Flashcards in case studies Deck (6)
-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
-Old harry (cave arch stack stump)