GEOG101 Chapt06 lecture

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GEOG101 Chapt06 lecture

  1. 1. Overview <ul><li>Population Growth </li></ul><ul><li>Population Definitions </li></ul><ul><li>The Demographic Transition </li></ul><ul><li>The Demographic Equation </li></ul><ul><li>World Population Distribution </li></ul><ul><li>Population Density </li></ul><ul><li>Population Data and Projections </li></ul><ul><li>Population Controls </li></ul><ul><li>Population Prospects </li></ul>
  2. 2. Population Geography vs. Demography <ul><li>Population geography </li></ul><ul><ul><li>Focuses on the number, composition, and distribution of humans in relation to variations in the conditions of earth space </li></ul></ul><ul><ul><li>Spatial analysis </li></ul></ul><ul><li>Demography </li></ul><ul><ul><li>The statistical study of human population </li></ul></ul>
  3. 3. Population Growth <ul><li>World population is about 6.7 billion </li></ul><ul><li>Annual increase of 74-75 million </li></ul><ul><ul><li>Annual increases have been declining </li></ul></ul><ul><li>2006 UN projections </li></ul><ul><ul><li>9.2 billion in 2050 </li></ul></ul><ul><ul><li>9.4-9.5 billion by 2100 </li></ul></ul><ul><li>Future growth will occur in developing countries </li></ul>
  4. 4. Population Definitions <ul><li>Population measures are made more meaningful by rates and cohort measures </li></ul><ul><ul><li>Rates </li></ul></ul><ul><ul><ul><li>Frequency of occurrence during a specified time period </li></ul></ul></ul><ul><ul><li>Cohort </li></ul></ul><ul><ul><ul><li>Population group unified by a common characteristic, such as age </li></ul></ul></ul>
  5. 5. Birth Rates <ul><li>Annual number of live births per 1000 population </li></ul><ul><li>Influenced by age and sex structure, customs and family size expectations, population policies </li></ul><ul><ul><li>High birth rates ( ≥ 30) </li></ul></ul><ul><ul><ul><li>Characteristic of agricultural, rural countries in which a high proportion of the female population is young </li></ul></ul></ul><ul><ul><li>Low birth rates ( < 18) </li></ul></ul><ul><ul><ul><li>Characteristic of industrialized, urbanized countries </li></ul></ul></ul><ul><ul><li>Transitional birth rates (18-30) </li></ul></ul><ul><ul><ul><li>Some developing and newly industrializing countries </li></ul></ul></ul><ul><li>Subject to change </li></ul>
  6. 6. Total Fertility Rates <ul><li>Average number of children born to each woman </li></ul><ul><li>Replacement level fertility: 2.1-2.3 </li></ul><ul><li>Worldwide TFR in 2007: 2.7 </li></ul><ul><ul><li>More-developed countries: 1.6 </li></ul></ul><ul><ul><li>Less-developed countries: 2.9 </li></ul></ul><ul><li>Fertility declines in recent decades </li></ul><ul><ul><li>Dramatic declines in many less-developed countries </li></ul></ul><ul><ul><ul><li>Changing cultural values </li></ul></ul></ul><ul><ul><li>TFRs below replacement level </li></ul></ul><ul><ul><ul><li>Populations may stabilize or grow due to migration </li></ul></ul></ul>
  7. 7. Death Rates <ul><li>Annual number of deaths per 1000 population </li></ul><ul><li>In the past, varied with levels of development </li></ul><ul><ul><li>Dramatic reductions in in less-developed countries </li></ul></ul><ul><ul><ul><li>As a group, death rates now lower than in more-developed countries </li></ul></ul></ul><ul><li>Also influenced by age structure </li></ul><ul><li>Infant mortality rate </li></ul><ul><ul><li>Ratio of deaths of infants aged 1 year or under per 1000 live births </li></ul></ul><ul><ul><li>Significant declines in modern times </li></ul></ul>
