Chapter 2 The World Population Distribution, Density and Growth

Introduction

The true wealth of a country lies in its people, who are the actual resources capable of utilizing other resources, shaping policies, and defining the nation. Understanding the characteristics of a country's population is therefore crucial.

Significance Of Population Study

Studying population involves knowing fundamental details about the people, such as the number of men and women, birth and death rates, where they live (urban vs. rural), their literacy levels, and their occupations. These factors provide insights into the social, economic, and historical context of a region.

At the start of the 21st century, the global population exceeded 6 billion people. This chapter explores the patterns of how these people are spread across the Earth's surface (distribution) and how crowded different areas are (density).

Patterns Of Population Distribution In The World

Population distribution describes how people are spaced over the Earth's surface. It is notably uneven. A striking fact is that roughly 90% of the world's population lives on only about 10% of the total land area.

The distribution is highly concentrated. Just 10 countries account for approximately 60% of the global population. Of these ten most populous nations, six are located in Asia, highlighting the high concentration of people on this continent.

Density Of Population

The density of population is a key measure that helps understand the relationship between the number of people and the land area they occupy. It indicates the degree of crowding in a region.

Calculation Of Population Density

Population density is calculated by dividing the total population of a region by its total land area. It is typically expressed as the number of persons per square kilometre (or square mile).

$ \text{Density of Population} = \frac{\text{Population}}{\text{Area}} $

Answer:

High density often indicates favourable conditions for human settlement and economic activities in that area.

Factors Influencing The Distribution Of Population

Various factors influence why people choose to live in certain areas, leading to uneven population distribution and varying densities across the globe. These factors can be broadly grouped into geographical, economic, and social/cultural categories.

Geographical Factors

• Availability of Water: Water is fundamental for life and essential for agriculture, industry, and other uses. Areas with easily accessible fresh water sources, such as river valleys, tend to be densely populated.
• Landforms: People prefer flat plains and gentle slopes which are conducive to agriculture, building infrastructure (roads, railways), and industrial development. Mountainous and hilly regions often pose difficulties for transportation and development, resulting in sparser populations. For example, the densely populated Ganga plains contrast with the sparsely populated Himalayas.
• Climate: Areas with comfortable climates, avoiding extremes of heat, cold, or excessive rainfall, attract more people. Harsh or unpredictable climates are generally less favourable for human habitation. The pleasant climate of Mediterranean regions historically attracted early settlements.
• Soils: Fertile soils are vital for productive agriculture. Areas with fertile loamy soils can support intensive farming and therefore tend to have higher population densities. Conversely, regions with poor or infertile soils are often thinly populated.

Economic Factors

• Minerals: Regions rich in mineral deposits often develop mining and related industries, creating employment opportunities. This attracts both skilled and unskilled labor, leading to higher population densities in mining areas (e.g., the Katanga Zambia copper belt in Africa).
• Urbanisation: Cities offer numerous advantages like better job prospects, superior educational and healthcare facilities, improved transport and communication networks, and a wider range of amenities. The attraction of urban life drives migration from rural to urban areas, causing cities to grow rapidly and become densely populated centres.
• Industrialisation: Industrial belts are significant drivers of population concentration. Industries provide direct factory jobs and also generate demand for workers in related services like transport, banking, retail, healthcare, and education. This influx of diverse workers makes industrial regions highly populated (e.g., the Kobe-Osaka region in Japan).

Social and Cultural Factors

• Some places attract people due to their religious or cultural significance, becoming centers of population.
• Conversely, areas experiencing social and political unrest, conflicts, or discrimination often see people moving away.
• Governments can also influence population distribution through policies, such as offering incentives to settle in sparsely populated regions or encouraging relocation from overcrowded areas.

Population Growth

Population growth or population change refers to the variation in the number of inhabitants in a specific area over a given period. This change can be an increase (positive growth) or a decrease (negative growth).

Population change can be measured in absolute numbers (the total difference in population between two points in time) or as a percentage (the growth rate).

The rate and pattern of population change in a region provide valuable insights into its economic development, social progress, and historical context.

Here are some key concepts related to population change:

• Growth of Population: The absolute change in population size of a territory between two specific points in time.
• Growth Rate of Population: The change in population expressed as a percentage of the population at the start of the period.
• Natural Growth of Population: The population change resulting solely from the difference between the number of births and deaths in a region over a period. $ \text{Natural Growth} = \text{Births} - \text{Deaths} $
• Actual Growth of Population: The total population change, considering births, deaths, and migration (both in-migration and out-migration). $ \text{Actual Growth} = (\text{Births} - \text{Deaths}) + (\text{In Migration} - \text{Out Migration}) $
• Positive Growth of Population: Occurs when the number of births exceeds the number of deaths, or when there is net in-migration (more people moving in than moving out).
• Negative Growth of Population: Occurs when the number of deaths exceeds the number of births, or when there is net out-migration (more people moving out than moving in), leading to a decrease in population size.

