Rivers Of Bangladesh

Question 0

How and why does the river flood?(4)

Answer 0

Monsoon and snow melt- huge tidal waves and constant rain combined with snow melt from the Himalayas can cause serious flooding.

Deforestation- means less interception and more surface runoff

Overflow- rivers carry 1600 tonnes of silt + block rivers

Channel straightening- and concreted sections can increase speed of river.

Question 1

Give some background information.

Answer 1

• The drainage basin is extensive, covering much of Bangladesh. The Himalayas form the watershed.
• The flood plain covers 50% of Bangladesh’s land area.

Question 2

What are the pros and cons of flooding?(6)

Answer 2

Pros: Cons:
- Bring silt fertiliser - kill humans,animals and
- wash out salt from delta. crops.
- flush out disease. - destroy housing and
buildings.
- carry sewage.
- kill fish, people rely on.

Question 3

What schemes are being used to prevent flooding?(4)

Answer 3

• River straightening/levees - Raise banks but increase spread of water.
• Dams- hold back water but reduces useful irrigation and stops useful silt.
• Tidal barrage across Bay of Bengal - very expensive but would protect poorest land and people, they would make crops more reliable but could cause build up of chemicals.
• Urban flood protection levees- would benefit rock more than poor but could reduce problems of sewage and chemicals flowing downstream.

Question 4

Name strategies to save life’s.

Answer 4

Killas- are concrete shelters on stilts, can protect up to a thousand people and animals. They are good because they are cheap, easy to build and help both the poor and rich.

Embankments - strengthens river banks but they are expensive and prevent fishing.

Satellite warning system

Urban flood protection- protects most populated and costly areas. Not for poor/rural.

Question 5

Case study of:

Answer 5

Water - hydrology case study

Question 6

Name of river

Answer 6

Brahmaputra

Question 7

What is it a confluence of

Answer 7

Megha, Ganges and Bralmaputa