Bangladesh Flashcards
Storm surges
40% of all recorded storm surges happen in Bangladesh
Most at risk from tropical cyclone storm surges
Height
Low lying river delta (<9m)
Majority is <3m above SL
Sediment
Coastline is unconsolidated delta sediment
Dynamic + more erosion
Rivers
Ganges + Brahmaputra
3rd largest discharge (30770m3/s) + largest suspended sediment load (1.84bil tonnes/yr)
Mangroves
Deforested mangroves
Stabilised swamps + dissipated wave energy
Coastal shape
Triangular shape acts as funnel
Intense cyclone rainfall - more flooding — leads to disease (cholera/malaria)
Tropical cyclones
Creates LP - less weight of air so SLR (storm surge)
Wind speed reaches 260kmh - high energy waves (more height)
SLR
28-98cm SLR within the century - 65cm by 2080
40% farmland lost
Subsidence
Bengal Delta subsiding 8-18mm/yr (isostatic readjustment)
Himalayas uplifting + compaction of buried sediment + humans (urbanisation + dredging)
Cyclone Sidr, 2007
3m storm surge + 260kmh winds
15000 deaths + US$1.7bil damage + 3mil houses lost + 2mil lost income source
Hypothetical
If 40cm SLR - 11% of Bangladesh’s coastal land submerged - 7-10mil refugees