Population | ICSE Class 8 Geography Notes

This note covers population distribution and density, factors affecting where people live, births and deaths, population growth, migration, overpopulation and underpopulation, population composition, rural and urban populations, and the interpretation of population pyramids.

What is population, and why are people a resource?

Population means the people living in a particular area at a particular time. Studying population involves more than counting people. It also involves understanding where they live, how their numbers change and what characteristics they have.

Human resources are people considered in terms of their abilities and contribution to society. People recognise uses for materials in nature and develop them to meet their requirements. Healthy, educated and motivated people help turn natural materials into useful resources.

What should a population study explain?

A population study asks how many people live in an area, how they are spread across it and how their numbers change. It also examines age, sex, education, health, occupations and income. An occupation is the work a person does.

These characteristics help explain people's needs and their contribution to society. A count alone does not show how many children need education or how many people belong to older age groups. Nor does it show the skills that people possess.

People contribute in different ways, including farming, building bridges, researching medicines, caring for a home and sharing knowledge with younger generations. Human resources therefore cannot be understood simply as the number of people employed in factories or offices.

Note: A large population and a developed population are different ideas. Education, health, skills and opportunities matter when considering the role of people as a resource.

How is the world's population distributed?

Population distribution is the way people are spread across the earth's surface. Distribution is extremely uneven: some areas are crowded, while others have relatively few people. Densely populated describes areas with many people per unit area; sparsely populated describes areas with few.

Where are the main concentrations?

South and south-east Asia, Europe and north-eastern North America are major crowded regions. Very few people live in high latitude areas, tropical deserts, high mountains and areas of equatorial forests. Latitude describes a position's angular distance north or south of the Equator; high latitudes lie towards the poles.

The Equator is the imaginary line dividing the earth into northern and southern halves. Many more people live north of it than south of it. The pattern of settlement therefore differs both between regions and between the two halves of the earth.

Distribution describes a pattern across space. It does not, by itself, explain why that pattern exists. To explain it, connect the location of people with landforms, climate, soil, water, minerals, employment and facilities.

On a world outline map, shade south and south-east Asia, Europe and north-eastern North America as major concentrations. Use a different symbol for tropical deserts, high mountains and polar regions. Add a key explaining each symbol.

A map key explains the colours or symbols used on a map. Keep the two categories distinct. A region marked as sparsely populated has relatively few inhabitants; the description does not mean that every part is uninhabited.

How does population density differ from population size?

Population size is the total number of people in an area. Population density relates that number to the area's size. It is normally expressed as persons per square kilometre. A square kilometre, written km², is the area of a square with sides one kilometre long.

Definition: Population density is the number of people living in a unit area of the earth's surface.

Population density = population ÷ area. Here, population is the number of people, area is measured in square kilometres, the equals sign means “is equal to”, and ÷ means “divided by”. The resulting density is expressed in persons per km².

How is density calculated?

Consider Region X, with a population of 1,50,000 persons and an area of 100 km². Dividing population by area gives 1,500 persons per km². The letter X is simply the name given to this example region.

The same group can appear crowded in a classroom and less crowded in an assembly hall because the hall has a larger area. This illustrates why total numbers must be related to space when discussing crowding.

Density is an average for the area considered. It does not mean that each square kilometre contains exactly the same number of inhabitants. Nor does a density figure alone tell us whether people have adequate resources, employment, education or health facilities.

Which physical factors influence where people live?

Physical factors are features of the natural environment that affect settlement. These include landforms, climate, soil and water. Their influence helps explain why some environments support large concentrations of people while others have much smaller populations.

How do landforms and climate matter?

Topography means the form of the land surface. People prefer flat plains and gentle slopes because these are favourable for farming, road construction and industries. Mountainous and hilly areas hinder transport development and initially do not favour agricultural and industrial development.

The Ganga plains are among the most densely populated areas of the world. Mountain zones in the Himalayas are scarcely populated. This contrast links population distribution with opportunities for cultivation, transport and other economic activities.

Climate means the usual weather conditions of an area over a long period. People usually avoid extremes of heat and cold. The Sahara desert and polar regions provide examples of environments where harsh climatic conditions discourage large concentrations of people.

Why do water and soil attract settlement?

Fertile soil supports the growth of crops. Fertile plains associated with the Ganga and Brahmaputra in India, Hwang-He and Chang Jiang in China, and the Nile in Egypt are densely populated. Their agricultural opportunities help explain these concentrations.

