Chapter 2 – The World Population: Distribution, Density and Growth | CBSE Notes

GEOGRAPHY | CLASS XII | NCERT

Book: Fundamentals of Human Geography | Unit-II | Chapter 2

The World Population: Distribution, Density and Growth

⭐ Topper Level 💬 Easy Language 📌 Point-Wise 🌍 Second Chapter

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1. Learning Objectives

After reading these notes, you will be able to:

Understand the patterns of population distribution and density in the world.

Know the geographical, economic and social-cultural factors influencing population distribution.

Understand population growth, its components (births, deaths, migration) and related concepts.

Know the Demographic Transition Theory and population control measures.

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2. Patterns of Population Distribution in the World

The people of a country are its real wealth — they are the actual resources, make use of a country’s other resources and decide its policies. The world at the beginning of the 21^st century recorded the presence of over 6 billion population. Population distribution refers to the way people are spaced over the earth’s surface.

📌 George B. Cressey on Asia’s Population
“Asia has many places where people are few and few places where people are very many” — this remark about Asia is true of the pattern of population distribution of the whole world as well; the population of the world is unevenly distributed.

90%

of the world’s population lives in about 10% of its land area

60%

of the world’s population is contributed by the 10 most populous countries

6 of 10

of the most populous countries are located in Asia

Fig. 2.1 (Most Populous Countries) ranks China and India at the top, followed by U.S.A., Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia and Mexico.

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3. Density of Population

Each unit of land has a limited capacity to support people living on it. Hence, it is necessary to understand the ratio between the number of people and the size of land — this ratio is the density of population, usually measured in persons per sq km.

📌 Formula

Density of Population = Population ÷ Area

Example: If area of Region X = 100 sq km and population = 1,50,000 persons, then Density = 1,50,000 ÷ 100 = 1,500 persons/sq km.

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4. Factors Influencing the Distribution of Population

🌱 I. Geographical Factors

Availability of water: The most important factor for life — used for drinking, bathing, cooking, cattle, crops, industries and navigation. River valleys are among the most densely populated areas of the world.
Landforms: People prefer flat plains and gentle slopes as these favour crop production, roads and industries. The Ganga plains are among the most densely populated areas, while the Himalayan mountain zones are scarcely populated.
Climate: Extreme heat or cold deserts are uncomfortable for habitation. Areas with comfortable climate and little seasonal variation attract more people — e.g., Mediterranean regions due to their pleasant climate.
Soils: Fertile loamy soils support intensive agriculture and thus more people; areas with poor soils remain thinly populated.

💰 II. Economic Factors

Minerals: Mineral deposits attract industries and generate employment, drawing skilled and semi-skilled workers — e.g., Katanga-Zambia copper belt in Africa.
Urbanisation: Cities offer better employment, education, medical facilities and transport, causing rural to urban migration; mega cities attract large numbers of migrants every year.
Industrialisation: Industrial belts attract not just factory workers but also transport operators, shopkeepers, bank employees, doctors and teachers — e.g., the Kobe-Osaka region of Japan is thickly populated due to industries.

🕌 III. Social and Cultural Factors

📌 Social & Cultural Pull/Push

Some places attract more people due to religious or cultural significance, while people move away from places with social and political unrest. Governments sometimes offer incentives to settle people in sparsely populated areas or to move people away from overcrowded places.

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5. Population Growth

Population growth (or population change) refers to the change in the number of inhabitants of a territory during a specific period of time — it may be positive or negative, expressed in absolute numbers or percentage. It is an important indicator of economic development, social upliftment and the historical-cultural background of a region.

📖 Basic Concepts of Population Geography

📊 Growth of Population

Change of population in a particular area between two points of time (in actual numbers). E.g., India’s population 2011 (121.02 crore) − 2001 (102.70 crore) = growth of 18.15 crores.

📉 Growth Rate

The change of population expressed in percentage.

🌿 Natural Growth

Population increased by the difference between births and deaths: Natural Growth = Births − Deaths.

🔄 Actual Growth

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

Positive Growth

When birth rate > death rate, or people migrate permanently into a region

Negative Growth

When population decreases — birth rate falls below death rate, or people migrate out

👶 Components of Population Change — Births, Deaths & Migration

📌 Crude Birth Rate (CBR)

Number of live births in a year per thousand of population.
CBR = (B ÷ P) × 1000  (B = live births during the year; P = estimated mid-year population)

📌 Crude Death Rate (CDR)

Number of deaths in a particular year per thousand of population.
CDR = (D ÷ P) × 1000  (D = number of deaths; P = estimated mid-year population)

Mortality rates are affected by a region’s demographic structure, social advancement and levels of economic development.

