The World Population: Distribution, Density and Growth | CBSE Class 12 Geography Notes

This note covers world population distribution and density, geographical, economic, social and cultural influences, population growth, birth and death rates, migration, push and pull factors, demographic transition, family planning and population control.

How is the world's population distributed?

Population distribution means the way people are spaced over the earth's surface. The world's population is unevenly distributed: some places contain many people, while others have few inhabitants. Distribution describes this spatial pattern.

People are a country's real wealth. They use its other resources and decide its policies. Studying population therefore involves understanding both the number of people and the places in which they live.

What does uneven distribution mean?

Broadly, 90 per cent of the world population lives in about 10 per cent of its land area. This concentration shows why a description of the world's total population alone cannot explain where people live.

The 10 most populous countries contribute about 60 per cent of the world's population. Of these 10 countries, 6 are located in Asia. Patterns of distribution and density help explain the demographic characteristics of an area.

At the beginning of the 21st century, the world recorded a population of over 6 billion. This is a figure for that period, rather than an undated population total.

The horizontal bar chart labels China, India, U.S.A., Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia and Mexico. Its horizontal axis shows population in million. China and India have the longest bars.

See Fig. 2.1 in your NCERT textbook

The graph presents population totals for individual countries. The broader pattern of uneven distribution raises a further question: which environmental conditions, employment opportunities and social circumstances encourage people to live in particular places?

What is population density and how is it calculated?

Definition: Population density is the ratio between the number of people and the size of the land they occupy. It is usually measured in persons per sq km.

Each unit of land has a limited capacity to support the people living on it. Density relates population to land area, allowing the number of inhabitants to be considered alongside the space available to them.

How does the Region X calculation work?

Density of Population = Population / Area

Region X has an area of 100 sq km and a population of 1,50,000 persons. Dividing its population by its area gives a density of 1,500 person/sq km.

The calculation expresses the relationship between the region's total population and its total area. The result is a number of people per unit of land, rather than another statement of the population total.

How does density differ from distribution?

Distribution asks how people are spaced over the earth's surface. Density expresses the population-to-area ratio. These ideas are related, but their definitions answer different questions about the population of a region.

A discussion of densely populated places therefore needs both a measure of concentration and an explanation of the factors attracting people. Water, landforms, climate, soils and economic opportunities help explain why density differs between areas.

How do geographical factors influence population distribution?

The main geographical factors are availability of water, landforms, climate and soils. They influence the conditions for human habitation and for activities such as agriculture, transport and industry.

Why is access to water important?

Water is the most important factor for life. People prefer areas where fresh water is easily available. It is needed for drinking, bathing and cooking, as well as for cattle, crops, industries and navigation.

Because water supports these uses, river valleys are among the most densely populated areas of the world. The connection involves both everyday household needs and the activities through which people obtain their livelihoods.

Case study: Why do the Ganga plains and Himalayan mountain zones differ?

The Ganga plains are among the most densely populated areas of the world, while mountain zones in the Himalayas are scarcely populated. This contrast illustrates the influence of landforms on settlement.

People prefer flat plains and gentle slopes because they favour crop production and the building of roads and industries. Mountainous and hilly areas hinder transport networks and hence initially do not favour agricultural and industrial development. These areas tend to be less populated.

How do climate and soils affect settlement?

Extreme climates, such as very hot or cold deserts, are uncomfortable for human habitation. Areas with a comfortable climate and little seasonal variation attract more people. Areas with very heavy rainfall or extreme and harsh climates have low population.

Mediterranean regions were inhabited from early periods in history because of their pleasant climate. This example links the attraction of a region to climatic conditions rather than to its population total alone.

Fertile soils matter for agriculture and allied activities. Areas with fertile loamy soils have more people living on them because these soils can support intensive agriculture.

How do economic, social and cultural factors attract people?

Economic factors influence distribution through employment, services and opportunities. Mineral deposits, urbanisation and industrialisation attract people in different but related ways. Social and cultural conditions also affect whether places attract people or encourage them to move away.

Why do minerals and cities draw population?

