Geography Unit 1 Case Studies

Geography AQA ASLevel case studies for rivers, coasts, population and Health issues.

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  • Created by: Ellen
  • Created on: 14-05-11 14:09

Causes and Impacts of flooding: South Asia 2007

South Asia floods most years because of:

  • Monsoon climate - 80% of rain fell in 4 months
  • Low lying land ( Bangladesh- 90% of land is less than 10m above sea level
  • Melting snow and ice for the Himalay's.

The flooding was particularly severe in Bangladesh and India.

Physical Factors:

  • Monsoon cam suddenly after very early, dry summer.
  • heavy rain for a long duration
  • saturated soil -> no infiltration -> increased surface runoff and discharge
  • Peak discharges of Ganges and Brahmaputra coincided ->increased discharge downstream

Human Activites:

  • Deforestation in Nepal and Himalays -> less rainfall intercepted -> increased discharge
  • Growth of urban areas -> surface runoff
  • collapse of old earth dams -> further flooding.

Social Impacts

  • over 2000 died
  • lack of clean drinking water -> over 100000 people caught water bourne diseases
  • 25 million homeless
  • 112000 houses destroyed in India
  • Dhaka inundated
  • 4000 schools affected -> loss of education
  • 44 schools totally destroyed.

Economic impacts:

  • cost: US$ 1 billion
  • factories closed
  • loss of livestock ( 80% of Bangladesh rely on agriculture)
  • 550000 hectares of flooded fields
  • 1000km of roads destroyed
  • debt increased

Environmental factors:

  • rivers polluted with sewage
  • fertile silt on flood plain

Human Factors:

  • No flood defences or flood warnings in place
  • little insurance
  • corrupt officials
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Carlisle, Cumbria, 2005

River Eden runs through North Cumbria and reaches the sea near Carlisle

Large Drainage basin -> higher discharge
Steep Sided Basin -> runs quickly down the river
Streams drain into river -> short lag time

Physical factors:

  • heavy rainfall
  • saturated ground -> less infiltration -> increased surface runoff
  • High peak discharge

Human Factors:

  • large built up areas
  • little infiltration
  • drains and sewerage systems overflowed

Social Impacts:

  • 3 people died
  • 3000 made homeless for up to a year
  • personal possesions damaged
  • temporary accomadation disrupted lives
  • 4 schools severly flooded -> lost out on education
  • increase in stress related diseases

Economic activities:

  • repairs cost over £100million
  • 350 businesses shut
  • united biscuits flooded with 3m of water ->£5 million damage -> 33 people lost jobs
  • 70000 addresses had no power
  • 80 buses destroyed

Environmental impacts:

  • Increased river bank erosion
  • polluted rivers.
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Hard Engineering on the River Yangtze, China

Yangtze River flows through China, 6380km long and is the 3rd longest river in the world.

Seasonal flooding is common.
Rainy season June - August
Often causes flooding -> huge discharge

5 major floods - 1931, 1935, 1949, 1954, 1998

1954 - covered 193000km2 of land. 
           Killed 33169. 
          18 million had to move. 
          covered Wuhan city over 3 months

1998 - killed 3000
           14million made homeless.

Flood protection - Hard engineering - mainly dams and levees

Three Gorges Dam:

  • 101m high
  • 1994
  • reservoir catches flood water - can store 22km3 of water
  • hydroelectris power station - 26 turbines
  • locks so ships can pass


  • 3600km of levees along middle and lower parts of river.

Positive effects:

  • reduced major flooding from once every 10 years to once every 100
  • turbines produce enough energy to supply 3% of China's demand
  • safer to navigate the Yantze
  • River shipping increased - reservoir deeper

Negative effects:

  • people had to relocate as water level ion reservoir rose (between 1.3 and 2 million will have to relocate. 13 cities and 1352 villages will be submerged)
  • flood farmland
  • 657 factories flooded
  • 1300 sites of cultural and historical interest flooded - Temple of Zhang Fei
  • dams trap sediment -> failure
  • destroys habitats
  • endangers species
  • increase flooding along tributaries

Levees - negative effects:

  • 1998 floods broke levees -> devastating floods
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Soft Engineering in Abingdon, England

Abingdon, South East England. Built on flood plains of the River Thames and Ock.

1500 properties have a 1% chance of flooding in a given year.

regular floods - 1947, 1968, 1977, 1979, 1992, 2000, 2007

Intense storms in July 2007 -> bad flash floods
River Thames and Ock burst their banks -> flooding 660 properties
Incresed surface run off -> flooding worse

Hard engineering was rejected- too expensive and increased flood risk downstream.


  • gravel soakways built
  • low value land allowed to flood
  • planning restrictions - must have improves drainage systems
  • tesco forced to add drainage improvements eg soakways and permeable tarmac
  • environmental agency warns specific areas at risk - local flood warning plan
  • restrictions on land use
  • detailed advice on reducing flood damage
  • flood warnings communicate advice and warnings
  • planting trees.
  • Difficult to measure success
  • flooding still happens in Abingdon.
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Coastal erosion - Holderness

Holderness- East Yorkshire
Fastest eroding coastline in Europe
Average rate of erosion - 1.8m per year
Holderness coastline 61km long.


