Transcript Document 7321929

Population
Chapter 2
Where do people live and why?
Demography- the study of population
• Demographers use concepts
such as:
•
Population Densitymeasure of total population
relative to land size- also
called:
• Arithmetic Population
Density- assumes even
density over the land
US is 79/sq mile
Egypt is 73.3 million
total
pop, 190/sq
mile
• Physiologic Population
Density- total population per
unit area of arable (farmable)
land
– Does not count
water/mountains/deserts
where no people live
– Egypt- 6319/sq mile when
measured like this
Arithmetic Population Density
Fig. 2-4: Arithmetic population density is the number of people per total land
area. The highest densities are found in parts of Asia and Europe.
Physiological Density
Fig. 2-5: Physiological density is the number of people per arable land area. This is a good
measure of the relation between population and agricultural resources in a
society.
Population Density – Egypt
•All but 5% of Egyptian
people live in the Nile
river valley
•It is the only area in the
country that receives
enough moisture to allow
intensive cultivation of
crops
Population Distribution• descriptions of the locations where people
(or groups) live
•
Dot maps provide a good representation
of distribution
•
People unevenly distributed across the
globe
World Population Cartogram
Fig. 2-1: This cartogram displays countries by the size of their population rather
than their land area. (Only countries with 50 million or more people are named.)
World Population Distribution
Fig. 2-2: World population is very unevenly distributed across the Earth’s surface
and it can be compared to climate distribution.
Expansion of the Ecumene
5000 B.C.–A.D. 1900
Fig. 2-3: The ecumene, or the portion of the Earth with permanent human settlement,
has expanded to cover most of the world’s land area.
Population Distribution
• Densely populated regions
– Low lands
– Fertile soil
– Temperate climate
• Sparsely Populated Regions
– dry lands
– wet lands
– high lands
– cold lands
Major Population Clusters (p. 40-41):
•
East Asia- Largest cluster (1.55 billion people)
• Contains China (1.3 billion), Korea and Japan
•
South Asia- 2nd largest cluster (1.45 billion
people)
• Contains India, Pakistan, Bangladesh, and Sri Lanka
– Bangladesh’s pop density in the rural areas is between 3000-5000
people per sq mile
•
Europe- 3rd largest cluster (728 mil)
• Population reflects coal fields and cities, not farmland and rivers
as in Asia
•
North America- 4th largest cluster (329.4 million)
• Concentrated in N.E. US and S.E. Canada
• Reflects a megalopolis (overlapping urban areas)- from BostonWashington D.C.
Reliability of Population data
• Census- count of the entire population of a country,
performed every 10 years in the US
Used to give government money for building schools, parks,
social services, etc.
– Does not count homeless, minorities, and others so they
may not get funding for help
– Us undercounted in 2000 by about 3.3 million, what about
less well off countries???
–
• Other agencies also gather data on world populations:
–
–
–
–
World Bank
United Nations
Population Reference Bureau
Each has inconsistencies in their statistics
Why do Populations Rise or Fall in
Particular Places?
• In 1960 Paul Ehrlich published Population Bomb, in which he
warned that the world’s population was increasing too quickly
and was outpacing our food production
• Thomas Malthus- wrote: An Essay on the Principles of Population
– population was increasing faster than food production
– Said that food grew linearly while population grew exponentially
• Was wrong, because he did not predict that mercantilism,
colonialism, and globalization would bring the world in closer
contact and spread crops and farming methods
• Neo-Malthusians- followers of Malthus today that don’t believe
every detail, but are concerned with population growth and
feeding the world
Food and Population, 1950–2000
Malthus vs. Actual Trends
Fig. 2-20: Malthus predicted population would grow faster than food
production, but food production actually expanded faster than
population in the second half of the twentieth century.
Population Growth at Different
Scales
• Terms concerned with population growth:
– Rate of Natural Increase- births minus deaths
over a period of time (year)
– CBR (crude birth rate)- # of live births per year
per thousand people in a population
– CDR (crude death rate)- # of deaths per year
per thousand people
Crude Birth Rates
Fig. 2-8: The crude birth rate (CBR) is the total number of births in a country per 1,000 population per
year. The lowest rates are in Europe, and the highest rates are in Africa and several Asian
countries.