Fresh water is needed for drinking, cooking and bathing, as well as for cattle, crops and industries. People prefer areas where fresh water is easily available. River valleys are therefore among the world's most densely populated areas.

On an outline map of Asia, locate the Ganga and Brahmaputra plains and the Himalayas. Label the plains as densely populated examples and the mountains as a sparsely populated example. Use separate symbols and an explanatory key.

How do economic, social and cultural factors affect settlement?

Economic factors concern work and livelihoods. Social factors include housing, education and health facilities. Cultural factors include the religious or cultural importance of a place. Together, these factors help explain concentrations that cannot be understood through the physical environment alone.

Why do jobs and minerals attract people?

Industrial areas provide employment opportunities and attract large numbers of people. Osaka in Japan and Mumbai in India are densely populated industrial examples. The attraction of an industrial area extends beyond jobs inside factories.

Industries also create opportunities for transport operators, shopkeepers, bank employees, doctors, teachers and other service providers. Thus, industrialisation, the development of industries, can encourage the growth of a population through several kinds of work.

Areas with mineral deposits attract mining and industrial activities. Diamond mines in South Africa and the discovery of oil in the Middle East encouraged people to settle in those areas. Minerals influence settlement through the work associated with extracting and using them.

What role do facilities and cultural importance play?

Better housing, education and health facilities attract people. Pune is an example associated with such social facilities. Towns and cities also offer transport and communication services that can make them attractive places to live and work.

Places of religious or cultural significance attract people too. Varanasi, Jerusalem and Vatican City are examples. Their attraction is different from the employment offered by an industrial centre, although a place can have more than one reason for attracting inhabitants.

When explaining settlement, identify the factor and then show the connection: an industrial area offers work; a fertile plain supports cultivation; and a place with good facilities offers access to services. Naming a place without explaining this connection leaves the geographical relationship incomplete.

How do births and deaths cause population change?

Population change means a change in the number of people during a specified period. Births add people and deaths reduce their number. Migration, meaning movement into or out of an area, is the other main component of population change.

Birth rate is the number of live births in a year per 1,000 people. Death rate is the number of deaths in a year per 1,000 people. Births and deaths are usually measured through these rates, allowing comparison on a common population basis.

What is natural growth?

Natural growth rate is the difference between birth rate and death rate. Both rates must refer to the same period and use the same basis. This comparison concerns births and deaths; movement into and out of an area is considered separately.

Three drawings use balances labelled Birth Rate and Death Rate. Their headings show Population Increase, Population Steady and Population Decrease. The captions compare the two rates to explain each outcome.

See Fig. 5.4 in your NCERT textbook

How can growth accelerate without more births?

1. Better food supplies and medical care improve people's chances of survival.
2. The number of deaths falls as health conditions improve.
3. The number of births can still remain fairly high.
4. The gap between births and deaths widens, producing a greater natural increase.

A fall in deaths can therefore raise population growth even without an increase in births. To explain an actual change in a country's population, however, movement across its borders must also be included.

How has world population growth changed over time?

For an extremely long period of human history, until the 1800s, world population grew steadily but slowly. Large numbers of babies were born, but many died early. Health facilities were inadequate, and sufficient food was not available for everyone.

What do the historical milestones show?

In 1804, world population reached one billion. A billion means one thousand million. In 1959 it reached three billion, and in 1999 it reached six billion. These are historical milestones rather than statements of the world's population today.

The rise to three billion took 155 years after the one-billion milestone. The next doubling, from three billion to six billion, took 40 years. These intervals illustrate the acceleration of growth during this historical period.

The rapid expansion is often called a population explosion. Better food supplies and medicine reduced deaths while births still remained fairly high. The widening difference between births and deaths was the main reason for the rapid increase.

Do all countries follow the same pattern?

Growth rates vary across the world. In the Kenya example, improving health care lowers death rates while birth rates remain high, producing high growth. The United Kingdom example combines low birth and low death rates with slowing population growth.

A world total therefore combines different national patterns. An increase in that total does not mean every country is growing at the same rate. Keep population size, the amount of change and the rate of change distinct when comparing places.

How does migration change population numbers?

Migration is the movement of people from one place to another. It can occur within a country or between countries. The place of origin is the place a person leaves, and the destination is the place the person moves to.

Emigration means leaving a country, and immigration means entering a country. The same movement is emigration when viewed from the country of departure and immigration when viewed from the country of arrival.

How do arrivals and departures affect totals?

