The World Population Distribution, Density and GrowthClass 12 Fundamentals of Human Geography Notes

The World Population: An Introduction

The people of a country are its most valuable asset, or its real wealth. They are the ones who use a country's resources and shape its policies. To understand a country, we must first understand its people—how many there are, where they live, and how their numbers change over time.

At the beginning of the 21st century, the world's population exceeded 6 billion people. However, these people are not spread out evenly across the globe. As geographer George B. Cressey noted about Asia, "Asia has many places where people are few and few place where people are very many." This statement is true for the entire world.

Patterns of Population Distribution in the World

Population distribution refers to the way people are spaced over the Earth's surface. This distribution is highly uneven.

• A staggering 90 percent of the world's population lives on only about 10 percent of its land area.
• The 10 most populous countries in the world account for about 60 percent of the total global population.
• Of these 10 countries, six are located in Asia.

Understanding these patterns helps us learn about the demographic characteristics of any region.

Density of Population

To measure how crowded a place is, we use the concept of density of population. This is the ratio between the number of people and the size of the land they live on. It is usually measured in persons per square kilometer.

The formula to calculate population density is: Density of Population = Population / Area

Factors Influencing the Distribution of Population

People choose to live in certain areas for specific reasons. These reasons can be grouped into three main categories: geographical, economic, and social/cultural.

I. Geographical Factors

These factors relate to the physical environment.

• Availability of water: Water is essential for drinking, cooking, farming, and industry. Because of this, river valleys are some of the most densely populated areas in the world. People prefer to live where fresh water is easily accessible.
• Landforms: People generally prefer to live on flat plains and gentle slopes. These areas are ideal for growing crops, building roads, and establishing industries. In contrast, mountainous and hilly areas make transportation, agriculture, and industrial development difficult, so they tend to be less populated. [!example] The Ganga plains in India are very densely populated, while the Himalayan mountain zones are sparsely populated.
• Climate: Extreme climates, like very hot or cold deserts, are uncomfortable and discourage settlement. People are attracted to areas with a comfortable climate that doesn't have much seasonal variation. Regions with very heavy rainfall or harsh conditions also have low populations. [!example] The Mediterranean regions have been popular places to live since ancient times due to their pleasant climate.
• Soils: Fertile, loamy soils are crucial for agriculture. Areas with such soils can support intensive farming and, therefore, more people. Regions with poor soil quality tend to be thinly populated.

II. Economic Factors

These factors relate to economic opportunities and development.

• Minerals: Areas rich in mineral deposits attract industries. Mining and industrial activities create jobs for skilled and semi-skilled workers, causing these areas to become densely populated. The Katanga Zambia copper belt in Africa is a good example.
• Urbanisation: Cities attract people because they offer better employment opportunities, educational and medical facilities, and advanced transport and communication. The amenities and attractions of city life lead to rural to urban migration, causing cities to grow. Mega cities around the world continue to attract a large number of migrants.
• Industrialisation: Industrial belts provide a wide range of job opportunities, not just for factory workers but also for transport operators, shopkeepers, teachers, and doctors. This attracts a large number of people, leading to high population density. [!example] The Kobe-Osaka region of Japan is thickly populated due to the presence of many industries.

III. Social and Cultural Factors

These factors relate to the social environment and cultural significance of a place.

• Some places attract more people because they have religious or cultural importance.
• Conversely, people tend to move away from areas with social and political unrest.
• Sometimes, governments offer incentives to encourage people to live in sparsely populated areas or to move away from overcrowded ones.

Population Growth

Population growth, or population change, is the change in the number of people living in a territory over a specific period. This change can be positive (an increase) or negative (a decrease) and can be measured in absolute numbers or as a percentage.

