Rivers of Bangladesh

Question 1

What are the three main rivers in Bangladesh?

Answer 1

Meghna, Ganges, Brahmaputra

Question 2

What has caused the rivers to flood?

Answer 2

1. Monsoon tidal waves- Monsoon storms could create huge tidal waves which will flood the land along the southern coast of Bangladesh.
2. Deforestation- Deforestation for firewood, furniture and sports equipment means less interception of rainfall. More become surface flow.
3. Overflow- Sediments are deposited along the riverbed. This causes the rivers to become more shallow and less able to hold water.
4. Channel straightening- Concrete embankments and channel straightening increases discharge rate of rivers and thus causes more flooding downstream. Prevents natural drainage.

Question 3

What are the benefits of flooding?

Answer 3

1. Makes land fore fertile due to silt in floodwater.
2. Can flush out disease.
3. Provides irrigation to crops.

Question 4

What are the disadvantages of flooding?

Answer 4

1. Destruction to homes.
2. Causes death of fish population, which makes up 80% of people’s protein diet.
3. Kills thousands of people, destroys buildings, industry, crops, communication…

Question 5

What are some flood protection methods?

Answer 5

1. River straightening- Increases the discharge rate of rivers. Carries water away faster and thus reduces risk of flooding.
2. Levees- Concrete or dirt barriers that hold back water. Prevents immediate flooding but failure can increase damage of flooding.
3. Dams- Increase control of river and holds back water. Reduces irrigation to farmers downstream.
4. Tidal barriers- Protects against tidal waves and restricts drainage of rivers. Holds back nutritious silt, helps crops. Holds back chemicals and pesticides.
5. Urban flood protection- Levees and embankments protect urban areas, reducing sewage breakage, communication blackouts and spread of disease.

Question 6

How can people live with floods?

Answer 6

1. Killas are houses on stilts. They can be cheaply built and can hold up to 5000 people per killa. Can be used in urban and rural areas.
2. Embankments- Improves discharge but costs money and needs rocks which have to be imported. (£20 million per km).
3. Flood warning technology- Increases co- operation with countries like India to make advancements in IT skills.