  8. 8. Death Rates <ul><li>Modern medicine and sanitation have increased life expectancy </li></ul><ul><ul><li>Regional variation in benefits </li></ul></ul><ul><li>HIV/AIDS </li></ul><ul><ul><li>Sub-Saharan Africa has been hit hardest </li></ul></ul><ul><ul><ul><li>Average life expectancy has been cut </li></ul></ul></ul><ul><ul><ul><li>Food insecurity </li></ul></ul></ul>
  9. 9. Population Pyramids <ul><li>Graphic depiction of the age and sex composition of a population </li></ul><ul><li>Types of population profiles </li></ul><ul><ul><li>Rapid growth </li></ul></ul><ul><ul><li>Slow growth </li></ul></ul><ul><ul><li>Decline </li></ul></ul><ul><ul><li>Disrupted growth </li></ul></ul><ul><li>Population profile influences demands on a country’s social and economic systems </li></ul><ul><ul><li>Dependency ratio </li></ul></ul><ul><ul><ul><li>Number of economic dependents that each 100 persons in the productive years must support </li></ul></ul></ul>
  10. 10. Natural Increase and Doubling Time <ul><li>Rate of natural increase </li></ul><ul><ul><li>Birth rate minus death rate expressed as a percentage </li></ul></ul><ul><ul><li>Excludes migration </li></ul></ul><ul><li>Doubling time </li></ul><ul><ul><li>Time it takes for a population to double if current growth rate remains constant </li></ul></ul><ul><ul><ul><li>72 divided by rate of natural increase </li></ul></ul></ul><ul><ul><li>J-curve </li></ul></ul><ul><ul><ul><li>Depicts exponential (geometric) growth </li></ul></ul></ul>
  11. 11. Demographic Transition <ul><li>Model of the effect of economic development on population growth </li></ul><ul><ul><li>Stage 1: High birth and death rates </li></ul></ul><ul><ul><li>Stage 2: High birth rates and declining death rates </li></ul></ul><ul><ul><li>Stage 3: Declining birth rates and low death rates </li></ul></ul><ul><ul><li>Stage 4: Low birth and death rates </li></ul></ul><ul><ul><li>Stage 5: Death rates exceed birth rates </li></ul></ul><ul><li>Devised to describe the experience of northwest European countries </li></ul>
  12. 12. A Divided World Converging <ul><li>The population history of Europe was not relevant to all developing countries </li></ul><ul><ul><li>Many remained in the second stage </li></ul></ul><ul><li>Introduction of Western technologies of medicine and public health to developing countries </li></ul><ul><ul><li>Quickly lowered death rates </li></ul></ul><ul><li>Birth rates are largely dependent on social acceptance of fewer children </li></ul><ul><ul><li>Have fallen in some developing countries but remain high in others </li></ul></ul>
  13. 13. Demographic Equation <ul><li>Regional population change is a function of natural change and net migration </li></ul><ul><li>Population relocation </li></ul><ul><ul><li>Can relieve pressures of rapid growth </li></ul></ul><ul><li>Immigration impacts </li></ul><ul><ul><li>Demographic equation </li></ul></ul><ul><ul><li>Population structures of origin and destination </li></ul></ul><ul><ul><ul><li>Emigrant groups are skewed in favor of young singles </li></ul></ul></ul>
  14. 14. World Population Distribution <ul><li>Uneven population distribution </li></ul><ul><ul><li>Almost 90% live north of the equator </li></ul></ul><ul><ul><ul><li>2/3 of total between 20 ° and 60 ° N </li></ul></ul></ul><ul><ul><li>A large majority occupies a small part of the land </li></ul></ul><ul><ul><li>People congregate in lowland areas </li></ul></ul><ul><ul><li>Continental margins have the densest settlement </li></ul></ul><ul><li>Four clusters of population </li></ul><ul><ul><li>East Asia </li></ul></ul><ul><ul><li>South Asia </li></ul></ul><ul><ul><li>Europe </li></ul></ul><ul><ul><li>NE United States/SE Canada </li></ul></ul>
