Coastal Flooding Flashcards
Why is Bangladesh at risk?
The worlds most densely populated country - estimated pop of 169 million in 2015
46% of the country’s pop lives less than 10 metres above sea level
Lies of the floodplain planes of 3 major rivers.
What is meant by subsidence?
Some of Bangladesh’s estuarine islands have sunken by as much as 1.5 metres in the last 50 years.
Isostatic readjustment is partly responsible.
Clearance and drainage of more than 50 large islands in a river delta. These islands used to be forests but have now been cleared.
Human actions to protect them against surges have stop naturals deposition, so the islands are submerging.
What is meant by removing vegetation?
Mangrove forests - one of the most productive and complex ecosystems on the planet.
Are essential for many biodiversity because they stabilise coastlines against erosion, collect nutrients-rich sediment and provide a nursery for coastal fish.
They provide protection and shelter against extreme weather events.
They absorb and disperse tidal surges.
What’s happened to Bangladesh’s mangrove forests?
71% is now retreating by as much at 200metres a year
Caused by erosion, rising sea levels and human actions
What were the impacts in Bangladesh?
Severe flooding in low lying areas Damage to infrastructure Electricity and communication affected Water was contaminated Lack of sanitation = high risk of disease
4234 dead and missing
55,282 injured
Nearly 2 million animals died
Cost - $29.6 million
What increases food risk?
Subsidence
Removing vegetation
What are storm surges?
Changes in sea level caused buy intense low-pressure systems - depressions and tropical cyclones - and high wind speeds.
How can climate change increase flood risk?
Warmer ocean surfaces and higher sea levels = more intense, regular storms.
How can adaptation be used to reduce flood risk?
Building sea walls
Building storm surge barriers
Reinstating mangrove forests
How can mitigation be used to reduce flood risk?
Efforts to reduce emissions
What are the impacts of the 2013 storm surge in the UK?
Strong winds
Coastal flooding (1400 homes) and forced evacuation
Several properties collapsed into the sea
Bridges were shut
Rail services were disrupted
2 people died
Thames barrier was closed to protect London.
Damage at £100 million
