Transcript population notes

POPULATION
Chapter 2
H. J. deBlij
Where in the World Do People
Live and Why?
• Arithmetic population density: Measure of
total population relative to land area
Where in the World Do People
Live and Why?
• Arithmetic population density: Measure of
total population relative to land area
• Physiologic population density: Population
per unit area of agriculturally productive
land (takes this map into account)
• Physiologic population density: Population
per unit area of agriculturally productive
land (takes this map into account)
Population distribution
Descriptions of locations on the Earth’s surface where
individuals or groups (depending on the scale) live
D
On this map, one dot represents 100,000 people
Population distribution
Descriptions of locations on the Earth’s surface where
individuals or groups (depending on the scale) live
C
A
B
On this map, one dot represents 100,000 people
Major World Population Clusters
A. East Asia: ¼ of world population
B. South Asia: Bound by the Himalayas to the north
and a desert in Pakistan
C. Europe: Population concentrated in cities
D. North America: Megalopolis
Why Do Populations Rise or Fall
in Particular Places?
• Thomas Malthus
– An Essay on the Principles of Population (1798)
– Population growing exponentially
– Food supplies growing linearly
• What happened?
– Expansion of food supply sources (globalization)
– Increase in agricultural productivity
(exponentially)
Doubling Time
• Number of years for a
population to double
in size (like a bank
deposit at compound
interest)
• Decreased doubling
time (rapid growth),
then increased
doubling time (growth
slowed down)
Doubling time = 54 years
Doubling time = 45 years
Rate of Natural Increase
• Difference between births and deaths
• Does not include immigration and emigration
Rate of Natural Increase
• Difference between births and deaths
• Does not include immigration and emigration
Total Fertility Rate (TFR)
• The average number of children per woman
• TFR needed to maintain the population size: 2.1
Total Fertility Rate (TFR)
• The average number of children per woman
• TFR needed to maintain the population size: 2.1
Population Growth in India
Significant
demographic
variations within
countries: Higher
growth rates in
northeastern India,
lower rates in
southeastern India
Population in India
• 1950s: Population planning program
• 1960s: National population planning program
• 1970s: Beginning of forced sterilization program
for men with 3 or more children; 22.5 million men
sterilized
• 2004: Beginning of guns-for-sterilization program
in Uttar Pradesh
• Today: Use of advertising and persuasion to lower
birth rates in most states
The Demographic Transition
• Changes in birth, death, and natural increase rates
• Decline in death rates followed by decline in birth
rates, resulting in a low or stable growth rate
World Birth Rates
Number of births in a year per 1,000 people
World Birth Rates
Number of births in a year per 1,000 people
World Death (Mortality) Rates
Number of deaths in a year per 1,000 people
World Death (Mortality) Rates
Number of deaths in a year per 1,000 people
The Demographic Transition
Why Does Population
Composition Matter?
• Components of population composition
– Gender distribution
– Age distribution
• Population pyramid: Graphic depiction of
population by percentage in each age group,
divided by gender
Population Pyramids for Poor Countries
• High infant mortality
• Short life expectancy
• Rapid population growth
Population Pyramids for Wealthy
Countries
• Low infant mortality
• Long life expectancy, especially for females
• Little or no growth, even natural decrease
How Does The Geography Of Health
Influence Population Dynamics?
World Infant Mortality
Deaths of babies less than one year of age, per 1,000 live births in a year
Infant Mortality in the United States
World Life Expectancy
Number of years a person born now can expect to live
World Life Expectancy
Number of years a person born now can expect to live
Mother’s Index
• Based on 10 barometers of well-being among
mothers and children
• Strongly influenced by poverty and warfare
Mother’s Index
• Based on 10 barometers of well-being among
mothers and children
• Strongly influenced by poverty and warfare
Diseases
• Sources of diseases
– Infectious diseases: Spread from person to person
•Vectored: Spread through intermediary, such as an
insect
•Nonvectored: Spread directly from person to person
– Chronic or degenerative diseases: Diseases of old age
– Genetic or inherited diseases: Passed through genes
• Spread of diseases
– Endemic: Present in small area
– Epidemic: Spreads over large region
– Pandemic: Spreads worldwide
Causes of Death in the United States
• Chronic diseases
reflecting longer
life expectances
• Decline in deaths
from infectious
diseases
HIV/AIDS
• Became worldwide
concern in 1980s (but
probably present in
Africa before then)
• Infection long before
symptoms appear
• Social stigma
• Many deaths among
young adults
Effect of AIDS on population structure
of South Africa
AIDS Impact on Children
Drawing by a Pokot
boy in Kenya, showing
him working in the fields
and caring for cattle to
assist sick family
members
Sparrow Rainbow Village, a
hospice for child AIDS patients
near Johannesburg, South
Africa
How Do Governments Affect
Population Change?
• Expansive population policies
– Anti-capitalist ideologies (e.g., Maoist China,
Soviet Union)
– Combating declining birth rates, aging
populations (e.g., Europe)
• Eugenic population policies (e.g., Nazi
Germany)
• Restrictive population policies
The Case of China
The Case of China
The Case of China