Areas with mineral deposits attract industries. Mining and industrial activities generate employment, bringing skilled and semi-skilled workers to these areas and making them densely populated. The Katanga Zambia copper belt in Africa is an example.

Cities offer better employment opportunities, educational and medical facilities, and better transport and communication. Good civic amenities and the attraction of city life draw people towards them.

This movement leads to rural to urban migration, and cities grow in size. Mega cities continue to attract large numbers of migrants every year. Yet city life can be very taxing, so its attraction does not mean every aspect of urban living is pleasant.

Case study: Why is the Kobe-Osaka region thickly populated?

The Kobe-Osaka region of Japan is thickly populated because of the presence of a number of industries. Industrial belts attract large numbers of people by providing employment opportunities.

These opportunities extend beyond factory workers. They also include transport operators, shopkeepers, bank employees, doctors, teachers and other service providers. The population attracted by industrialisation therefore includes people doing several kinds of work.

1. Mineral deposits attract industries to an area.
2. Mining and industrial activities generate employment opportunities.
3. Skilled and semi-skilled workers move to the area for these opportunities.
4. The movement of workers contributes to the area's dense population.

What role do social and cultural conditions play?

Some places attract more people because they have religious or cultural significance. People tend to move away from places affected by social and political unrest.

Many a times, governments offer incentives for people to live in sparsely populated areas or to move away from overcrowded places. Such measures influence where people settle, alongside physical conditions and employment opportunities.

What is population growth and how do its forms differ?

Population growth, or population change, is the change in the number of inhabitants of a territory during a specific period. It may be positive or negative and can be expressed as an absolute number or as a percentage.

Population change is an important indicator of a region's economic development, social upliftment, and historical and cultural background. The growth rate of population is population change expressed in percentage.

How do natural growth and actual growth differ?

Natural growth is the increase obtained from the difference between births and deaths in a region between two points of time. Actual growth also includes people moving into and out of the region.

Natural Growth = Births − Deaths

Actual Growth = Births − Deaths + In Migration − Out Migration

When is growth positive or negative?

Positive growth occurs when the birth rate exceeds the death rate between two points of time or when people from other countries migrate permanently to a region.

Negative growth means that population decreases between two points of time. It occurs when the birth rate falls below the death rate or people migrate to other countries.

Note: Population growth does not necessarily mean an increase. The term population change includes both positive and negative changes over a specified period.

How do births and deaths affect population change?

The three components of population change are births, deaths and migration. Birth and death rates express vital events in relation to population, while migration accounts for movement between places.

How is the crude birth rate measured?

The crude birth rate, or CBR, is the number of live births in a year per thousand of population. Its calculation uses the estimated mid-year population of the area.

CBR = (B / P) × 1000

Here, B represents live births during the year, and P represents the estimated mid-year population of the area. The numerator is live births, rather than the area's entire population.

How is the crude death rate measured?

The crude death rate, or CDR, is the number of deaths in a particular year per thousand of population in a particular region. It is a simple way to measure mortality.

CDR = (D / P) × 1000

Here, D represents the number of deaths, and P is the estimated mid-year population of that year. Both crude rates relate events during a year to a population denominator.

Why does a falling death rate matter?

Population growth occurs not only through an increasing birth rate but also through a decreasing death rate. Births and deaths must therefore be considered together when explaining natural population change.

By and large, mortality rates are affected by a region's demographic structure, social advancement and level of economic development. These influences connect death rates with the wider characteristics of the population and its conditions of life.

What is migration and how does it change population size?

Migration changes population size through movement from one place to another. The place people leave is their place of origin. The place to which they move is their place of destination.

The place of origin shows a decrease in population, while the place of destination shows an increase. Migration may be interpreted as a spontaneous effort to achieve a better balance between population and resources.

How do immigration and emigration differ?

Migrants moving into a new place are immigrants. Migrants moving out of a place are emigrants. The same person is therefore both an immigrant and an emigrant when considered from the destination and origin respectively.

What forms can migration take?