🧳 Migration

The place migrants move from is the Place of Origin (population decreases); the place they move to is the Place of Destination (population increases).
Migration may be permanent, temporary or seasonal, and can occur rural-to-rural, rural-to-urban, urban-to-urban or urban-to-rural.
Immigration: Migrants who move into a new place → Immigrants. Emigration: Migrants who move out of a place → Emigrants. (The same person is both an immigrant and an emigrant.)
Push factors (make origin less attractive): unemployment, poor living conditions, political turmoil, unpleasant climate, natural disasters, epidemics, socio-economic backwardness.
Pull factors (make destination more attractive): better job opportunities, better living conditions, peace and stability, security of life and property, pleasant climate.

📌 Do You Know?

Human population increased more than ten times in the past 500 years. In the twentieth century alone, population increased four times.

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6. Demographic Transition Theory

The Demographic Transition Theory describes and predicts the future population of any area. It states that population changes from high births and high deaths to low births and low deaths as a society progresses from rural agrarian and illiterate to urban industrial and literate. These stages are collectively called the demographic cycle.

1️⃣ Stage I — High Fluctuating

High fertility and high mortality — people reproduce more to compensate for deaths from epidemics and variable food supply. Growth is slow; most people are in agriculture where large families are an asset. Life expectancy is low, literacy and technology levels are low. All countries were in this stage 200 years ago. (Examples today: Bangladesh rainforest tribes.)

2️⃣ Stage II — Expanding

Fertility remains high initially but declines with time; mortality declines due to improved sanitation and health conditions. The gap between births and deaths causes high net addition to population. (Examples: Peru, Sri Lanka, Kenya.)

3️⃣ Stage III — Low Fluctuating

Both fertility and mortality decline considerably; population is stable or grows slowly. Society becomes urbanised, literate, technically advanced, and deliberately controls family size. (Examples: Canada, Japan, USA.)

📌 Key Insight

This shows that human beings are extremely flexible and are able to adjust their fertility. In the present day, different countries are at different stages of demographic transition.

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7. Population Control Measures

Family planning is the spacing or preventing of the birth of children. Access to family planning services is a significant factor in limiting population growth and improving women’s health. Propaganda, free availability of contraceptives and tax disincentives for large families are some measures that help control population.

📌 Thomas Malthus’ Theory (1798)

Malthus stated that the number of people would increase faster than the food supply. Any further increase would result in a population crash caused by famine, disease and war. Preventive checks are better than physical checks. For the sustainability of resources, the world will have to control the rapid population increase.

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Summary — Quick Revision

Distribution: World population is unevenly distributed — 90% lives in 10% of land area; top 10 countries hold 60% of world population, 6 of them in Asia.

Density: Ratio of population to area, measured in persons/sq km. Density = Population ÷ Area.

Factors of Distribution: Geographical (water, landforms, climate, soils), Economic (minerals, urbanisation, industrialisation), Social & Cultural (religious/political significance).

Population Growth: Change in inhabitants over time — Natural Growth = Births − Deaths; Actual Growth = Births − Deaths + In-Migration − Out-Migration.

CBR & CDR: CBR = (Births ÷ Population) × 1000; CDR = (Deaths ÷ Population) × 1000 — both measured per thousand population.

Migration: Origin (decrease) → Destination (increase); Immigrants (in) vs Emigrants (out); Push factors (unemployment, unrest) vs Pull factors (jobs, stability).

Demographic Transition: 3 stages — High Fluctuating (high birth & death) → Expanding (high birth, declining death) → Low Fluctuating (low birth & death, controlled family size).

Population Control: Family planning, contraceptives, tax disincentives; Malthus (1798) — population grows faster than food supply, preventive checks preferred.

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Important Terms to Remember

Population Distribution: The way people are spaced over the earth’s surface.
Density of Population: The ratio between the number of people and the size of land, measured in persons per sq km.
Growth of Population: Change in population of a particular area between two points of time, in actual numbers.
Growth Rate of Population: Change of population expressed in percentage.
Natural Growth: Births minus Deaths in a region between two points of time.
Actual Growth: Births − Deaths + In-Migration − Out-Migration.
Crude Birth Rate (CBR): Number of live births in a year per thousand of population.
Crude Death Rate (CDR): Number of deaths in a year per thousand of population.
Migration: Movement of people from a Place of Origin to a Place of Destination; a spontaneous effort to achieve a better balance between population and resources.
Immigrants / Emigrants: Migrants who move into a new place / migrants who move out of a place.
Push Factors: Conditions that make the place of origin less attractive — unemployment, poor living conditions, political turmoil, natural disasters, epidemics.
Pull Factors: Conditions that make the place of destination more attractive — job opportunities, peace, stability, security, pleasant climate.
Demographic Transition Theory: Theory describing the change in population from high births/deaths to low births/deaths as society progresses from rural agrarian to urban industrial.
Demographic Cycle: The collective stages through which population changes occur — High Fluctuating, Expanding, Low Fluctuating.
Family Planning: The spacing or preventing of the birth of children to limit population growth.
Malthusian Theory (1798): Theory stating population increases faster than food supply, leading to a population crash via famine, disease and war unless checked.