Some Basic Concepts of Population Geography

• Growth of Population: The change in population between two points in time, expressed as an absolute number. [!example] If India's population was 102.70 crore in 2001 and 121.02 crore in 2011, the growth of population was 18.15 crore.
• Growth Rate of Population: The change in population expressed as a percentage.
• Natural Growth of Population: The population increase calculated by subtracting deaths from births. Natural Growth = Births – Deaths.
• Actual Growth of Population: This considers migration as well. Actual Growth = Births – Deaths + In-Migration – Out-Migration.
• Positive Growth of Population: Occurs when the birth rate is higher than the death rate, or when people migrate into the region.
• Negative Growth of Population: Occurs when the death rate is higher than the birth rate, or when people migrate out of the region.

Components of Population Change

There are three main components that cause population to change: births, deaths, and migration.

Births and Deaths

The Crude Birth Rate (CBR) is the number of live births in a year for every thousand people in the population.

• CBR = (Live Births during the year / Mid-year population) x 1000

The Crude Death Rate (CDR) is the number of deaths in a year for every thousand people in the population.

• CDR = (Number of deaths / Mid-year population) x 1000

Population growth happens not only when birth rates increase but also when death rates decrease. Mortality rates are influenced by a region's demographic structure, social advancement, and level of economic development.

Migration

Migration is the movement of people from one place to another.

• The place people move from is the Place of Origin.
• The place they move to is the Place of Destination.

Migration causes the population to decrease in the place of origin and increase in the place of destination. It can be permanent, temporary, or seasonal. People can move from rural to urban areas, urban to rural areas, or between similar types of areas.

• Immigration: When migrants move into a new place. These people are called Immigrants.
• Emigration: When migrants move out of a place. These people are called Emigrants.

Push and Pull Factors of Migration

People migrate for a better economic and social life, influenced by two sets of factors:

• Push factors make the place of origin seem less attractive. These include:
  • Unemployment
  • Poor living conditions
  • Political turmoil
  • Unpleasant climate
  • Natural disasters, epidemics, and socio-economic backwardness
• Pull factors make the place of destination seem more attractive. These include:
  • Better job opportunities and living conditions
  • Peace and stability
  • Security of life and property
  • Pleasant climate

Trends in Population Growth

The human population has grown tremendously over time.

• In the past 500 years, the human population has increased more than ten times.
• In the 20th century alone, the population quadrupled.

Demographic Transition

The Demographic Transition Theory is a model used to describe and predict the future population of an area. It states that as a society progresses from a rural, agrarian, and illiterate state to an urban, industrial, and literate one, its population shifts from having high birth and death rates to low birth and death rates. This process occurs in stages, collectively known as the demographic cycle.

The Three Stages of Demographic Transition

1. Stage One: High Fertility and High Mortality

   • In this stage, birth rates are high because people have more children to compensate for the high death rates caused by epidemics and unreliable food supplies.
   • Population growth is slow.
   • Most people work in agriculture, where large families are considered an asset.
   • Life expectancy is low, and technology levels are low. Two hundred years ago, all countries were in this stage.

2. Stage Two: High Fertility and Reduced Mortality

   • Fertility remains high at the beginning but starts to decline over time.
   • Mortality rates fall due to improvements in sanitation and health conditions.
   • Because the birth rate is still much higher than the death rate, the net addition to the population is very high, leading to rapid population growth.

3. Stage Three: Low Fertility and Low Mortality

   • In the final stage, both birth and death rates decline significantly.
   • The population becomes stable or grows very slowly.
   • The society is urbanised and literate, with high levels of technology. People deliberately control family size.

This model shows that human beings are flexible and can adjust their fertility based on their societal conditions. Today, different countries are at different stages of this demographic transition.

Population Control Measures

Family planning refers to the spacing or prevention of births. Providing access to family planning services is a key factor in limiting population growth and improving women's health.

Methods to help control population include:

• Propaganda and awareness campaigns.
• Free availability of contraceptives.
• Tax disincentives for large families.

In 1798, Thomas Malthus proposed a theory that the population would increase much faster than the food supply. He warned that this would lead to a "population crash" caused by famine, disease, and war. He argued that preventive checks (like family planning) are better than these physical checks. To ensure the sustainability of our resources, it is crucial for the world to control rapid population increase.