G1 - Question 2 - Rivers and Tectonics - Hydrology (at some time)

Question 1

Bangladesh

Name the 7 factors influencing flooding in Bangladesh

Answer 1

1. Low lying floodplain. 80% of the country is located on the delta and only 1m above sea level
2. Monsoon climate - brings heavy rain and snowfall
3. Spring snow melt - adds to water input, increases soil erosion and rapid increase in river discharge
4. Siltation of the rivers
5. Diversion for **forced irrigation **
6. Cyclones in the Bay of Bengal
7. Deforestation in headwater areas

Question 2

Bangladesh

What is the Bangladesh Flood Action Plan?

Answer 2

Introduced in 2004, the flood action plan introduced set back embankments which would protect them from erosion but prevent 1:10 year floods, not catastrophic floods such as in 1988

Question 3

Bangladesh

What were the criticisms of the flood action plan?

Answer 3

• Reduces back flow
• Creates longer periods of inundation
• Failure would be catastrophic
• Stops cyanobacteria flooding fields - farmers will need fertilisers they cannot afford
• Dry season water reduction - water stress
• Pollutants would enter due to reduced flushing effect from compartmentalisation

Question 4

Shrewsbury floods

When was it and what caused it?

Answer 4

October 1998

October experienced 135mm rainfall, 20% of yearly average - increased discharge +made flashy due to urbanisation of the floodplain, saturated soils and steep-sided topography

Question 5

Shrewsbury Floods

What were the social impacts?

Answer 5

No reported loss of life

Major illness averted due to Environmental Agency warnings

Loss of property - 400 residential and commercial

Physcological impacts

Reduced transport and access - Welsh bridge damaged

Question 6

Shrewsbury Floods

How was Shrewsbury effectively managed?