Migration may be permanent, temporary or seasonal. Its duration and its direction are different aspects of the movement. The rural or urban character of the origin and destination identifies the following directions:

• Rural to rural: movement from one rural area to another rural area.
• Rural to urban: movement from a rural area to an urban area.
• Urban to urban: movement from one urban area to another urban area.
• Urban to rural: movement from an urban area to a rural area.

People migrate for a better economic and social life. To explain a movement, consider both the circumstances encouraging people to leave their origin and the circumstances making the destination attractive.

How do push and pull factors influence migration?

Push factors make the place of origin seem less attractive. Pull factors make the destination seem more attractive than the origin. Together, these concepts explain the pressures and attractions associated with migration.

Which conditions act as push factors?

Reasons include unemployment, poor living conditions, political turmoil, unpleasant climate, natural disasters, epidemics and socio-economic backwardness. These conditions make the place people currently occupy seem less attractive.

The list includes economic, political, environmental and health-related circumstances. It therefore connects migration with several aspects of life at the origin, rather than with employment alone.

Which conditions act as pull factors?

Reasons include better job opportunities and living conditions, peace and stability, security of life and property, and pleasant climate. These conditions make the destination seem more attractive than the origin.

The distinction depends on which place the condition concerns. Poor conditions at the origin push people away; attractive conditions at the destination pull them towards it. Both sets of factors relate to the search for a better economic and social life.

Urbanisation illustrates the attraction of a destination. Employment, educational and medical facilities, transport, communication and civic amenities draw people to cities, contributing to rural to urban migration and the growth of cities.

How does demographic transition explain changing population growth?

Demographic transition theory can describe and predict the future population of an area. It explains a change from high births and high deaths to low births and low deaths as society moves from rural, agrarian and illiterate to urban, industrial and literate.

These changes occur in stages collectively called the demographic cycle. The model has three stages. The relationship between fertility and mortality changes across them, producing different patterns of population growth.

What happens in the first stage?

The first stage has high fertility and high mortality. People reproduce more to compensate for deaths caused by epidemics and variable food supply. Despite high fertility, population growth is slow.

Most people are engaged in agriculture, where large families are an asset. Life expectancy is low, people are mostly illiterate, and technology is at a low level. Two hundred years ago, all the countries of the world were in this stage.

Why is population addition high in the second stage?

Fertility remains high at the beginning of the second stage but declines with time. Meanwhile, improvements in sanitation and health conditions reduce mortality. The gap between fertility and mortality produces a high net addition to population.

The crucial relationship is the difference between births and deaths. Declining mortality can increase population growth while fertility is still high, even though fertility itself later falls.

What characterises the last stage?

Both fertility and mortality decline considerably. Population is either stable or grows slowly. It becomes urbanised and literate, has high technical know-how, and deliberately controls family size.

The transition shows that human beings are extremely flexible and able to adjust their fertility. Different countries are at different stages of demographic transition.

Birth-rate and death-rate curves are plotted against time. Stages I, II and III are labelled High Fluctuating, Expanding and Low Fluctuating. The hatched gap between the curves is labelled Natural Increase in Population.

See Fig. 2.2 in your NCERT textbook

The drawing makes the widening and narrowing gap between the rates visible. Its birth-rate curve remains high after the death-rate curve begins falling, before both reach low levels in the final stage.

How can family planning help control population growth?

Family planning means spacing or preventing the birth of children. Access to family planning services is a significant factor in limiting population growth and improving women's health.

Which population control measures are identified?

Propaganda, free availability of contraceptives and tax disincentives for large families are some measures that can help population control. Their stated purpose is to help limit rapid population increase.

The connection with women's health is part of the importance of access to family planning services. Family planning concerns the spacing or prevention of births, while demographic transition describes wider changes in fertility, mortality and society.

What did Thomas Malthus argue?

Thomas Malthus, in his theory of 1798, stated that the number of people would increase faster than the food supply. Further increase would result in a population crash caused by famine, disease and war.

Preventive checks are better than physical checks. Controlling rapid population increase is necessary for the sustainability of resources. The discussion connects population control with the relationship between people and the resources supporting them.

