Population Distribution and Density

Introduction to Population Distribution

  • Earth's human population is unevenly distributed.

  • Some live in isolation, others are densely packed.

  • Understanding these variations is crucial.

  • Two basic factors explain population distribution: physical and human.

Factors Influencing Population Distribution

1. Physical Factors

  • Humans depend on the environment for survival; environmental features determine settlement.

Climate

  • Harsh climates deter high population densities.

  • Too wet, cold, or dry conditions limit settlement.

  • Australia: Most people live near the coast (temperate climate), while the center is sparsely populated due to dryness and heat.

  • Mid-latitudes (30 to 60 degrees from the equator) are preferred due to milder temperatures and decent precipitation. Humans love to live in the Mid Latitudes

Landforms

  • Lowland areas are favored because they are easier to build on and farm.

  • Mountainous areas tend to be sparsely populated due to challenges like cold temperatures, minimal food, and lack of breathable air.

  • Exceptions exist near the Equator, where mountainous regions can be highly populated due to cooler, more temperate climates.

Water Bodies

  • Historically, settlements gather around water bodies (rivers, oceans, lakes).

  • Importance of water bodies:

    • Drinking water.

    • Water for crops.

    • Facilitates travel and trade.

2. Human Factors

Culture

  • Cultural attachment to a place influences settlement.

  • Example: Jews and Muslims have cultural ties to the land of Israel and Palestine.

Economics

  • People settle where they can make a living (resources and jobs).

  • Economics drives migration patterns.

    • African slave trade: Economic incentives moved enslaved Africans to the Americas starting in the 15th century.

    • 19th-century US immigration: Jobless Europeans migrated to America for work.

History

  • Past population distributions influence present distributions.

    • Over half of Black Americans live in the South due to the history of slavery.

    • Almost half of Asian Americans live in the West because their ancestors migrated and settled there.

Politics

  • Political factors influence migration.

    • 19th-century European immigrants sought refuge in America from tyranny.

    • Forced displacement: In 1975, the Khmer Rouge regime forced millions of Cambodians from Phnom Penh into rural areas.

Population Density

  • Population density: Measure of how many people occupy a given unit of land.

  • Distinct from population distribution (where people live) versus population density (how many people live there).

Calculating Population Density

  • Geographers use three methods to calculate Population Density.

Arithmetic Density:

  • Arithmetic density = Total population / Total land area.

    • Arithmetic Density = \frac{Total Population}{Total Land Area}

*It can be misleading because it assumes even distribution.

*   Example: Taiwan's arithmetic density might suggest even distribution, which is not the case.
Physiological Density:

  • Physiological density = Total population / Total amount of arable land.

    • Physiological Density = \frac{Total Population}{Total Arable Land}

  • Arable land: Land that can be used for agriculture.

  • Indicates whether a population can feed itself.