Crude Death Rates
Fig. 2-12: The crude death rate (CDR) is the total number of deaths in a country per 1,000
population per year. Because wealthy countries are in a late stage of the
demographic transition, they often have a higher CDR than poorer countries.
Natural Increase Rates
Fig. 2-7: The natural increase rate (NIR) is the percentage growth or decline in the population of a
country per year (not including net migration). Countries in Africa and Southwest Asia
have the highest current rates, while Russia and some European countries have
negative rates.
Terms, cont.
• Demographic Change- Measured with a formula:
•
B-D+I-E (births –deaths+immigration-emigration)
•
TFR (total fertility rate)- average number of births a woman
will have over her lifetime
–
•
2.1 is replacement rate (a woman in a country must have this
many children for pop to grow)
48)
Doubling Time- time it takes for a population to double (p.
Invest $100 at 10% interest, it will take 7 years to double over and
over again
– Today our pop is doubling every 51 years (it recently slowed & was
much faster)
– The world’s growth rate is 1.4%, 80 mil people added each year
–
Total Fertility Rates
Fig. 2-9: The Total fertility rate (TFR) is the number of children an average woman in a society will
have through her childbearing years. The lowest rates are in Europe, and the highest are
in Africa and parts of the Middle East.
World Population Growth
1950–2000
Fig. 2-6: Total world population increased from 2.5 to 6 billion in this half century. The natural
increase rate peaked in the early 1960s and has declined since, but the number of
people added each year did not peak until 1990.
Growth at the Regional Scale
• High growth rates are associated with low
standing of women (no education, male
dominated)
• China is world’s largest, but soon to take over
is India
• Japan’s pop is shrinking, along with other
wealthy countries
• Russia is shrinking- horrible conditions (drug
use, alcoholism, economics) lower births &
raise deaths
• South America is experiencing significant reduction in natural
population growth rates, whose rates were high a generation ago.
Brazil is down from 2.9 in the mid 1960’s to 1.3 % today.
• Economically wealthier countries have a declining growth rates.
Economically prosperous countries have high levels of education,
later marriage, & family planning which lower the population
growth. Russia’s declining population growth rates are due to
social dislocation that has come in the wake of the collapse of
the Soviet Union.
• Cultural traditions also influence rates, like religion has an impact
on family planning.
Pop growth at the Local Scale
• Most countries have variations within their borders
• Population trends show that Sub-Saharan Africa’s growth
rate is higher than India in spite of the AIDS epidemic.
• Muslim countries of North Africa have high growth rates.
• Saudi Arabia has one of the highest growth rates in the
world.
• India- pop explosion in the 50’s
– Encouraged family planning (birth control, forced sterilization
after 3 children for men)
– Led to riots & 22.5 million sterilizations
• TODAY: guns for sterilization program- 2 sterilizations for
shotgun, 5 for revolver
– Landowners abusing laborers and sterilizing them for guns
Maharashtra, India. A sign reads “free family planning sterlization
operation” closed in 1996.
The Demographic Transition of Great
Britain
• In Great Britain, demographers used church data such as
baptisms and funerals to study changes in the population.
• The expected rate of natural increase may vary over different
periods of time. To study the natural increase, demographers
calculate the crude birth rate (CBR) and the crude death rate
(CDR).
• Before the Industrial Revolution, Great Britain experienced high
birth rates and death rates with little difference between the two.
The result, a low population growth.
• After industrialization, the death rate started to fall due to better
medicines and standards of living, the population began to
explode.
HIV/AIDS Prevalence Rates, 2002
Fig. 2-26: The highest HIV infection rates are in sub-Saharan Africa. India and China
have large numbers of cases, but lower infection rates at present.
• From the 1800s through 1950 population
continued to growth at a low, but stable rate
because the birth rates were still higher than
the death rate.
• Today both birth and death rates are low,
resulting in slow, stabilizing population growth.
• Britain provides a model for the four stages in a
demographic cycle. Demographers call the
sequence of stages in population growth the
demographic transition model.
Demographic Transition in England
Fig. 2-14: England was one of the first countries to experience rapid population growth in the
mid-eighteenth century, when it entered stage 2 of the demographic transition.
