Rivers, Floods and Management - Bangladesh Case Study Flashcards Preview

AS Geography > Rivers, Floods and Management - Bangladesh Case Study > Flashcards

Flashcards in Rivers, Floods and Management - Bangladesh Case Study Deck (55)
Loading flashcards...
1
Q

Location

A

South-Central Asia

2
Q

Frequency of major floods

A

Every 8 years

3
Q

3 major rivers

A

Meghna
Brahmaputra
Ganges

4
Q

Capital of Bangladesh

A

Dhaka

5
Q

Population of Bangladesh’s capital

A

Dhaka 1 million

6
Q

How much rainfall fell in Bangladesh and when? This was the worst rain for how many years?

A

350mm in 24 hours
13th September 2004.
Worst rain for 50 years.

7
Q

How much of Bangladesh is how far above sea level? Why?

A

20% less than 1 metre above sea level.

Because it is built on a floodplain on delta land.

8
Q

Summary: 5 physical causes of Bangladesh flood

A
  • Heavy rainfall
  • Monsoon climate
  • Low lying
  • Himalayas
  • 3 major rivers
9
Q

What system was put in place for farming? Which river? Effects?

A

Irrigation system to divert the Ganges.

Reduced speed of flow in channels = more deposition inland, less on low lying delta = didn’t build up

10
Q

Name 2 places where urban growth occurred

A

Nepal and Tibet

11
Q

Summary: 4 human causes of flood

A
  • Irrigation diverted Ganges
  • Urbanisation
  • Deforestation of Himalayas
  • Global warming
12
Q

Deaths

A

800

13
Q

How much of the country was flooded?

A

38%

14
Q

How much of Dhaka was under water and in which month?

A

40% under water in July

15
Q

How many bridges destroyed?

A

900

16
Q

How much road damaged?

A

15,000 km

17
Q

How much farmland destroyed?

A

800,000 ha

18
Q

How many people suffered from diarrhoea in Dhaka?

A

100,000

19
Q

Cost of total damage?

A

$7 billion

20
Q

2 other long term impacts

A

Rice crops devastated = food shortages

Jute and sugar cash crops rotted = money shortages

21
Q

How much aid did the UK give?

A

£21 million

22
Q

How much aid did the UN appeal for? How much did they actually get?

A

Appealed for $74 million.

Only got 20% by September

23
Q

What charity gave Bangladesh short term aid?

A

Water aid - water purification tablets

24
Q

2 other short term responses

A
  • NGOs: rice, clothing, medicine, blankets

- Farmers given free seed

25
Q

9 long term responses

A
  • Flood action plan formed
  • Early warning system
  • sluice gates
  • 2 ha of raised land for flood shelter
  • Coastal homes on stilts
  • homes raised by 2m on earth banks
  • Embankments strengthened
  • Self help schemes: rebuilt homes & communities
  • Additional financial aid granted
26
Q

By how much were homes raised on earth banks?

A

2m

27
Q

How much raised land was created for flood shelter?

A

2 ha

28
Q

Date

A

2004

July—> September

29
Q

What economic factor limits Bangladesh’s ability to manage floods?

A

GDP per capita = $700 and tax revenue limited = rely on foreign aid and NGOs

30
Q

Why did heavy rainfall lead to flooding?

A

Groundwater stores filled = water table reached surface = surface runoff

31
Q

When is the wet season?

A

May to September

32
Q

What causes rain to coastal regions? How did this lead to floods?

A

Low pressure and winds fro southeast = heavy rain

Meghan reached peak level in July

33
Q

What brings intense precipitation and storm surges?

A

Cyclones from Bay of Bengal

34
Q

What area of Bangladesh is easily washed away by floodwater and why?

A

Densely populated island - Chars

Made up of mud deposits = unstable

35
Q

How did Himalayas lead to flooding? 3 ways

A
  1. Snow and glacial melt increase discharge of Ganges and Brahmaputra
  2. Tectonic uplift = rivers have more GPE = more erosion = sediment deposited downstream which chokes channels
  3. Relief rainfall - high slopes = faster and more runoff
36
Q

Which glacier in himalayas contributed to flooding and how?

A

Gangotri Glacier in Indian Himalayas feeds ganges. Melts at 25m per year.

37
Q

what type of causes have become more important in recent decades?

A

Human causes of flooding

38
Q

Where did deforestation occur and why?

A

In Himalayas due to pop pressure in Nepal and Tibet - need more grazing land and wood for fuel

39
Q

How did deforestation contribute to flooding?

A

Less interception and evapotranspiration = more runoff

Soil erosion = river bed aggradation = reduced capacity

40
Q

How did urbanisation contribute to flooding?

A

Impermeable surfaces = more runoff and less infiltration = discharge increased, lag time decreased.
Increased magnitude and frequency of flooding.

41
Q

How did global warming contribute to flooding?

A
  • More extreme weather = increased quantity and intensity of monsoon rain
  • Higher temp = more snow melt
42
Q

By how much is rainfall estimated to increase due to global warming and by when?

A

10-15% increase by 2030

43
Q

How much rice was destroyed?

A

2 million tonnes

44
Q

Who lost their livelihoods?

A

Subsistence farmers

45
Q

What infrastructure was damaged?

A

Railways, roads, embankments, irrigation system

46
Q

What groups of people were most affected?

A

Poor farmers, landless labourers and slum dwellers

47
Q

How many people homeless?

A

36 million (25% population)

48
Q

How much untreated sewage escaped into water each day?

A

500,000 cubic meters

49
Q

5 environmental impacts of flooding

A
  1. Land flooded
  2. River bank erosion on embankments near main channels
  3. Soil erosion
  4. Waterlogged urban areas
  5. Water Contamination
50
Q

Describe early warning system put in place

A
  • Satellite monitoring linked to local radio stations to send warnings
  • warnings from loudspeakers in Mosques
51
Q

Who and for how long was financial aid granted?

A

5 year period

- World bank loan to paid for infrastructure repairs, water resources management and education

52
Q

What dates did Bangladesh have catastrophic flooding again?

A

2007 and 2010

53
Q

Why is Bangladesh under greater threat?

A

Sea level rise and more storm surges

Climate change made cyclones more powerful = higher storm surges

54
Q

How much is temp supposed to rise Bay of Bengal?

A

2- 4 degrees next 40 years

55
Q

What rise in sea level would be catastrophic and why?

A

50-100 cm rise = 20% country flooded = 15 M refugees