  15. 15. World Population Distribution <ul><li>Ecumene </li></ul><ul><ul><li>Permanently inhabited areas of the earth </li></ul></ul><ul><ul><li>Has been extended by technologies </li></ul></ul><ul><li>Nonecumene </li></ul><ul><ul><li>Uninhabited or very sparsely occupied zone </li></ul></ul><ul><ul><li>35% to 40% of the land surface </li></ul></ul>
  16. 16. Population Density <ul><li>The relationship between number of inhabitants and the area they occupy </li></ul><ul><li>Crude (arithmetic) density </li></ul><ul><ul><li>Number of people per unit area of land </li></ul></ul><ul><li>Physiological density </li></ul><ul><ul><li>Number of people per unit of arable land </li></ul></ul><ul><li>Agricultural density </li></ul><ul><ul><li>Number of rural residents per unit of agriculturally productive land </li></ul></ul>
  17. 17. Overpopulation <ul><li>Value judgment that the resources of an area are insufficient to sustain its present population </li></ul><ul><ul><li>Not the inevitable consequence of high density </li></ul></ul><ul><li>A continuing imbalance between numbers of people and the carrying capacity of the land </li></ul><ul><ul><li>Number of people an area can support, given the prevailing technology </li></ul></ul><ul><ul><ul><li>Related to level of economic development </li></ul></ul></ul>
  18. 18. Urbanization <ul><li>Transformation from rural to urban status </li></ul><ul><li>Rapid growth of cities in developing countries </li></ul><ul><ul><li>Nearly all world population increase between 2000 and 2030 will be in urban areas of developing countries </li></ul></ul><ul><li>Consumes a great deal of cropland </li></ul><ul><li>Problems in densely populated cities in developing countries </li></ul><ul><ul><li>Lack of housing, jobs, education, health and social services </li></ul></ul>
  19. 19. Population Data and Projections <ul><li>Population data </li></ul><ul><ul><li>Sources: United Nations, World Bank, Population Reference Bureau, national censuses </li></ul></ul><ul><ul><li>May be inaccurate </li></ul></ul><ul><li>Population projections </li></ul><ul><ul><li>Based on assumptions applied to current data </li></ul></ul><ul><ul><li>Not predictions </li></ul></ul><ul><ul><li>High, medium, and low projections may be given </li></ul></ul>
  20. 20. Population Controls <ul><li>Thomas Robert Malthus </li></ul><ul><ul><li>Unchecked population increases geometrically, food production increases arithmetically </li></ul></ul><ul><li>Equilibrium must be achieved between numbers and resources </li></ul><ul><ul><li>Overpopulation will result in a dieback </li></ul></ul><ul><ul><ul><li>J-curve converted to S-curve </li></ul></ul></ul><ul><ul><li>Homeostatic plateau </li></ul></ul><ul><ul><ul><li>Population that is equivalent to carrying capacity </li></ul></ul></ul>
  21. 21. Population Controls <ul><li>Neo-Malthusianism </li></ul><ul><ul><li>Advocacy of population control programs to improve prosperity and well-being </li></ul></ul><ul><ul><ul><li>Many countries have adopted family planning programs </li></ul></ul></ul><ul><ul><ul><ul><li>E.g., China </li></ul></ul></ul></ul><ul><li>Cornucopians </li></ul><ul><ul><li>Believe population growth is a stimulus to development </li></ul></ul>
  22. 22. Population Prospects <ul><li>Population (demographic) momentum </li></ul><ul><ul><li>Numbers of births continue to grow as fertility rates per woman decline </li></ul></ul><ul><ul><ul><li>High concentration of people in the childbearing years </li></ul></ul></ul><ul><li>Aging </li></ul><ul><ul><li>Result of transition from high to low levels of fertility and mortality </li></ul></ul><ul><ul><li>Pace is much faster in developing countries </li></ul></ul><ul><ul><li>Increasing burdens on working-age populations </li></ul></ul><ul><ul><ul><li>Potential support ratio is falling </li></ul></ul></ul>

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