The Demographic Transition (p.
54)
• Low growth stage (also called low stationary)high birth rate and high death rate, little long
term growth
• High- growth stage (also called early
expanding)- high birth rate, declining death
rate- large growth of population
• Moderate-growth stage (also called late
expanding)- declining birth rate, low death rateslow continued pop. Growth
• Low-growth stage (high stationary)- low birth
rate, low death rate- very low rate of growth
• Stage 1: epidemics, plagues, famines keep
death rates high, lots of births required to
survive
• Stage 2: usually corresponds with technological
development- medicines and farming improve
• Stage 3: associated with urbanization and the
economic cost of having more children (no
longer needed for farming)
• Stage 4: associated with highly educated and
working women
Population Composition
• Shows the number of men, women, and their
ages in a population
• Population composition is easily displayed in
a population pyramid
•
Pyramids allow geographers to take a
quick look and tell the following:
– Ages, growth rates, males vs. females, wealth,
cdr, cbr, and many other things
Percent of Population under 15
Fig. 2-15: About one-third of world population is under 15, but the percentage by country varies from
over 40% in most of Africa and some Asian countries, to under 20% in much of Europe.
Population Pyramids in U.S. Cities
Fig. 2-16: Population pyramids can vary greatly, with different fertility rates (Laredo vs. Honolulu), or
among military bases (Unalaska), college towns (Lawrence), and retirement
communities (Naples).
Rapid Growth in Cape Verde
Fig. 2-17: Cape Verde, which entered stage 2 of the demographic transition in about 1950, is
experiencing rapid population growth. Its population history reflects the impacts
of famines and out-migration.
Moderate Growth in Chile
Fig. 2-18: Chile entered stage 2 of the demographic transition in the 1930s, and
it entered stage 3 in the 1960s.
Low Growth in Denmark
Fig. 2-19: Denmark has been in stage 4 of the demographic transition since
the 1970s, with little population growth since then. Its population
pyramid shows increasing numbers of elderly and few children.
Important Population Terms that
Show the Condition of a Country:
• Infant Mortality Rate (IMR)- the number of deaths during
a baby’s first year of life per 1000
• Child Mortality Rate (CMR)- the number of deaths during
ages 1-5 per 1000 children
• Life Expectancy- average age that someone will remain
alive in a country
•
•
•
•
These reflect overall health of a society
AIDS has lowered life expectancy for Sub-Saharan Africa
Women live longer than men (why?)
World average was 68 for women and 64 for men recently
• How do these statistics show the condition of a country’s
development???
Aging Populations
• To replace the population, TFR must be 2.1.
-
TFR in Bologna, Italy is 0.8
Why are women having fewer children?
• What are the impacts of an aging population
on a country?
• What are the “solutions” to an aging
population?
Dependency Ratio
• 0-14 = Dependents
• 15-64 = Workers
• 64+ = Dependents
• DR = Number of Dependents (0-15 and 65+) X 100
Number of Working-age (16-64)
Population policies:
• -set up by governments with the purpose of
influencing the overall growth rate or ethnic
ratios within the population
• 3 types:
• Expansive Population Policy• Encourage large families and raise the rate of natural
increase
• May be done because populations are aging and declining
– Ex: Sweden suggested showing racier programming at night to
raise birth rates
– -Tax breaks, job flexibility, cash payments by government
• Eugenic Population Policy• Done in the past and are designed to favor
one racial or cultural sector of the population
over others
• Nazi Germany is an example
• Done covertly through unfair taxation, biased
allocation of resources, etc.
• Restrictive Population Policy– Seek to reduce the rate of natural increase
• Most popular in today’s societies
• China’s one child policy is an example
Sex Ratio
• Sex Ratio: number of males per hundred
females
• In general more males are born than
females
• Males have higher death rates
• Examples:
– Europe and North America = 95:100
– Rest of World = 102:100
– Major issue for China with 1 child
policy!
Use of Family Planning
Fig. 2-22: Both the extent of family planning use and the methods used vary widely by
country and culture.
Crude Birth Rate Decline, 1981–2001
Fig. 2-21: Crude birth rates declined in most countries between 1981 and 2001
(though the absolute number of births per year increased from 123 to 133
million).