Coasts Case Studies Flashcards
Holderness Coast:
- Fastest eroding coastline at 2m per year (UK), some areas up to 10m per year
- Mostly made up of chalk and soft boulder clay, erodes rapidly when saturated
- Eroding also due to fetch, prevailing winds and LSD moving material South
- Narrow beaches due to limited sediment supply from rapid erosion
Kiribati First Climate change refugees:
- 1.2cm sea level rise per year
- Have bought land in Fiji and agree with neighboring countries to allow migration, population of just over 120,000
- Water insecurity
- Mangroves have been planted to limit erosion
Jakarta, Indonesia:
- Indonesian capital is sinking, 32 million people
- Sea level rise as a result of climate change
- People are illegally draining underground aquifers because they don’t have access to water
- As a result ground is sinking 25cm per year, 2050 its gone
- 32km sea wall has ben built but its not enough
New York:
- Tidal flooding has increased by 247% since 2000
- Increased flooding, infrastructure damage, and threats to low-lying areas like Manhattan and Staten Island.
- urbanisation leads Increases runoff, reduces natural barriers, and contributes to habitat loss for marine ecosystems.
Nile Delta:
- Agricultural, urban and industrial sectors are extracting groundwater at exponential rate
- Aswan high dam has reduced the amount of sediment reaching the delta up to 98%
- Increasingly also due to natural gas extraction
- Home to around 41% of Egypt population
Bangladesh:
- Subsidence over 1.5m over the last 50 years
- Deforestation to grow rice
- About 30 million live on polders
- All have prevented the natural distribution of sediment
- Lies on the floodplain of 3 major rivers
- Himalayan snow melt and monsoon season adds to flood risk
Storm Surges, UK
- Storms driven by powerful jet streams bringing depressions across the Atlantic
- 18,000 people evacuated
- 800,000 properties protected by the environment agency flood defences
- 720 properties were flooded
- Estimated cost was £200 million
- In response gov invested £270 million
Storm Surge, Hurricane Sandy
- Wind damage up to 100mph
- 286 total deaths
- One of the costliest hurricanes $60 billion
- 346,000 homes damaged
- +18,000 flights cancelled
Mappleton, Holderness Coast
- Supplies 25% of UK gas
- Area is starved of material and eroding at excessive rates
- 2 groynes and rock armour helps protect the cliff but makes cliffs further down south worse
- £2 million
Cyclone Sidr - Bangladesh
- 223km/hr
- Storm Surge up to 6m
- Breached coastal and low lying areas
- Extensive flooding
- $1.7 bn in damages
- Water contaminated by debris
Fairbourne
- Low lying land, sea level rise
- Residents have to be relocated
- At risk for more violent storms
- Will use hold the line then managed retreat
Bacton, North Norfolk
- 1.8 million metres cubed of sand has been placed to replenish beach (sandscaping)
- Protects gas terminal and village
- £20 million
- Beach needs to be replaced every 15 - 20 years
Borth, Wales : Management Stategies
Hard Engineering
- Rock Groynes, installed to reduce longshore drift
- Breakwaters, Rock structures designed to absorb wave energy
- Rock Armour, Placed along the shore to protect the coastline from wave attack
Soft Engineering
- Beach nourishment, Sand + gravel replenish the beach and increase its size
- Dune Stablisation, planting vegetation to satablise dunes
Borth, Wales: Effectiveness of management strategies
Successes
- Economic Benefits, Protects 400 homes and local businesses
- Tourism, enhanced beach attracts visitors
- Environmental protection, maintains wildlife
Challenges
- Cost, high inital and maintenance cost for hard engineering measures
- Sediment disruption, rock groynes interrupt natural sediment transport
