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The World Population: Distribution, Density and Growth

NCERT Class 12 · Geography Based on NCERT Class 12 Geography textbook · Free CBSE study kit

Chapter Notes

**WORLD POPULATION: DISTRIBUTION, DENSITY AND GROWTH**

**SECTION 1: POPULATION DISTRIBUTION PATTERNS**

• **Definition**: Population distribution refers to the way people are spaced over the earth's surface

• **Key Fact**: 90% of world population lives in only 10% of land area

• **Top 10 Most Populous Countries**: Contribute ~60% of world's population; 6 of these are in Asia (China, India, Indonesia, Pakistan, Bangladesh, Japan)

• **Uneven Distribution Pattern**: Asia exemplifies this: "many places where people are few and few places where people are very many" (George B. Cressey)

• **Densely Populated Regions**: River valleys (Nile, Ganges, Yangtze), coastal plains, delta regions

• **Sparsely Populated Regions**: Deserts (Sahara, Kalahari), mountains (Himalayas, Rocky Mountains), rainforests (Amazon)

**SECTION 2: POPULATION DENSITY**

• **Definition**: Ratio between number of people and size of land area

• **Formula**: Population Density = Population ÷ Area (measured in persons per sq km)

• **Example Calculation**: Region X (100 sq km, 1,50,000 population) = 1,500 persons/sq km

• **Interpretation**: Higher density indicates concentration; lower indicates sparse settlement

• **Global Variations**: Netherlands (~400 persons/sq km) vs Australia (~3 persons/sq km)

• **Limitation of CDR**: Does not show distribution pattern; only average measure

**SECTION 3: GEOGRAPHICAL FACTORS INFLUENCING DISTRIBUTION**

**Water Availability**

  • Most critical factor for human survival
  • Used for drinking, agriculture, industries, navigation, cattle rearing
  • River valleys most densely populated globally (Nile, Ganges, Amazon, Yangtze)
  • • Example: Fertile river plains support intensive agriculture and settlement

    **Landforms**

  • Flat plains and gentle slopes: Favourable for agriculture, transport, industry → High population
  • Mountains and hills: Hinder transport networks, agriculture → Low population
  • • Ganges Plains (India): Densely populated due to flat terrain

    • Himalayan zones: Scarcely populated due to mountainous terrain

  • Plateaus: Moderate population depending on altitude and climate
  • **Climate**

  • Extreme climates (hot/cold deserts) uncomfortable for habitation → Low population
  • Temperate, moderate climates with minimal seasonal variation → High population
  • Heavy rainfall areas or extreme/harsh climates → Low population
  • • Mediterranean regions: Historically inhabited due to pleasant climate

    • Tropical rainforests: Low population despite vegetation

    • Polar regions: Minimal population due to extreme cold

    **Soils**

  • Fertile loamy soils support intensive agriculture → High population
  • Poor/laterite soils: Limited agriculture → Low population
  • • Example: Black soil regions (Deccan) vs laterite soils (Western Ghats) in India

    • Chernozem soils (Russia): Support dense agricultural populations

    **SECTION 4: ECONOMIC FACTORS INFLUENCING DISTRIBUTION**

    **Mineral Resources**

  • Mineral deposits → Mining industries → Employment opportunities → Migration → Dense population
  • • Katanga Zambia copper belt (Africa): High population due to mining

    • Chhattisgarh, Jharkhand (India): Population concentration around mineral-rich areas

    **Urbanisation**

  • Cities offer: better employment, educational/medical facilities, transport, communication, civic amenities
  • Attracts rural-to-urban migration → Rapid city growth
  • • Mega cities: Tokyo, Mumbai, Delhi, Shanghai continue attracting millions annually

    • Challenge: Urban overcrowding, pollution, housing shortage, inadequate services

    **Industrialisation**

  • Industrial belts provide jobs for factory workers, transport operators, shopkeepers, service providers
  • Creates multiplier effect → High population density
  • • Kobe-Osaka region (Japan): Dense population due to industries

    • Mumbai-Pune corridor (India): Industrial concentration attracts population

    • Ruhr Valley (Germany): One of world's densest industrial regions

    **SECTION 5: SOCIAL AND CULTURAL FACTORS**

    • **Religious/Cultural Significance**: Sacred places attract pilgrims and permanent settlement

  • Varanasi, Jerusalem, Mecca: High population due to religious importance
  • • **Social/Political Stability**: Unrest causes out-migration → Population decline

    • **Government Incentives**: Nations offer incentives to settle sparsely populated areas

  • Example: Rural development schemes, special economic zones
  • • **Educational Centers**: University towns attract population

    **SECTION 6: POPULATION GROWTH - FUNDAMENTAL CONCEPTS**

    • **Population Growth**: Change in number of inhabitants in a territory during specific period

  • Can be positive or negative; expressed in absolute numbers or percentage
  • Indicator of economic development, social upliftment, historical/cultural background
  • • **Growth Rate of Population**: Population change expressed as percentage

  • Formula: (Current Population - Previous Population) ÷ Previous Population × 100
  • Higher rates indicate rapid growth; negative rates indicate decline
  • • **Natural Growth of Population**: Population increase by difference between births and deaths

  • Formula: Natural Growth = Births − Deaths
  • Does not include migration factor
  • • **Actual Growth of Population**: Includes all components of change

  • Formula: Actual Growth = Births − Deaths + In-migration − Out-migration
  • More accurate for total population change
  • • **Positive Growth**: Occurs when (Births > Deaths) OR In-migration > Out-migration

