Population
UNIT II
Key Questions
• Will the earth’s population increase to a level that could
lead to a global crisis?
• What patterns exist in the earth’s population densities and
distributions?
• Why are populations growing faster in some areas of the
world than in others?
• How have governments and religions attempted to
influence population growth trends?
• How do geographers measure and study human population
patterns?
• What are the current and past patterns of population
migration and movements?
• What political, economic, and social factors influence
population migration streams?
Population
• Demography
– Study of human populations
• Infrastructure
– Support systems (housing, food, education,
healthcare, roadways)
• Scale of Inquiry
– Size of geographic investigation…global vs.
regional vs. local
Trends
• Populations are growing in poorer areas
– Ex. Africa and Asia
• Critical issue not the growing population
– Critical issue is growth without support
Demographic Accounting equations
• Global population accounting equation
– P0= population at start
– P1= population at end
– B= Births within time interval
– D= Deaths within time interval
– P1=P0 + B - D
What about on a regional/subglobal
level?
• Similar but adds two factors
• IMMIGRATION…think Into
• EMMIGRATION…think Exiting
Demographic Accounting equations
• Sub-Global population accounting equation
– P0= population at start
– P1= population at end
– B= Births within time interval
– D= Deaths within time interval
– I= Immigration
– E= Emmigration
– P1=P0 + B – D + I - E
Population Distribution
• Distribution
– Pattern of people across the earth’s surface
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Throughout history it has been UNEVEN
Cluster around RESOURCES
¾ of people live only on 5% of the earth’s surface
ECUMENE- Earth’s surface where people can live
50/50 split (Urban vs. Rural)
Global Pop Distribution
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~81% of pop lives in LDCs
2 countries have over 1 billion people each
7 Billion worldwide
1 in 2 live in Asia
3 in 5 live in Asia/Europe
Largest concentration: East Asia (China, Japan,
Taiwan, Korea)
• Second largest concentration: S. Asia (India,
Bangladesh, Sri Lanka, Pakistan)
Cont…
• Natural Increase rate
– The percentage growth of a population in a year,
computed as the crude birth rate minus the crude
death rate
– India’s NIR is higher than China’s … what does that
mean?
– Most Asians are subsistence farmers
Cont…
• Third largest concentration: Europe… From
Atlantic to the Ural Mtns.
– Mainly due to Industrial Revolution
– Most Europeans are Urban Dwellers
– Although Asian has a greater number of Urban
Dwellers due to greater population
Density
• Arithmetic Density/Population Density
– Total number of people divided by total land area
– Egypt: 177 people per sq mile
• Physiological Density
– Number of people divided by arable land
– Arable = Farmland
– Ex. Egypt:8,000 per sq mile of arable land
• Agricultural Density
– Farmers per unit of arable land
– Low agri density suggests large farms
– High agri density= many farmers on each piece of farmland
Overpopulation
• Carrying Capacity
– The number of people the area can
sustain/support
– Efforts to increase C.C.
• Japan imports food and supplies
• Israel has improved irrigation
• Saudi Arabia has desalination plants
Cont.
• Overpopulation
– When a region outgrows its carrying capacity
Population Pyramids
• Age-Sex structures
• Helps to evaluate the distribution of ages and
genders in a given population
• Cohort
– A group of people of the same age
– Pop Pyramids can help predict future growth or
problems
Population Pyramids
• Can look towards history to help explain
– Ex. Baby boom
Graying Population
• Dependency ratio
– Ration of people 15-64 vs. the rest
– Why this group?
– In US and Europe the Ratio is growing
– In 2000… first time 60 and overs outnumbered
people under 14
Population explosion
• We are growing EXPONENTIALLY
• Different than linear or arithmetic
• 1st agricultural rev.
• Industrial rev.
• 2nd ag revolution
Theories of Pop Growth
• Thomas Malthus
– Said pop was growing GEOMETRICALLY
– Said food was growing ARITHMETICALLY
– Advocated birth control and celibacy (positive
checks)
– Negative checks (war, starvation, disease)
Pop
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1650-1/2 billion
1820- 1 billion
1930- 2 billion
1975- 4 billion
2000- 6 billion
2012- 7 billion
Other theories
• Karl Marx-uneven distribution of resources
• Boserup- increase subsistence farming
• Neo-Malthusians-we must reach a sustainable
level
Demographer’s tools
• Crude birth rate: number of live births per 1000
people
• Crude death rate: number of deaths per 1000
people
• Infant mortality rate: infant deaths per 1000
births
• Life expectancy
• Fecundity: ability of a woman to conceive
• General Fertility rate: number of births per 1000
women in the Fecund years
Cont…
• Total fertility rate: predicted number of births
a woman will have thru the fecund years
– A TFR of 2.1 in called replacement level
fertility…leads to zero pop growth
– Global NIR or RNI in 2006 was 1.2 (0 means no
growth)
– MDCs = .1
– LDCs = 1.5
China
• Female infanticide due to 1 child policy
• Leads to increased HIV
The Demographic
Transition
(Ch 2.3A)
The Classic Stages of Demographic
Transition
Stage 1
Stage 2
Stage 3
Stage 4
Birth rate
Natural
increase
Death rate
Time
Note: Natural increase is produced from the excess of births over deaths.
