case studies Flashcards
Holderness coast
- erosion rates of 2m a year
- sea defences in Mappleton (1991) affect the LSD down stream
- geology is boulder clay and chalk (easily eroded)
- strong fetch from the North East+destructive waves
- slumping prone form weathering (mechanical)
Coastal management in Chittagong Bangladesh
and winners and losers
coastal climate resilient infrastructure project
- constructing, improving and extending 25 tropical cyclone shelters.
- training in climate resilience and adaptation.
- raised platforms above expected 2050 sea level
+generated income opportunities for people.
+reduced poverty by 10%
+road flooding only 5 days a year instead of 20
- disturbance of people and natural habitats
- relocation of 200 people by road realignment.
why is Bangladesh especially vulnerable to storm surges created by tropical cyclones?
- much of the country is a low-lying river delta, only 1-3m above sea level
- incoming storm surges meet out-flowing river discharge from the Gnages and Brahaputra rivers, meaning river flooding and coastal flooding combine
- intense rainfall from tropical cyclones contribute to flooding
- much of the coastline consists of unconsolidated delta sediment, which is very susceptible to erosion
- deforestation of coastal mangroves forests has removed vegetation that once stabilised coastal swaps and dissipated wave energy during tropical cyclones.
- the triangular shape of the Bay of Bengal concentrates a cyclone storm surge as it moves north, increasing its height when it makes landfall.
why do rates of erosion vary on the Holderness coast?
- coastal defences at Hornsea, Mappleton and Withernsea have stopped erosion.
- these defences have starved places further south (Easington) of sediment as groins have interrupted LSD
- erosion rate therefor generally decreases from north to south
- some boulder clay are more vulnerable to erosion than others
- some cliffs are more susceptible to mass movement.
isle of Purbeck
-made of clay and limestone so easily eroded
erosional landforms:
-Old harry (cave arch stack stump)
-Lulworth cove
environmental refugees
Kiribati
-low lying land means sea level rise is a risk to many of the islands only a few metres above sealant
Maldives
-the highest point in the country is 2.3m above sea level.
-if sea level rises by the expected 50cm by 2100, we would see 77% of the Maldives disappear into the sea.