  • cliffs made of boulder clay which is easily eroded through corrosion
  • prone to slumping when boulder clay is wet
  • narrow beaches
    • Flamborough Head stops sediment from North replenishing beaches
    • Made of chalk which dissolves rather than making sand
    • coastal defences - human cause
  • powerful waves
    • long fetch from Artic ocean
    • coast faces the dominant wind and wave direction - NE

Social Impacts:

  • Property prices fallen
  • 30 villages since roman times lost

Economic impacts:

  • visiter numbers in Bridlington Dropped by over 30% between 98 and 06
  • caravan parks at risk - seaside caravan park at Ulrome losing 10 pitches a year
  • £2million spent at Mappleton in 1991 to protect coast
  • Gas terminal at Easington is at risk (25% of Britains gas supply)
  • 80000m2 of farmland lost each year

Environmental impacts:

  • SSSIs threatened - the Lagoons near Easington
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Coastal Flooding

Can be caused by:

  • Storm Surges ( storm surge of 1953)
  • Tropical Cyclones (Hurrican Katrina 2005)
  • Tsunamis (south Asia, 26.12.04)
  • Global Warming

If Global Temperatures continue to rise and land ice melts, global sea levels will rise

Warmer sea temperatures also cause sea level rise - warm water expands

Low lying areas are at risk from flooding - Bangladesh and Maldives

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Coastal flooding - The Storm Surge of 1953

STORM SURGE -  a rise in sea level associated with very low pressure systems and high wind.

3 contributing factors to coastal flooding:

  • height of land above sea level
  • tidal range
  • incidence of storm surges

These factors all played an important role in the Storm Surge of February 1953

WHAT: Storm surge
WHEN: February 1953
WHERE: North Sea towards East Anglia, Briatin and The Netherlands (lowlying land)

Low pressure air allowed the sea to rise overall by 0.5m and strong winds generated waves over 6m high

was happening during the spring high tides - all the rivers were already discharging into the North Sea at flood levels

Tides reached 2-3m above normal in EAST ANGLIA, THE THAMES ESTUARY and THE NETHERLANDS - lead to widespread flooding

260 died in ENGLAND

1835 died in the NETHERLANDS

Human causes:

  • Netherlands has a long History of reclaiming land from the sea
  • drained large parts of marshland in East Anglia for farmland - encouraged population spread
  • coastal defence schemes of 1953 were inadequate

Thames Barrier was Built in 1982 to help stop river flooding in London

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Coastal Flooding - Hurricane Katrina

WHAT: A Hurricane
WHEN: 2005
WHERE: New Orleans, USA - Mississippi delta

Low lying land - High population density

51% of New Orleans is at or below sea level

City protected from the sea by artificially heightened levees

winds of well over 100km per hour were recorded

coast experienced a storm surge greater than historical maximums

storm surge of up to 10m, wave action and high winds resulted in widespread destruction

failure of eastern levees and flood walls left parts of New Orleans under 6m of water - inadequate

estimated over 1800 lives lost

property damage between $60 billion and $125billion

loss of wetlands

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Coastal Flooding - South Asia Tsunami

WHAT: a tsunami
WHEN: 26.12.04
WHERE: Southern Asia - Indonesia, Sri Lanka, Thailand and India

Caused by a submarine earthquake in the Indian Ocean

Earthquake reached 9.0 on the Richter Scale - making it one of the strongest earthquakes ever recorded

  • tsunami travelled across the Bay of Bengal at speeds of 800km per hour - waves struck South Eastern India 2 hours after the earthquake
  • Reached more than 2km inland in North East SriLanka
  • waves up to 30m high struck the Indonesian Island of Sumatra (epicente) withing minutes of the earthquake

Deadliest Tsunami ever recorded

230000 people killed or missing

1.7 million people made homeless

drinking water polluted by saltwater and sewage

400000lost jobs in SriLanka

cost of initial damage between $8billion and $15 billion

Boats, nets and fishing equipment destroyed and lost

Salinisation (increased salt) of land reduced fertility

Tourism went down

8 million litres of oil released into environment

salt content of water destroyed ecosystems

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Coastal Management - hard engineering

  • Holnerness Coastline

11.4km of the 61km coastline is protected by hard engineering

  • Bridlington is protected by a 4.7 m sea wall and timber groynes
  • 2 rock groynes and 500m revetments built at Mappleton in 1991
    • £2million built to protect the villaige
  • Groynes and a sea wall at Withernsea and rock armour
  • concrete sea wall, timber groynes and rock armour at Hornsea
  • Gabions South of Hornsea to protect caravan park
  • Easington gas terminal protected by Revetments
  • the Eastern side of spurn head is protected by groynes and rock armour.