The United States of America and Australia have gained population through immigration. Sudan provides an example of population loss through emigration. These examples concern the contribution of movement to population numbers, rather than the contribution of births and deaths.

Actual population change = births − deaths + arrivals − departures. In this expression, all quantities are numbers of people for the same area and period. The symbol − means subtract, and + means add. Arrivals and departures are also called in-migration and out-migration.

Natural growth considers births and deaths. Actual growth includes migration as well. For a particular area, births and arrivals add people, whereas deaths and departures reduce the number. Considering just one of these components cannot explain the complete change.

Why do people move?

The general trend of international migration is from less developed nations towards more developed nations in search of better employment opportunities. Within countries, large numbers of people may move from rural areas, meaning villages or countryside, to urban areas, meaning towns and cities.

Employment, education and health facilities attract such movement. Migration may be permanent, temporary or seasonal. It also takes place between rural areas, between urban areas and from urban to rural areas, so movement towards cities is not its only form.

What do overpopulation and underpopulation mean?

Overpopulation means that population is too large in relation to the resources and opportunities available to support a satisfactory standard of living. Underpopulation means that population is too small to make full use of the available resources with existing skills and technology.

Standard of living refers to the material conditions in which people live. Resources, employment and access to services matter when judging those conditions. A comparison of people with available support is different from a simple count of inhabitants per square kilometre.

What effects can an imbalance have?

Overpopulation can put pressure on food, water, housing, employment, schools and health services. If demand grows faster than the provision of these necessities, meeting people's needs becomes more difficult. These are possible consequences of pressure on resources, not automatic results of a high density.

Underpopulation can mean a shortage of workers and incomplete use of resources. A country may have resources that cannot be fully developed with the labour and skills available. Here, the difficulty concerns insufficient human capacity in relation to opportunities.

Population balance therefore involves people, resources and the ability to use them. Improving health, education and skills can strengthen people's contribution to development. Immigration can also add people to a country's population, as the Australian example shows.

Why is density alone insufficient evidence?

Bangladesh and Japan are both very densely populated, yet Japan is far more economically developed in the comparison. Their shared density characteristic does not mean they have identical economic circumstances. Equally, immigration into Australia does not by itself prove underpopulation.

Note: Do not label a country overpopulated merely because it is crowded, or underpopulated merely because it has few people per unit area. The relationship between population and resources must be considered.

What does population composition tell us?

Population composition means the structure of a population. It includes age, sex, education, health, occupation and income. The rural and urban division also describes where different groups live. These characteristics reveal much more than a single population total.

How do age and sex help describe a population?

Age composition describes the population's division into age groups. Sex composition describes its male and female population. Examining both together shows how males and females are distributed across the different stages of life.

Dependents are people in age groups considered dependent on the working-age population in this classification. Young dependents are aged below 15 years; elderly dependents are aged over 65 years. Those of working age are described as economically active.

A population with many children has different needs from a population with many elderly people. Schools, teachers and toys are relevant to children's needs. Pensions, wheelchairs and health services are relevant when considering support for elderly people.

Why consider residence and other characteristics?

Rural and urban composition distinguishes populations living in villages and countryside from those living in towns and cities. Movement from rural to urban areas changes where people live and is linked with the search for work, education and health facilities.

Literacy concerns the ability to read and write. Education and skills affect the work people can undertake, while health affects their well-being. Occupation identifies the kind of work done, and income describes the earnings available to people.

Studying composition connects population with the development of human resources. Young people need education, skills and opportunities to become productive. A large number of young people is therefore a resource whose abilities need to be developed, rather than a guarantee of economic progress.

How should a population pyramid be read?

A population pyramid, also called an age-sex pyramid, is a diagram showing population divided into age groups and subdivided into males and females. The width of each bar represents that group's share of the total population.

A percentage, also expressed as per cent, is a share out of one hundred. Where a pyramid uses percentages, its bars show proportions rather than raw numbers of people. Read the scale before interpreting a bar's length.

What do the base and top reveal?

The younger age groups appear at the bottom. The numbers of children below 15 years reflect the level of births. Older groups appear towards the top, showing how many people have survived into old age.

A broad base and rapidly narrowing top can represent high birth and death rates. Many children are born, but a large percentage die in infancy, relatively few become adults and very few reach old age. A narrow base is associated with low birth rates.

The diagram places male bars to the left and female bars to the right. Age groups run upwards and the horizontal scale is labelled Per cent. The younger groups are broad, while older groups become progressively narrower.

