Case study: Flooding in bangladesh

Question 0

Physical causes

Answer 0

• 3 major rivers flow through Bangladesh : The Ganges, The Brahmaputra and the Meghna.
• 70% of Bangladesh is less than 1m above sea level –> low lying.
• Snow melts in Himalayas increases river discharges.
• Regular cyclones casuing storm surges.
• 10% of Bangladesh is covered in lakes and rivers.

Question 1

Human causes

Answer 1

• Deforestation –> decreases interception by plants, increases surface run-off
• Urbanisation –> decreases infiltration and also leads to the growth of informal settlements on floodplains.
• Poorly mainted flood defences.
• Dams in India causing sedimentation of rivers.
• Global warming –> snow melts in Himalyas, increases sea levels as well as the frequency and magnitude of cyclones.

Question 2

Effects of the 1998 Flood

Answer 2

• 57% of Bangladesh was flooded
• Over 1300 people killed
• 7m homes destroyed, making 25m homeless.
• Spread of water-borne diseases like Typhoid.
• Shortage of clean water and food (2m tonnes of rice were lost).
• 500k cattles killed.
• Raliways, roads, bridges swept away.
• Total cost: >1 billion USD.

Question 3

Short term Management in Bangladesh

Answer 3

• Humanitarian aid: + Boats to rescue victims.
  + Emergency water + food supplies.
  + International aids.
  + Tents and blankets

Question 4

Long term solutions

Answer 4

• Reduce rate of Deforestation in Himalyan foothills
• Building seven large dams - $40m, 5000 flood shelters, 350km levees.
• Flood water storage.
• Deevelop flood warning scheme.