case studies

Question 1

Coastal management in Chittagong Bangladesh

and winners and losers

Answer 1

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.

Question 2

why is Bangladesh especially vulnerable to storm surges created by tropical cyclones?

Answer 2

• 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.

Question 3

why do rates of erosion vary on the Holderness coast?

Answer 3

• 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.

Question 4

isle of Purbeck

Answer 4

-made of clay and limestone so easily eroded
erosional landforms:
-Old harry (cave arch stack stump)
-Lulworth cove

Question 5

environmental refugees

Answer 5

Kiribati

low lying land means sea level rise is a risk to many of the islands only a few metres above sealant

Question 6

Holderness coast

Answer 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)