Heimler - topic 2.1Population Distribution and Density Flashcards

Population Distribution

  • Definition: Patterns of human habitation across the Earth's surface, answering why people live where they do.
  • Uneven Distribution: 8 billion people live on only 5% of the Earth's surface.
  • Ecumen: Habitable portion of the Earth's surface.
  • Population Clusters: Approximately two-thirds of the world's population resides in South Asia, Southeast Asia, East Asia, and Europe.

Factors Influencing Population Distribution

Physical Factors
  • Climate:
    • Mid-Latitudes: Between 30 and 60 degrees from the equator are preferred due to milder climates and sufficient precipitation.
  • Landforms:
    • Lowland Areas: Preferred for building and farming.
    • Mountainous Regions Near Equator: Can be highly populated due to cooler temperatures at higher elevations.
  • Water:
    • Proximity to Water: Clusters near rivers and coastal areas for drinking water and trade routes.
    • Eurasia, Australia, and South America: Populations concentrated around coastal areas.
Human Factors
  • Culture:
    • Cultural Amenities: Higher concentrations where education and healthcare are accessible.
  • Economics:
    • Job Availability: People settle where they can make a living, with abundant resources and jobs.
  • History:
    • Historical Patterns: Past population distributions influence present distributions (e.g., major cities like Paris, Beijing, New York).
  • Politics:
    • Political Policies: Influence movement; leaders' decisions can alter distribution (e.g., Soviet Union moving Russians to Siberia).
Scale of Analysis
  • Global Scale: Climate and access to water.
  • Local Scale: Landforms (e.g., Rocky Mountains).

Population Density

  • Definition: Measure of how many people occupy a unit of land.
  • Distinction: Distribution shows where populations are, density shows how many.
  • Example: One square mile with one person has a density of one person per square mile; with 10 people, the density is 10 people per square mile.
  • Jeff Gibson's Example:
    • Everyone on Earth could live in a city the size of Texas if density is managed.
    • Houston: ~3,500 people per square mile.
    • New York: ~29,000 people per square mile.
    • All 8 billion people could live in a Texas-sized city at New York's density.

Calculations of Population Density

Arithmetic Density
  • Formula: Total Population/Total Land Area\text{Total Population} / \text{Total Land Area}
  • Example: 10 people in one square mile equals 10 people per square mile.
  • Shortcoming: Assumes all land is equally habitable, which is often untrue. For example, Taiwan's population is not evenly distributed.
Physiological Density
  • Definition: Total population divided by total arable land.
  • Arable Land: Land suitable for agriculture.
  • Formula: Total Population/Total Arable Land\text{Total Population} / \text{Total Arable Land}
  • Significance: Indicates how well a population can feed itself.
    • Example: If half the land is arable, 10 people / 0.5 square mile = 20 people per square mile.
    • If a quarter is arable, 10 people / 0.25 square mile = 40 people per square mile.
  • Interpretation: Higher density means more pressure on farmland; lower density means land can likely produce enough food.
Agricultural Density
  • Definition: Total farmers divided by total arable land.
  • Formula: Total Farmers/Total Arable Land\text{Total Farmers} / \text{Total Arable Land}
  • Significance: Reveals labor intensity in agriculture.
    • Lower Number: Indicates fewer farmers, implying more mechanization.
    • Higher Number: Indicates many subsistence farmers growing only what they need.
Importance of Calculations
  • Each calculation helps understand human impact on environments.