See Fig. 5.8 in your NCERT textbook

What is a reliable reading sequence?

1. Identify the country and check whether the scale gives percentages or numbers.
2. Read the age groups and identify the male and female sides.
3. Compare the widths of younger, middle and older age groups.
4. Connect the shape with births, survival and the balance between dependents and the working-age population.

In the India example, decreasing deaths, especially among the very young, allow more infants to survive to adulthood. A relatively large young population means a strong and expanding labour force, or body of people available for work.

What do country case studies reveal about population?

Case study: How does Kenya illustrate growth and age structure?

The Kenya growth example links improving health care with falling death rates while birth rates remain high. The difference between the rates produces high population growth. It shows why examining both rates is necessary to explain a change in population.

The illustrative Kenya pyramid presents a high-birth, high-death pattern. It has a broad base and narrows rapidly towards the top. Relatively few people reach the older age groups. This pyramid pattern and the example of declining deaths describe different aspects of population change.

Male bars extend left and female bars extend right from the centre. The lowest age groups are broad, and the bars narrow sharply upwards. The horizontal axis is labelled Per cent.

See Fig. 5.7 in your NCERT textbook

Case study: How does Japan connect age structure with development?

The Japan example associates low birth rates with a narrow pyramid base. Decreased death rates allow numbers of people to reach old age. The diagram therefore has a different shape from the Kenya example, with a less prominent youngest population.

Male and female bars appear on opposite sides. The base is narrower than several middle age groups, and bars extend into older ages. Age labels rise vertically; percentages run horizontally.

See Fig. 5.9 in your NCERT textbook

Japan also demonstrates why density and economic development must be considered separately. Although both Japan and Bangladesh are densely populated, their levels of economic development differ greatly in this comparison. Crowding alone does not explain the quality of human resources.

Population pyramids show age and sex composition at the time represented. Differences in their shapes help explain population growth and people's needs.

Glossary

• Population — The people living within a particular area at a particular time.
• Human resources — People considered in relation to their abilities and contributions to society.
• Population distribution — The way in which people are spread across the earth's surface.
• Population density — The number of people per unit area, normally expressed per square kilometre.
• Birth rate — The number of live births in a year per thousand people.
• Death rate — The number of deaths in a year per thousand people.
• Natural growth rate — The difference between the birth rate and death rate of a population.
• Migration — Movement of people between places, either within a country or between countries.
• Immigration — Entry into a country, adding people through movement across its borders.
• Emigration — Departure from a country, reducing its population through movement elsewhere.
• Overpopulation — A population too large relative to available resources and opportunities for a satisfactory standard of living.
• Underpopulation — A population too small to use available resources fully with existing skills and technology.
• Population composition — The structure of a population, including age, sex, education, health, occupation and income.
• Population pyramid — A diagram showing the age and sex composition of a population.
• Dependents — People in the young and elderly age groups considered dependent on the working-age population.

Common errors and misconceptions

• Misconception: Population size and density mean the same thing. Correct: Size counts people; density relates their number to the area in which they live.
• Misconception: A high population density proves overpopulation. Correct: Overpopulation concerns the relationship between people and resources, rather than density alone.
• Misconception: Population grows only when births increase. Correct: Falling deaths can increase natural growth while births remain fairly high.
• Misconception: Equal birth and death rates guarantee an unchanged national population. Correct: They mean no natural increase; immigration and emigration can still change the total.
• Misconception: Immigration and emigration describe unrelated movements. Correct: A person leaving one country and entering another is an emigrant from the first and an immigrant to the second.
• Misconception: Every population pyramid must be triangular. Correct: Its shape varies with age structure; the Japan example has a narrow base compared with several middle age groups.
• Misconception: Every country grows at the same rate as the world total. Correct: Population growth rates vary; countries can have different combinations of birth and death rates.

Exam-style questions with model answers

Q1. Define population distribution and population density. [2 marks]

1. Population distribution is the way people are spread across the earth's surface.
2. Population density is the number of people per unit area, normally expressed as persons per square kilometre.

Q2. Region X has 1,50,000 people and an area of 100 square kilometres. Calculate its population density, showing the method and unit. [2 marks]

1. Population density is calculated by dividing the population of the region by its area: 1,50,000 divided by 100.
2. The population density of Region X is therefore 1,500 persons per square kilometre.

