Transcript Population History and Statistics

Population History and Statistics
Reading Quiz this Friday over Pages
34-44
Population
• Demographics is the
study of human
population distribution
and migration.
• Key Issues of
Demographics are:
– Food Supply
– Health and life
expectancy
– Status of women
– Migration
People are NOT distributed evenly across the Earth.
Population is clustered in the mid latitude climates and
relatively sparse in the dry and polar climates or the
highlands.
Population Distribution
• As a general rule, large settlements will not be
found in the following categories of locations:
– Places that are too wet (rain forests)
– Places that are too high (high elevations)
– Places that are too cold (Arctic or tundra)
– Places that are too dry (deserts)
However, people will live where it is too hot (air
conditioning makes this possible)
• Distribution- ¾ of the world’s population lives on
only 5% of the land. Very uneven distribution was
intensified in the 20th cent. as population soared. 2/3
of the pop. lives near an ocean or river.
• Carrying capacity-the number of people that can be
supported in an area given the technology of
production.
• Density-the measure of the number of people per
square mile/kilometer, etc.
– Arithmetic density-total number of people
divided by the total land area. It is the most
common statistic given.
– Physiologic density-is the number of people per
unit of arable (farmable) land.
World Population Density
Physiologic Population Density –
number of people per unit area of agriculturally
productive land (takes this map into account).
Physiologic
Population Density
Luxor, Egypt. Egypt’s
arable lands are
along the Nile River
Valley.
Moving away from the
river a few blocks, the
land becomes sandy
and wind-sculpted.
Major Population Concentrations
East Asia
South Asia
Europe
North America
Major Population Concentrations
• East Asia-1/4 of the
world’s population is hereChina with 1.3 billion.
• There are ribbon like
extensions in China along
the Chang and Huang
rivers, but most live on the
east coast.
• Other areas include Japan,
Korea and Vietnam.
• Most people are farmers,
not city dwellers.
Asia
• India has reached
1 billion and rising.
• China imposed 1 child
policy in the 1980s
and growth rate
dropped from 1.2% to
1% by late 1990s, but
has 1.3 billion.
• East Asia as a whole
has a growth rate of
.9% which is half the
rate of 20 years ago.
Major Population Concentrations
• South Asia-the 2nd major
population cluster.
• Like East Asia there are
finger-like extension of
dense pop. that follows
the Ganges and Indus
rivers.
• There are 1.5 billion in
South Asia and India
recently passed the 1
billion mark.
• Bangladesh (size of Iowa)
with 141 million.
Major Population Concentrations
• Europe-the 3rd in population
with 700 million.
• Europe is very urbanized
with 75% to 90% living in
cities.
• Europe’s population
distribution is not closely
tied to terrain, but more
closely tied to coal fields.
• Population density varies
from the highest in the
Netherlands to very low in
Iceland.
Closely spaced houses in
Amsterdam, Netherlands
Major Population Concentrations
• North America- East Central US
and SE Canada equals ¼ the size
of the smallest Eurasian
concentration.
• Unlike Europe, North America
has large areas of sparsely
populated regions.
• Megalopolis Boston to
Washington, D.C. which
includes New York, Philadelphia
and Boston.
• Other major population
concentrations: Chicago,
Detroit, Cleveland, San
Francisco, Los Angeles and San
Diego.
Skyscrapers of Manhattan
New York
• Demographic
Change is calculated
by looking at the
original population,
adding births,
subtracting deaths,
adding immigrants
and subtracting
emigrants to equal
total population.
• Or OP = B – D + I – E
= TP
Population Growth
• From Dawn of History
to 1820 to reach 1
billion
• 1820-1930 to reach 2
billion
• 1970s only 12 years
to add another
billion.
• Then a decade for
another billion.
The People Bomb
• Population Growth Video
• Crude death rate-the number of deaths per 1,000 each
year.
• Crude birth rate-the number of births per 1,000 each
year.
• Natural increase (NIR)rate-the % by which a population
grows in a year. Computed by subtracting the % of CBRCDR.
• Total Fertility Rate (TFR) the number of children born
to women of childbearing age-usually reported as a
percentage.
• Dependency ratio-the number of people who are too
young or too old to work compared to the number of
people old enough to work.
Crude Death Rates
Total Fertility Rate (TFR) of 2.1 to 2.5 children per
woman is considered “replacement level.”