Components Of Population Change

The size of a population changes due to three main components: births, deaths, and migration.

• Births: The number of live births adds to the population. The Crude Birth Rate (CBR) is a common measure, expressed as the number of live births per thousand people in a given year.

  $ \text{CBR} = \frac{\text{Number of live births during the year}}{\text{Estimated mid-year population}} \times 1000 $

• Deaths: The number of deaths removes individuals from the population. The Crude Death Rate (CDR) is a simple measure of mortality, expressed as the number of deaths per thousand people in a given year.

  $ \text{CDR} = \frac{\text{Number of deaths}}{\text{Estimated mid-year population}} \times 1000 $

  Mortality rates are influenced by factors like a region's age structure, social development, and economic conditions.

• Migration: The movement of people from one place to another also changes population size.

Migration

Migration involves movement from a Place of Origin to a Place of Destination. The population decreases at the place of origin and increases at the place of destination. Migration is often seen as a response to imbalances between population and resources, or as an effort to seek better opportunities.

Migration can be categorized by duration (permanent, temporary, seasonal) and origin/destination (rural-to-rural, rural-to-urban, urban-to-urban, urban-to-rural).

• Immigration: People who move into a new place.
• Emigration: People who move out of a place.

The decision to migrate is influenced by factors that make the origin less attractive (Push Factors) and the destination more attractive (Pull Factors):

Historically, the world population has experienced significant growth, increasing more than tenfold over the past 500 years, with a rapid acceleration in the 20th century alone.

DEMOGRAPHIC TRANSITION THEORY

The Demographic Transition Theory is a model that describes population change over time as a society moves from pre-industrial to an industrialized economic system. It suggests that population of any region evolves through distinct stages, collectively known as the demographic cycle, shifting from high birth rates and high death rates to low birth rates and low death rates as literacy, urbanization, and technological advancement increase.

The theory is often illustrated with a three-staged model (though some models use five stages):

• Stage I (High Fluctuating): Characterized by high fertility and high mortality. Population growth is slow and fluctuates. High birth rates compensate for high death rates caused by factors like epidemics and unreliable food supplies. Most people are engaged in agriculture, valuing large families for labor. Life expectancy is low, literacy is limited, and technology is primitive. Historically, all countries were in this stage around 200 years ago. Examples might include some isolated tribes today.
• Stage II (Expanding): This stage begins with high fertility but sees a significant decline in mortality. Improvements in sanitation, health care, and nutrition lead to a rapid fall in death rates. Birth rates remain high initially, resulting in a wide gap between births and deaths and consequently, rapid population growth. As society progresses, fertility rates start to fall gradually. Countries like Peru, Sri Lanka, and Kenya are considered to be in this stage.
• Stage III (Low Fluctuating): In this final stage (in the three-stage model), both fertility and mortality decline considerably and converge. The birth rate falls as the society becomes urbanized, literate, and industrial. People gain technical knowledge and deliberately control family size, often due to changing social norms, increased cost of raising children in urban areas, and better access to family planning. Population growth becomes either very slow or stable. Countries like Canada, Japan, and the USA are in this stage.

The Demographic Transition Theory highlights the adaptability of human populations in adjusting their fertility behavior in response to socio-economic and technological changes. Different countries across the world are currently in various stages of this transition.

POPULATION CONTROL MEASURES

Controlling rapid population growth is crucial for the sustainable use of resources and overall development. Measures aimed at limiting or influencing population growth include:

Family Planning And Awareness

Family planning involves individuals and couples deciding freely and responsibly on the number and spacing of their children. Access to family planning services and information is a key factor in lowering fertility rates and improving maternal and child health.

Government efforts can include public awareness campaigns (propaganda), providing free or subsidized access to contraceptives, and potentially implementing policies like tax disincentives for larger families.

Malthusian Theory

Economist Thomas Malthus proposed a theory in 1798 suggesting that human populations tend to grow exponentially (geometrically), while food supply increases only linearly (arithmetically). He predicted that population growth would eventually outstrip the available food resources, leading to a "population crash" caused by natural checks like famine, disease, and war.

Malthus argued for "preventive checks" (like moral restraint or delaying marriage) as preferable ways to control population growth compared to these "physical checks". His theory underscores the potential conflict between population growth and resource availability, highlighting the importance of managing population increase for long-term sustainability.