Q3. Explain three physical factors that influence population distribution: landforms, water and soil. [3 marks]

1. Flat plains and gentle slopes favour cultivation, roads and industries, making them attractive for settlement. Mountainous land hinders the development of transport networks.
2. Easily available fresh water attracts people because it is needed for drinking, cooking, crops, cattle and industries.
3. Fertile soil provides suitable land for agriculture. Agricultural opportunities help explain why fertile plains support large concentrations of people.

Q4. During a period of population growth, food supplies and medicine improve, deaths fall, and births remain fairly high. Explain the growth in four steps. [4 marks]

1. Improved food supplies help meet people's food requirements, addressing one reason why survival had previously been difficult.
2. Better medicine improves survival, contributing to the fall in deaths described in the question.
3. Births remain fairly high, so people continue to be added through births while fewer are removed through deaths.
4. The difference between births and deaths widens, increasing natural growth. The growth does not require births themselves to have risen.

Q5. Explain five features to examine when interpreting an age-sex population pyramid: age groups, male and female sides, scale, base and upper portion. [5 marks]

1. Read the age groups first. They divide the population into stages of life, with younger groups below and older groups above.
2. Identify the male and female sides. Separate bars allow the two groups to be compared within each age category.
3. Check the horizontal scale. If it shows percentages, each bar represents a share of the total population, rather than a raw count.
4. Examine the base. The younger age groups reflect births, and a narrow base is associated with a low birth rate.
5. Examine the upper portion. It shows survival into older age groups and helps identify the elderly population within the overall age structure.

Q6. A person leaves one country to live in another. Explain emigration, immigration, the effect on the origin and the effect on the destination. [4 marks]

1. From the country being left, the movement is emigration. The person is an emigrant in relation to that country.
2. From the country entered, the same movement is immigration. The person is an immigrant in relation to the new country.
3. The departure reduces the origin's population through out-migration, separately from any births or deaths occurring there.
4. The arrival adds to the destination's population through in-migration, separately from its natural population change.

Q7. World population reached 1 billion in 1804, 3 billion in 1959 and 6 billion in 1999. State the two elapsed intervals and the population change during the second interval. [3 marks]

1. The interval from 1804 to 1959 was 155 years. During this period, the population moved from the one-billion milestone to three billion.
2. The interval from 1959 to 1999 was 40 years, much shorter than the earlier interval between the supplied milestones.
3. During the second interval, world population doubled from three billion to six billion. This conclusion uses the two totals given for that interval.

Q8. Bangladesh and Japan are both very densely populated, but Japan is far more economically developed in this comparison. Using these facts, explain why density alone cannot establish overpopulation. [3 marks]

1. Both countries share the characteristic of very high population density, meaning many people live within a unit area.
2. Their economic development differs greatly despite that shared characteristic, so density does not by itself reveal their economic circumstances.
3. Overpopulation concerns population in relation to available resources and opportunities. The supplied density comparison alone is therefore insufficient to classify either country as overpopulated.

Key takeaways

• Population distribution describes where people live, while population density relates their number to the area they occupy.
• Landforms, climate, soil, water, minerals, employment and social or cultural attractions help explain unequal population distribution.
• Births and deaths determine natural growth, while migration must also be considered when explaining actual population change.
• Improved food supplies and medicine can accelerate growth by reducing deaths while births remain fairly high.
• Immigration adds people to a destination country; emigration removes people from their country of origin.
• Overpopulation and underpopulation concern the relationship between people and available resources, rather than population density alone.
• Age-sex pyramids reveal population composition through the relative widths of male and female bars in different age groups.
• Education, health, skills and opportunities help people develop their abilities and contribute as human resources.

Test yourself

Why can a classroom appear crowded while an assembly hall accommodates the same group more comfortably?

The assembly hall has a larger area, so the same number of people occupies a larger space.

What information is needed to calculate population density?

The total population and the area it occupies are needed; divide population by area.

Why do river valleys attract large populations?

They provide access to fresh water needed for people, crops, cattle and industries.

Can natural growth increase while births remain fairly high but unchanged?

Yes. If deaths fall, the gap between births and deaths can widen and increase natural growth.

What is the difference between natural growth and actual population change?

Natural growth considers births and deaths; actual population change also includes arrivals and departures through migration.

What does a broad base in a population pyramid represent?

It represents large younger age groups, whose size reflects the level of births.

Which dependent age groups are used in this population classification?

Young dependents are aged below 15 years, and elderly dependents are aged over 65 years.

Why does a large young population need education and skills?

Education, skills and opportunities help young people develop their abilities and become productive human resources.