Note: Family planning includes spacing births as well as preventing them. Its importance includes both limiting population growth and improving women's health.

Glossary

• Population distribution — The way people are spaced over the earth's surface.
• Population density — The ratio of population to land area, usually measured in persons per sq km.
• Population growth — Change in the number of inhabitants of a territory during a specific period.
• Growth rate — The change in a population expressed in terms of percentage.
• Natural growth — Population increase obtained from the difference between births and deaths between two points of time.
• Actual growth — Births minus deaths, plus in-migration and minus out-migration, in a region.
• Crude birth rate — The number of live births in a year per thousand of population.
• Crude death rate — The number of deaths in a particular year per thousand of population in a region.
• Immigrants — Migrants who move into a new place, viewed from their destination.
• Emigrants — Migrants who move out of a place, viewed from their origin.
• Push factors — Conditions that make the place of origin seem less attractive to people.
• Pull factors — Conditions that make the destination seem more attractive than the place of origin.
• Demographic transition — The staged change from high births and deaths to low births and deaths as society becomes urban, industrial and literate.
• Demographic cycle — The stages through which the changes of demographic transition occur.
• Family planning — The spacing or preventing of the birth of children.

Common errors and misconceptions

• Misconception: Distribution and density mean the same thing. Correct: Distribution describes how people are spaced over the earth's surface. Density relates the number of people to land area and is usually measured in persons per sq km.
• Misconception: Population growth necessarily means an increase. Correct: Population change may be positive or negative. It measures a change in the number of inhabitants during a specified period, expressed as an absolute number or a percentage.
• Misconception: Natural growth includes migration. Correct: Natural growth is births minus deaths. Actual growth also includes in-migration and out-migration, so the two concepts use different components of population change.
• Misconception: Population can grow only when the birth rate rises. Correct: A decreasing death rate also contributes to population growth. The balance between births and deaths matters, as the second stage of demographic transition demonstrates.
• Misconception: An immigrant and an emigrant must be different people. Correct: The same migrant is an emigrant from the place of origin and an immigrant into the place of destination.
• Misconception: Better job opportunities are a push factor. Correct: They are a pull factor making a destination more attractive. Unemployment is a push factor making the origin seem less attractive.
• Misconception: High fertility makes population growth rapid in the first demographic stage. Correct: Mortality is also high, and growth is slow. In the second stage, reduced mortality alongside initially high fertility produces a high net addition.
• Misconception: Population necessarily stops growing in the last demographic stage. Correct: Population is either stable or grows slowly. Both fertility and mortality decline considerably, and people deliberately control family size.

Exam-style questions with model answers

Q1. Define population density and state its usual unit. [2 marks]

1. Population density is the ratio between the number of people and the size of the land they occupy.
2. It is calculated by dividing population by area and is usually measured in persons per sq km.

Q2. What are the three components of population change? [2 marks]

1. The three components are births, deaths and migration.
2. Births and deaths determine natural growth. Actual growth also accounts for people moving into and out of the region.

Q3. Distinguish between crude birth rate and crude death rate. [3 marks]

1. Crude birth rate is the number of live births in a year per thousand of population. Its formula is CBR = (B / P) × 1000, where B means live births.
2. Crude death rate is the number of deaths in a particular year per thousand of population. Its formula is CDR = (D / P) × 1000, where D means deaths.
3. In both calculations, P is the estimated mid-year population. The distinction is the event being counted: live births or deaths.

Q4. Distinguish between push and pull factors of migration. [3 marks]

1. Push factors make the origin seem less attractive. They include unemployment, poor living conditions, political turmoil, unpleasant climate, natural disasters, epidemics and socio-economic backwardness.
2. Pull factors make the destination seem more attractive than the origin. They include better job opportunities and living conditions, peace and stability, security of life and property, and pleasant climate.
3. The distinction is between conditions encouraging departure from the origin and conditions attracting people to the destination.

