1990)
    • Power to sewage pumping stations was lost which resulted in contaminated flood waters
    • Saltwater contaminated soil
    • Farmland flooded
    • Levees breached
  43. How many homes in the UK are at risk of flooding?
    3.1 million