1.2 Case studies Flashcards
Location of Hemsby
Hemsby is a village, seaside resort and civil parish in the county of Norfolk, England
Issues in Hemsby
- homes falling into the sea due to cliff erosion of very soft clay + sand in storms
- no sea defences - public funding refused, Hemsby not considered economically valuable enough
How have people in Hemsby responded?
- people are fundraising for sea defences
- helping people clear + evacuate coastal homes in storms
Impacts of erosion in Hemsby
- potential loss of the cultural history/identity of the town
- area is reliant on tourism, with many businesses by the sea
How has beach nourishment been used in Norfolk?
- in 2019, 2million m3 of sand was placed on the Norfolk coastline near Bacton
- aimed to prevent flooding of homes and businesses and protect Bacton gas terminal
- cost £20m - biggest contribution from Bacton Gas Terminal
Has the Norfolk beach nourishment been successful?
2 years on
- heavy storms caused waves to crash into sand and create a 2m drop
- sand has moved further down the beach, creating a sand bar that breaks waves’ energy
- has prevented flooding in gas terminal and nearby villages
Issues facing sand dunes in Berrow, Somerset
- sea buck thorn is an invasive species that outcompetes marram and needs to be removed manually
- trampling kills vegetation, causing blowouts in storms
- paths, roads, and walkways create weaknesses in dunes, which cause wind tunnels and flooding
Dune management in Berrow
- soft management: rerouting paths, boardwalks, porous collection, fencing
Dune management in Ynyslas, Wales
- management focused on educating public
- wooden paths
- free access to some areas, no access to others
- information centre
- warden
- allow school fieldwork to take place in some areas
Location of Keyhaven Marshes
-Hampshire
-Behind Hurst Castle Spit
- Western Solent
Describe the formation of Keyhaven Salt marshes
- developed due to formation and migration of Hurst spit
- spit is maintained by supply of shingle from west and longshore drift
- spit provides sheltered environment for mud flats and marshes to form
- spartina has led to marshes growing 2m higher than usual
why is the hurst spit receding?
- groynes and engineering works to the west
- increased storms
impacts of the recession of the hurst spit
- rapid erosion
- reduced height of spit
- breaches in the spit
- if not dealt with, the spit might’ve become isolated and marshes overwhelmed by marine attack
Impacts of declining spartina on Keyhaven salt mashes
- exposed slumping platforms of bare mud - vulnerable to erosion
- this would expose coast to wave attack, flooding habitats
Describe the Shoreline Management Plan used at Keyhaven Salt marshes
- marshes and hurst spit not totally independent so holistic approach needed
- 550m of rock armour protecting Western end at milford
- spit nourished with 300,000m3 of shingle
- 100m rock revetment at Eastern end to protect tip
Long-term management strategies for the Keyhaven saltmarshes
- existing defences on landward side of spit maintained
- more information needed about saltmarshes
- working party should be established to investigate and develop strategies
- detailed assessment of marshes to be carried out
Location of Kiribati
33 islands in the Pacific Ocean
Why is Kiribati at risk of sea level rise?
- very low-lying sand and mangrove islands (1m above sea level)
- sea levels rising 4x faster than global average
Impacts of sea level rise in Kiribati
- 2 islands completely flooded
- contaminated groundwater
- coral bleaching caused by warming oceans
- loss of outer islands and erosion of beaches means it is more at risk from storms
- food scarcity - increased storm surges killed crops and contaminated water
- increased temperature and water contamination spreads diseases
Responses to rising sea levels in Kiribati
- in 2014 President Tong purchased land in Fiji for agriculture or future migration
- ‘migration with dignity’ policy allows people to apply to jobs in neighbouring countries
- new President Maamau plans to dredge underneath islands then raise them higher above sea level
- people built walls out of coral, mangroves planted, towns moved inland
Barton on sea - Location and geology
- Christchurch Bay is a subcell of the Dorset-Hampshire littoral cell
- unresistant geology, high energy processes mean that coastal recession is avg 1m/year
How is west barton on sea being managed?