Q5. Explain the geographical factors influencing population distribution. [5 marks]

1. Availability of water is important because people need fresh water for drinking, bathing, cooking, cattle, crops, industries and navigation. River valleys are among the world's most densely populated areas.
2. People prefer flat plains and gentle slopes because they favour crop production, roads and industries. Mountains hinder transport networks and initially do not favour agricultural and industrial development. They tend to be less populated.
3. A comfortable climate with little seasonal variation attracts people. Very heavy rainfall and extreme and harsh climates are associated with low population.
4. Fertile loamy soils support intensive agriculture and attract more people.
5. The Ganga plains and sparsely populated Himalayan mountain zones illustrate the influence of landforms.

Q6. Explain how economic factors influence population distribution, using examples. [5 marks]

1. Mineral deposits attract industries. Mining and industrial activities generate employment, drawing skilled and semi-skilled workers and making these areas densely populated.
2. The Katanga Zambia copper belt in Africa is an example of population concentration associated with mining and industry.
3. Urbanisation attracts people through better employment opportunities, educational and medical facilities, transport and communication, civic amenities and city life. This leads to rural to urban migration and growth in city size.
4. Industrial belts provide jobs for factory workers and for transport operators, shopkeepers, bank employees, doctors, teachers and other service providers.
5. The Kobe-Osaka region of Japan is thickly populated because of its industries. This illustrates the connection between industrial employment and the concentration of population.

Q7. Describe the three stages of demographic transition. [5 marks]

1. The first stage has high fertility and mortality. People reproduce more to compensate for deaths due to epidemics and variable food supply, so population growth is slow.
2. In the first stage, most people work in agriculture, where large families are an asset. Life expectancy and technology are low, and people are mostly illiterate.
3. In the second stage, fertility is initially high but declines with time. Better sanitation and health conditions reduce mortality. The resulting gap produces a high net addition to population.
4. In the last stage, fertility and mortality decline considerably. Population is stable or grows slowly. People are urbanised and literate, possess high technical know-how and deliberately control family size.
5. The transition describes movement from rural, agrarian and illiterate society towards urban, industrial and literate society.

Q8. Explain family planning and identify population control measures. [3 marks]

1. Family planning is the spacing or preventing of the birth of children. Access to its services is significant for limiting population growth and improving women's health.
2. Propaganda, free availability of contraceptives and tax disincentives for large families are some measures that can help population control.
3. Preventive checks are better than physical checks. Controlling rapid population increase is necessary for the sustainability of resources.

Key takeaways

• Population distribution describes the spacing of people, while density relates their number to land area.
• Water, landforms, climate and soils influence settlement by shaping living conditions, agriculture, transport and industry.
• Minerals, urbanisation and industrialisation attract people through employment, services and the opportunities available in cities.
• Population change involves births, deaths and migration; natural growth and actual growth include different components.
• Crude birth and death rates count annual events per thousand of population using estimated mid-year population.
• Migrants leave an origin and enter a destination; push and pull factors explain the pressures and attractions involved.
• Demographic transition moves from high births and deaths towards low births and deaths as society changes.
• Family planning includes spacing or preventing births and helps limit population growth while improving women's health.

Test yourself

What does population distribution describe?

It describes the way people are spaced over the earth's surface.

Why are river valleys among the most densely populated areas?

People prefer easily available fresh water for domestic needs, cattle, crops, industries and navigation.

Why do mountainous and hilly areas tend to be less populated?

They hinder transport networks and hence initially do not favour agricultural and industrial development.

How does actual growth differ from natural growth?

Natural growth is births minus deaths. Actual growth also adds in-migration and subtracts out-migration.

What does P represent in the CBR and CDR formulae?

It represents the estimated mid-year population used as the denominator in calculating the rate.

How can the same person be an immigrant and an emigrant?

The person is an emigrant from the origin and an immigrant into the destination.

Why is net population addition high in the second demographic stage?

Fertility is initially high while improved sanitation and health conditions reduce mortality, creating a gap between the rates.

What did Malthus's theory of 1798 predict?

Population would increase faster than food supply, with further increase resulting in a crash caused by famine, disease and war.