Lesson Plan: The Demographic Transition, Activity One
Stage 1: Low Growth
• Very high birth/death rates
• Occurred during most of human history…no
country in stage one today
• #of births = #of deaths (zero population growth)
Stage 2: High Growth
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Very high birth rates/declining death rates
Very high rate of natural increase
New technologies developed during the Industrial Revolution
helped farmers produce more food -especially in N. America &
Europe (@1800)
Diffusion of medical technologies helped populations of LDC’s in
Africa, Asia, and Latin America grow in the mid-20th century.
Stage 3: Moderate Growth
•birth rates rapidly decline/death rates
continue to fall/rate of natural increase slows
Stage 4: Low Growth
• Very low birth/death rates
• slow rate of natural increase
• Zero population growth
Scatter graphs
• Used to investigate the relationship between two variables
for a set of paired data.
• Trend line should be drawn that…
– Follow the trend of the data
– Join as many points as possible
– Leave an equal number of unjoined points on either side
Epidemiological Transition model
• Focuses on causes of death at each stage of the
Demographic transition model
• 4 stages (matches DTM)
• Stage 1- Pestilence and Famine
– Ex. Black plague
• Stage 2- Receding Pandemics
• Stage 3- Degenerative and Human created diseases
– Cancer, heart attacks, etc…
• Stage 4- Delayed Degenerative disease
– Still there but doesn’t occur as fast
• Stage 5?- Reemergence of infectious and parasitic
disease
– Increase mobility
Migration
Population Movement
• Friction of Distance
– Difficulty of distance
– It has been reduced
• Space time compression
– Friction of distance being reduced through tech
• Spatial interaction
– Interaction between two places
Migration
• The process of PERMANENTLY moving from
your home region and crossing an
administrative boundary
• Current…174 million have migrated outside
their home country
Migration Stream
• A pathway from a place of origin to a
destination
• PLACE DESIRABILITY
– Possession of Positive features
• Net in-migration
– More IMMIGRATION
• Net out-migration
– More EMMIGRATION
Migration Streams
• Usually have COUNTERSTREAMS
Push/Pull factors
• PUSH… negative factors
• PULL… positive factors
Voluntary vs. Involuntary
• Voluntary
– They have the option
• Involuntary
– They are pushed from their land
• Ex. N. Atlantic slave trade
Refugees
• Migrants that flee some sort of persecution or
abuse
• INTERNATIONAL REFUGEES
– Flee to other countries
• INTRANATIONAL REFUGEES
– Flee to another area of the country they live in
– AKA internally displaced people
Major areas of Dislocation and
Refugees
Sub-Saharan Africa
• Largest refugee crisis
• Rwanda and Congo- Tribal/Ethnic conflicts
• Darfur region(Sudan)- Religious/Ethnic tension
between North and South, Muslims and
Animists, and government and rebels have led
to dislocation
• Zaire, Tanzania, Sierra Leone, Angola, Burundi
– War related refugees
Middle East
• (may include N. Africa)
• Migration streams include
– Palestinians after formation of Israeli state to
neighboring SW Asia: Jordan, Syria, and Egypt
– Kurdish from Iraq and Afghanistan during Soviet
occupation in the 1980s
Europe
• In the Balkins… Fall of Yugoslavia led to largest
refugee crisis in Europe since WWII…nearly 7
million
SE Asia
• The Vietnam war created 2 million refugees
• Cambodia
– Violent government transition led to 300,000
refugees
• Burma
– (now Myanmar)
– Dislocated thousands
S. Asia
• Afghani refugees to neighboring Pakistan
• Sri Lanka … nearly 1 million citizens dislocated
by a feud with the Sinhalese government
Internal Migration
• Interregional Migration
• Intraregional Migration
• Urban Migration
– CounterUrbanization
US migration patterns
• Have shifted west and south
• Great Migration
– African Americans moving North after 1900
(~WWI)
– 1970s they moved back South
– Overall shift South for better weather and
opportunities (Jobs moved South)
Aging Industry
• Rustbelt (northeast)
• Sunbelt (South)
After WWII migration
• Jewish immigrants to Israel from all over
including Russia and Germany
• E. German emigration to other areas to avoid
Soviet control
• Asia (Philippines, Vietnam, India) => USA
• N. Africa/Turkey to Europe (France, Germany,
and England)
Migration Selectivity
• Decision to migrate is a predictable pattern
based on age, income, and other
socioeconomic factors
• Age most relevant (18-30)
Brain Drain
• Most educated leave for more distant job
opportunities
• Ex. Appalachian region in Kentucky
Gravity Model
• Larger places attract more migrants
• Also… closer places also attract more migrants
than farther places
• Migration is therefore directly proportionate
to population size and inversely proportionate
to the distance between two places
Ravenstein Migration Laws
• Majority of migrants travel short distances
– Step migration
– Intervening opportunities
– Intervening Obstacles
Cont…
• Migrants who travel farther will tend to move
to large cities
• Rural residents are more likely to migrate
• Families are less likely to migrate across
borders
• Every migration steam has a counterstream
Chain Migration
Migration transition
• Stage 1- searching local for necessities
• Stage 2- Countries are taxed for resources
(due to NIR) so people move out
• Stage 3-Internal Migration… cities to suburbs
• Stage 4- Intraregional