- West to Naish farm and highcliff has a retreating and collapsing cliff
- managed retreat
- mobile caravans relocated
- soft engineering will allow for some cliff erosion while keeping the beach front in pleace
How is central barton on sea being managed?
- holding the line
- no new developments on cliff edge
- new or redeveloped properties up to 400m inland must have soakaways to reduce groundwater build up
- risk of property loss
- hard engineering: revetments, rock armour, groynes, cliff regrading, beach nourishment
How is East barton on sea managed?
- part of SSSI with major retreats in the cliffs
- do nothing approach
- re-routing of coastal foot path
- only losses to golf course
What are the problems in Happisburgh, Norfolk?
- failed to qualify for coastal defences
- homes lost to sea
- by 2015, shoreline may recede by 200m, losing 50 homes, property losses of £50m
- loss of life boat and beach access ramp in 2003 affected tourism
- house values are low and people cannot afford to move elsewhere
What are the suggested solutions in Happisburgh?
- do nothing approach
- no national system of compensation
- in 2009, government provided £5000 for demolition and £1000 for relocation
- £1.4 million was set aside by community for ‘purchase and lease-back’ of 11 houses
- pathfinder project
Describe the pathfinder project
- owners offered half of ‘non-blighted’ house value
- Beach road houses demolished and a buffer between cliff and village established
- grants to relocate manor farm caravan park, public toilets, and derelict coastal defences
- planning rights for coastal properties sold to local council
- funded purchase of landward farmland to replace homes
Views of the CCAG
- coastal concern action group
- raise awareness of erosion issues
- lobbied for policy change to allow for coastal defences in the future
Why is Bangladesh prone to coastal flooding? - environmental reasons
- coriolis effect leads to storms moving from equator northwards - amplified by bay of bengal
- low-lying country
- river deltas for major rivers (Ganges, Meghna, Brahanaputra)
- monsoon season often at same time as cyclone season
- climate change causing sea level rise and himilayan ice to melt
- land made from deposits of silt so easily eroded
Why is Bangladesh prone to coastal flooding? - economic reasons
- LIC: lacks funds for coastal protection to mitigate against flooding
- poorly built property more likely to collapse
Why is Bangladesh prone to coastal flooding? - social reasons
- high population density
- population rising rapidly
- people living in vulnerable areas
What problems does Bangladesh face as a result of sea level rise?
- 100,000 people displaced every year by erosion
- salt water pollutes farms and freshwater sources
How are Bangladesh adapting to the threat of coastal flooding?
- aquaculture: raising crabs in the salt water brought by storm surges to sell
- fresh water provided by NGOs - fresh water taps and desalination plants
- agriculture: farmers dug holes in sand and plant pumpkins to sell throughout the year, changing for chickens to ducks as they can handle damp conditions
Netherlands - describe the Deltawerken project
- Hard engineering project which began following the 1953 Storm Surge drastically damaged the Netherlands.
- 1800 people died during the storm surge as well as the flooding of 10% of the Netherlands’ farmland.
- Consists of a series of dams and gates constructed along rivers to control the flow of water during a storm surge.
- It also aims to reduce the length of the coastline exposed to the sea whilst maintaining safe access to the North Sea for shipping.
Netherlands - benefits of the Deltawerken project
- It has allowed for 4 million people to live below normal sea level, hence easing the Netherlands’ population growth.
- The dams have allowed for new roads and transport connections, which drastically reduce journey times and reduce isolation for settlements.
Netherlands - costs of the Deltawerken project
- Cost $5 billion. However, due to sea level rise, the Dutch will need to spend more than $1 billion annually to maintain and improve defences against the rising sea levels.
- A number of nature reserves were lost during construction, though some have been replaced during the project.
