Powerpoint Presentation Natural Disasters, 5e

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Natural Disasters and the Human
PopulationNatural Disasters, 6th edition,
Chapter 1
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Natural Disasters

• 360 natural disasters in 2005, 91,900 people
  killed, 157 million people affected, 159 billion
  dollars damage
• 305 natural disasters in 2004, 280,000 people
  killed, 150 million people affected, 150 billion
  dollars damage
• More than 83,000 people killed by natural
  disasters in 2003

• 2005 - 73,338 of the dead in Pakistan's Quake
  Zone
• 3.3 million left homeless
• 2nd wave of deaths from winter storm
• 2005 Hurricane Katrina
• 2004 226,408 dead in Indian Ocean Tsunami
• 2003 - Bam, Iran earthquake 41,000 people

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Human Fatalities in Natural Disasters

• Sawtooth-shaped curve caused by largest natural
  disasters
• Biggest killers (in order) hurricanes,
  earthquakes, floods, severe weather, landslides,
  volcanic eruptions, tornadoes and tsunami
• Most mega-killer disasters occur in densely
  populated belt through Asia, along Indian Ocean
  number of fatalities is proportional to density
  of population

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Human Fatalities in Natural Disasters

• Most mega-killer disasters occur in densely
  populated belt through Asia, along Indian Ocean
  number of fatalities is proportional to density
  of population

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Economic Losses from Natural Disasters

• Destruction and damage to structures, loss of
  productivity and wages
• Increase in economic losses over time is result
  of increase in human population and urbanization,
  e.g. United States.
• Most expensive events caused by storms and
  occurred in U.S., Europe and Japan developed
  countries
• Most Casualties in undeveloped countries, e.g.
  Asia.

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Natural Hazards

• Hazard exists even where disasters are infrequent
• Evaluate site risk
• Mitigation prior to event
• Engineering, physical, social and political plans
  and actions to reduce death and destruction from
  natural hazards
• Mitigation after event
• Rebuilding and re-inhabiting same site
• Case history Popocatepetl Volcano, Mexico
• Eruptions in 822, 1519 and beginning again in
  1994
• Currently 100,000 people living at base

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Magnitude, Frequency, and Return Period

• Inverse correlation between frequency (how often
  it occurs) and magnitude (how big it is) of a
  process
• Frequent occurrences are low in magnitude, rare
  occurrences are high in magnitude
• Small-scale activity is common, big events are
  rare
• Larger the event, longer the return-period
  (recurrence interval)

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The 20th Century Was Unique

• Population growth at unprecedented and
  breathtaking rate, doubling twice
• Increased numbers of people in hazardous settings

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Overview of Human Population History

• Difficult to assess early human population growth
• Human species began approximately 160,000 years
  ago, with a few thousand people
• Human population has grown to 6.5 billion people
  in 2006
• Growth rate is exponential

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The Power of an Exponent of Growth

• Visualize in terms of doubling time
• Number of years for population to double in size,
  given annual percentage growth rate
• Doubling time 70
• growth rate/year
• Example of interest paid on money
• Linear growth 1000 100 / year
• Exponential growth 1000 7 / year
• Example of water lily plant in pond
• Doubles in size every day
• Covers half the pond the day before it covers the
  whole pond

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The Last 10,000 Years of Human History

• Flat population growth curve until 8,000 years
  ago
• Agriculture established
• Domestication of animals
• Growth rate increased to 0.036/year
• By 2,000 years ago, population 200 million
  people
• Better shelter, food and water supplies faster
  population growth
• Growth rate of 0.056/year
• By 1750, population 800 million people

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The Last 10,000 Years of Human History

• By 1750, population 800 million people
• Establishment of public health principles, causes
  of disease recognized
• Birth rates soared, death rates dropped
• By 1810, population 1 billion
• By 1925, population 2 billion
• By 1960, population 3 billion
• By 1974, population 4 billion
• By 1987, population 5 billion
• By 1999, population 6 billion
• By 2012, projected population 7 billion

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The Human Population Today

• Present population (6 Billion )
• Growth rate 1.3/year
• Doubling time 53 years
• Growth rate
• fertility (birth) rate mortality (death) rate
• Human population grows by about 80 million people
  per year

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Future World Population

• Demographic transition theory
• Mortality and fertility rates decline from high
  to low levels because of economic and social
  development
• Population Reference Bureau estimates world
  population growth rates are dropping
• From 1.8 in 1990 to 1.3 in 2003
• Due to urbanization and increased opportunities
  for women

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Future World Population
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Future World Population

• BUT population explosion continues
• From 1950 to 2000 population grew from 2.5
  billion to 6 billion
• Growth rate of 1.3/year means population of 9
  billion in 2050
• Consider no. of births / woman to predict 2150
  population
• Average 1.6 children/woman 3.6 billion
• Average 2 children/woman 10.8 billion
• Average 2.6 children/woman (current average) 27
  billion

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Demographic Divide

• Wealthy countries low birth rates, long life
  expectancies
• Poor countries high birth rates, short life
  expectancies
• Examples of Japans shrinking population vs.
  Nigerias expanding population

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Mathematical Extrapolation

• Too many people?
• Crowding in cities
• Crime
• Pollution
• Illegal migration
• Disease
• Room for more people?
• Entire world population could fit inside 42 km x
  42 km square
• Consider carrying capacity

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Carrying Capacity

• How many people can Earth support?
• Calculations of carrying capacity vary
  considerably
• Increasing amounts of food can be produced
• People can migrate from areas of famine or
  poverty to less crowded or wealthier areas
• BUT Earths resources are finite, so solutions
  are temporary

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Carrying Capacity

• Example of Rapa Nui (Easter Island)
• Isolated Pacific island with poor soil and little
  water
• Settled by 25-50 Polynesians in 5th century
• Survived easily on chickens and yams, plenty of
  free time
• Developed elaborate competition between clans
  with moai (statues)
• Civilization peaked at 1550, with population of
  about 7,000

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Carrying Capacity

• Example of Rapa Nui (Easter Island)
• Reached by a Dutch ship in 1722
• Found about 2,000 people living in caves
• Primitive society, constant warfare
• Rapa Nuis carrying capacity had been drastically
  lowered by societys actions
• Transportation of moai had required cutting down
  trees
• Erosion of soil made yams scarce
• Lack of canoes made fishing difficult and escape
  impossible

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End of Chapter 1