Case Study 1 – Bangladesh flooding 2007
Floods most years due to:
- Monsoon Climate – 80% of rain falls in 4 months of the year
- Low Lying – 90% of Bangladesh is less than 10m above sea level.
- Melting snow and ice from the Himalayas in late summer months. Leads to higher discharge in the Brahmaputra river.
In July and August 2007 flooding in Bangladesh was severe.
Main Causes (Physical):
- Very dry and early summer meaning monsoon hit was sudden.
- Long duration of rainfall meant that the soil was fully saturated, leading to a rise in surface runoff.
- The heavy rainfall was intensified by a storm from the Bay of Bengal on June 9-10, 2007
- Peak Discharge in the River Ganges and Brahmaputra, increased river discharge downstream.
- Deforestation in Nepal and the Himalayas leading to less interception.
- Urbanisation leading to increased surface runoff.
- Collapse of old earth dams in India caused further flooding.
- over 2000 deaths due to reluctance to evacuate and poor transport infrastructure
- over 100,000 people caught water-borne diseases due to pollution of wells
- 25 million made homeless
- 4000 schools affected
- Cost $1 bn
- Factories closed leading to poorest workers becoming unemployed
- 80% of population rely on agriculture so many lost livelihoods.
- 550,000 hectares of land couldn’t be planted with rice
- 10,000 km of roads destroyed
- Household and Government debt increased
- Fertile Silt deposited on floodplains
- River polluted with sewage
Impacts worse due to:
- Less developed – couldn’t afford all defences possible
- Low incomes / savings meant recovery inhibited by lack of money
- Corrupt officials diverted aid money to less in need areas