Schemes locally successful BUT cause problems down drift:

  • Groynes trap sediment, increasing width of beaches. Protects local area but increases cliff erosion down drift
  • reduction in sediment increases risk of flooding along the Humber estuary and increases erosion along the Lincolnshire coast
  • cost of maintaining sea defences may become too high
  • this makes the schemes unsustainable

Possible schemes:

  • strategic management plan for Holderness for the next 50 years reccomends holding the line and doing nothing - unpopular
  • coastal realignment would be more sustainable
  • sea wall proposed to protect Easington gas terminal - £4.5million - would increase erosiong at Easington. Longer sea wall would cost £7million
  • Offshore reefs - harm the environment
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Soft Engineering - Blackwater Estuary

Part of essex coastline

being eroded at a rate of 0.3 - 1m/year

risk from flooding - sea level rising and south of England is sinking

Hard engineering is too expensive to maintain

Soft engineering:

  • Beach Nourishment
  • marsh stabilisation - planting stakes and Brushwood on water line
  • coastal realignment
  • sea walls breached
  • 21 hectares of farmland flooded to encourage marshland to form

More sustainable:

  • More sustainable in the long term
  • more marshland - larger habitats for wildlife
  • grazing land lost
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Managing Population - Italy

  • low birth rates
  • falling fertility rates
  • ageing population

Population - 58 million in 2005
will decline to 56 million by 2025 (even with net migration)

tendancy to stay at home with parents longer than other Europeans. Reinforced by changing economic circumstances in the past 10-20 years:

  • stay in full time education - more dependant on parents
  • price of housing has increased - difficult for young adults to buy houses
  • fewer well paid but low skill jobs
  • state social security expenditure for families and children id much lower than other EU countries
    • massive effect on when Italians leave home, marry, have a long term relationship or start a family.

government needs to develop policies to deal with the impending crisis, achieve sustainable development and keep a balanced population structure of workers and dependants by:

  • Empowering young people and reversing the 'postponement syndrom' through grants for education and allowances for families
  • structured programme to manage immigration by carefully selecting new migrants to match labour force vacancies
  • allowing access to citizenship rigths for migrants to encourage them to settle and raise families.
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Managing Population- China's one child policy

1950 - pop 0.6 billion
1975 - pop over 0.9 billion, Birth rate of 30 per 1000

Rapid growth would lead to famine and starvation

1979 - introduced one child policy

Some parts of the country it was advice, some parts strictly enforced.

'Carrot and Stick':
Incentives paid to people who followed the policy
People Fined heavily for failing to enforce policy
Compulsory abortions and sterilisations

contraceptive advice freely available
Encouraged late marriages

'Granny police' - encouraged young people in their district to use contraceptives and avoid unplanned pregnancies.

Female infanticide (killing of infants) and abandonment of baby girls - mainly from rural areas. Having a daughter was an economic disaster.
Relaxed rules in rural areas.

2000 - willing to relax and adjust policy, but it stays in place.

2007 - Population 1.3 billion
Without one child policy it would be 25% higher
Birth rate around 14 per 1000
annual growth rate 0.5%
Population momentum slowed

China are concerned about aging Population by 2025

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Managing Population - Iran's Baby boomers

Iran's population was 70,049,262 according to the 2006 census
Nearly 1 quarter of its people aged 15 or younger

  • Large cohort of some 18 million 'baby boomers' - young men and women born between 1979 and 1989
  • throughout much of 1980s pop growth accelerated rapidly
  • then decreased even more quicly to replacemnt level
  • baby boomers into adulthood offers the country possible economic growth
    • could lead to a second baby boom
  • youthful population structure
  • long life expectancy (70)
  • country will have to confront a large proportion of people over 65 compared with younger people
  • 2002 - people over 65 accounted for 5% of whole population. this group will account for almost 25% of population by 2025
  • migration also important demographic concern
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Managing population - Changing population structur

  • undergoing population crisis
  • from 1960s to late 80s they have been characterised by high birth rates and rapidly falling death rates
  • typical stage 2 on the Demographic Transition model
  • 19902 - HIV/Aids
  • spread rapidly
  • spread encouraged by:
    • poor levels of education
    • low status of women
    • mobile population where many migrated to seek work
    • poor levels of basic health care and health education
    • Aids sufferes stigmatised
    • slowness of governments acting to tackle problem
    • high cost of drugs in a poor society


  • encouraged use of contraceptives and family planning
  • policies to combat spread of HIV/Aids - in Uganda ABC Abstain from sex until marriage, Be faithful to one partner and use Condoms
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Rural to Urban Migration - Colombia

Colombia, NorthWest of South America

Rapid urbanisation in second half of 20th century

Push Factors:

  • Mechanisation -> fewer jobs
  • almost impossible to gain ownership of land
  • Insecure - no long term title to land
  • soil exhaustion -> hard to grow crops and get income
  • lack of healthcare
  • lack of education
  • lack of clean running water
  • political instability
  • conflict between guerrillas and government
  • conflict between drug producers and authorities
  • militias and death squads

Pull factors:

  • possible work
  • opportunities that the countryside couldn't supply
  • education
  • freedom
  • 'glamorous city life'
  • more political power

ongoing study:

  • 1986
  • Dr Peter Kettett - Newcastle University
  • Santa Marta
  • Migration to Santa Marta
  • Many developments and growths of the settlement Sanat Marta
  • housing changes as families grow and circumstances change
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