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Population History and Statistics
Reading Quiz this Friday over Pages 34-44
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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 Food Supply-in the 1960s the fear of rapid population growth outpacing food supply was a main concern. The Green Revolution helped to ease the gap by introducing higher yield strains of rice, wheat and corn. Scientists continue to warn that an increase in population and the increased consumption of meat could lead to a global food crisis. Health-infant mortality, child mortality and over all life expectancies are concerns of demographers. Women-efforts to curb population growth have the greatest impact on women-some societies practice female infanticide or female children are malnourished or deprived of care. Where women are educated-birth rates decline. Migration-the movement of millions of people across international boundaries and internal migration to evade poverty or war or environmental disasters are also concerns of demographers. (train in Jakarta, Indonesia-one of the world’s most populous cities with 11 million people)
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Earth: The Apple of Our Eye Activity
Slice an apple into quarters-remove ¾=oceans Slice the quarter left (land) into 4 pieces set aside 3 = 2/3 are too rocky, wet, cold or covered by cities 1/32 left –peel the remaining piece=the topsoil surface that can grow food 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.
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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)
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Distribution- ¾ of the world’s population lives on only 5% of the land
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. Distribution-arable land is only a fraction of the Earth’s surface- Often population maps are shown by using dots to represent populations. We have always been unevenly distributed-but the uneven distribution intensified in the 20th century. Numbers are very important-every 10 years since 1790 the US govt. has done an official nation-wide census or count of the population to determine representation in Congress and the distribution of federal aid. Mayors of big cities have been upset in recent years since inner cities are notoriously undercounted in the census. Why? The US Census Bureau also gathers world population data. United Nations officials also keeps statistics as does the World Bank and the Population Reference Bureau. Growth rates, health and food availability are often estimates and are subject to error and inconsistency.
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World Population Density
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Physiologic Population Density –
number of people per unit area of agriculturally productive land (takes this map into account).
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Physiologic Population Density Luxor, Egypt
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.
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Major Population Concentrations
East Asia South Asia Europe North America
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Major Population Concentrations
East Asia-1/4 of the world’s population is here-China 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.
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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. Top Kolkata, India street scene Bottom-China’s One Child Policy Poster
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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.
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Street scene in Kolkata, India
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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
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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
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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
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Population Growth From Dawn of History to 1820 to reach 1 billion
1970s only 12 years to add another billion. Then a decade for another billion. billion-world population increased from 3 to 4 billion in 14 years billion-from 4 to 5 billion in 13 years billion-from 5 to 6 billion in 12 years A growth rate of 1 billion people per decade. By 1997 growth rate was 1.5% - today 1.4%
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The People Bomb Population Growth Video
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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 CBR-CDR. 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 Birth Rate is the total number of live births in a year per 1,000 people in a society. A crude birth rate of 20 means that for every 1,000 people in a country-20 babies are born over a one-year period. Crude Death rate is the total number of deaths in a year for every 1,000 people. Natural increase rate is the percentage by which a country grows each year. If the CBR is 20 and the CDR is 5 the NIR is 15 per 1000 or 1.5 this excludes migration or immigration.
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Crude Death Rates show less world wide variability than do birth rates due to widespread availability of at least minimal health care and a generally youthful population in the developing nations where death rates are frequently lower than in “old age” Europe. Crude Death Rates
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Total Fertility Rate (TFR) of 2.1 to 2.5 children per
TFR is the average number of children that would be born to each woman if during her child-bearing years, she bore children at the same rate as women of those ages actually did in a given year. It is age-adjusted, thus 2 nations with identical birth rates may have quite different fertility rates and prospects for growth. Total Fertility Rate (TFR) of 2.1 to 2.5 children per woman is considered “replacement level.”
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