Chapter 3: Population Distribution and Composition

Chapter 3 Outline

3.1 Where People Live

  • Population Distribution: Study of where people live and its patterns.
    • Global Population reached 7.8 billion in December 2019.
    • Two-thirds of the population in East Asia, South Asia, Southeast Asia, and Western Europe.
    • Population growth peaked in the second half of the 20th century.
  • Importance of Studying Population:
    • Analysis of factors driving population growth and distribution.
    • Understanding how physical, environmental, and human factors affect population movement.

Patterns of Population Distribution

  • Uniform Patterns: Even distribution across an area.
  • Clustered Distribution: Higher concentration in specific areas.
  • Linear Distribution: Development along a line.
  • Random Distribution: No specific arrangement.

Physical and Environmental Factors

  • Survival Factors: People settle where survival is easier—low elevations, temperate climates, and proximity to water.
    • Majority live below 1,500 ft elevation.
  • Climate: Influences population distribution through long-term weather patterns. Areas with moderate temperatures and adequate precipitation have higher populations.
  • Landforms: Natural features affecting settlement patterns, e.g., agricultural communities near rivers.
  • Water Accessibility: Necessary for survival and a key distribution factor; e.g., population concentrated along the Yangtze River in China.

Human Factors affecting Population Distribution

  • Economic Factors:
    • Migration driven by economic opportunities (e.g., European migration to Americas).
    • Availability of natural resources can attract populations.
  • Political Factors:
    • Migration often occurs due to dissatisfaction with government (e.g., Cambodia's Khmer Rouge).
  • Cultural Factors:
    • Sense of belonging, safety, transportation access, and housing.
    • Historical migration affects current population distribution.

Measuring Population Density

  • Population Density: Number of people in a unit of land. Higher density often correlates with resource availability.
    • Arithmetic Density: Total population ÷ total land area.
    • Physiological Density: Total population ÷ arable land area; reflects conditions for agriculture.
    • Agricultural Density: Number of farmers per unit of arable land; reveals economic structures in countries.

3.2 Consequences of Population Distribution

  • Impact on Society:
    • Issues like crowding, unequal access to services, and environmental impacts influence quality of life.
  • Impact on Environment:
    • Greater populations lead to pressure on resources (arable land, water).
    • Carrying capacity: The maximum population an environment can sustain without degradation.

Case Study: Examples of Population Distribution

  • Egypt: High physiological density (9,182 people per mile²).
  • Canada: Low physiological density (194 people per mile²). Both have large uninhabitable areas.

3.3 Population Composition

  • Dependency Ratio: Number of dependents (ages
  • Sex Ratio: Ratio of men to women in a population; influenced by cultural factors.

3.4 Measuring Growth and Decline

  • Fertility Rates: Birth rate measurements affecting population growth (e.g., Crude Birth Rate and Total Fertility Rate).
  • Mortality Rates: Death rates impact population change (e.g., Crude Death Rate and Infant Mortality Rate).
  • Population Pyramids: Visual tools to interpret population structure, showing growth trends and implications.

Additional Notes

  • Comparisons of birth and death rates help define population changes.
  • Historical migrations and governmental policies have lasting effects on population distribution.
  • Understanding dynamics of population density aids in resource management and urban planning.