  • Results in population increase
  • • **Negative Growth**: Occurs when (Deaths > Births) OR Out-migration > In-migration

  • Results in population decrease
  • Examples: Japan, Germany, Russia, Ukraine
  • **Example (India)**: 2001 population = 102.70 crores; 2011 population = 121.02 crores

  • Growth = 18.15 crores in absolute numbers
  • **SECTION 7: COMPONENTS OF POPULATION CHANGE**

    **Crude Birth Rate (CBR)**

    • **Definition**: Number of live births per thousand population in a year

    • **Formula**: CBR = (B ÷ P) × 1000

  • B = Live births during year; P = Estimated mid-year population
  • • **Interpretation**: Higher CBR = younger population/developing countries; Lower CBR = aging population/developed countries

    • **Global Range**: Africa (40+) to Europe (10-15)

    • **India**: ~20 (declining due to education, family planning)

    **Crude Death Rate (CDR)**

    • **Definition**: Number of deaths per thousand population in a year

    • **Formula**: CDR = (D ÷ P) × 1000

  • D = Deaths during year; P = Estimated mid-year population
  • • **Factors Affecting CDR**: Demographic structure, social advancement, economic development, healthcare access

    • **Global Range**: Least developed countries (15-20) to developed countries (8-12)

    • **Impact on Growth**: Declining CDR with constant/high CBR = rapid growth (typical of developing nations)

    **Natural Increase Rate (NIR)**

    • **Formula**: NIR = CBR − CDR

    • **Meaning**: Net population growth from natural factors (births and deaths only)

    • **High NIR**: Developing countries (2-3%); Low NIR: Developed countries (0-0.5%)

    **Migration**

    • **Definition**: Permanent movement of people from one region to another

    • **Components**:

  • In-migration (Immigration): People moving into area
  • Out-migration (Emigration): People moving out of area
  • • **Net Migration**: In-migration − Out-migration

    • **Impact**: Can increase or decrease population independent of natural growth

    • **Examples**:

  • India: Major source of out-migration to USA, UK, Middle East
  • USA: Net positive migration despite lower natural growth
  • Gulf countries: High in-migration for employment
  • **SECTION 8: STAGES OF POPULATION GROWTH (DEMOGRAPHIC TRANSITION MODEL)**

    **Stage I - High Fluctuating Stage**

    • High birth rates (35-50 per 1000)

    • High death rates (30-50 per 1000)

    • Low natural increase

    • Examples: Tribal populations, rainforest communities

    • Reason: High mortality due to disease, malnutrition, poor healthcare

    **Stage II - Early Expanding Stage**

    • Birth rates remain high (40+ per 1000)

    • Death rates fall sharply (15-20 per 1000) due to improved healthcare, sanitation

    • Rapid natural increase (2-3%)

    • Examples: Bangladesh, Peru, Kenya

    • Characteristics: Young population, limited resources

    **Stage III - Late Expanding Stage**

    • Birth rates fall (20-30 per 1000) due to education, family planning

    • Death rates low and stable (5-15 per 1000)

    • Moderate natural increase (1-2%)

    • Examples: Sri Lanka

    • Transition toward stability

    **Stage IV - Low Fluctuating Stage**

    • Low birth rates (10-20 per 1000)

    • Low death rates (10-15 per 1000)

    • Very low natural increase (0-1%)

    • Examples: Canada, USA, Japan

    • Aging population, developed economies

    **CBSE EXAM TIPS:**

    • **Map-Based Questions**: Identify densely/sparsely populated regions; mark major river valleys, mineral-rich areas, urban centers

    • **Diagram Labeling**: Understand Demographic Transition Model stages; label axes (Birth Rate, Death Rate, Time)

    • **Data Interpretation**: Calculate density using formula; interpret CBR/CDR values; compute growth rates

    • **Case Studies**: Compare population patterns of India (dense, young) vs Japan (sparse, aging)

    • **Definitions**: Memorize exact definitions of CBR, CDR, natural growth, actual growth, migration

    • **Numerical Problems**: Practice density calculations and population growth computations

    • **Current Examples**: Use contemporary data on global population distribution for illustration

    MCQs — 10 Questions with Answers

    Q1. Which of the following is the correct definition of population density?

    • A. The total number of people living in a region
    • B. The ratio of population to the area of land measured in persons per sq km ✓
    • C. The growth of population between two time periods
    • D. The birth rate minus the death rate in a region

    Answer: B — Population density specifically measures the number of people per unit area (persons/sq km), not total population, growth, or natural increase.

    Q2. If a region has an area of 500 sq km and a population of 2,50,000 persons, what is its population density?

    • A. 500 persons/sq km ✓
    • B. 250 persons/sq km
    • C. 5,000 persons/sq km
    • D. 5 persons/sq km

    Answer: A — Using the formula Density = Population ÷ Area: 2,50,000 ÷ 500 = 500 persons/sq km.

    Q3. Which geographical factor is the PRIMARY reason why river valleys are among the most densely populated areas of the world?

    • A. Mountainous terrain surrounding the valleys
    • B. Availability of fresh water for multiple human uses ✓
    • C. Proximity to mineral deposits in nearby mountains
    • D. Cold climate that attracts people from warmer regions

    Answer: B — Water is essential for drinking, agriculture, industries, and navigation; river valleys provide this readily, making them naturally attractive for dense settlement.

    Q4. According to the chapter, what percentage of the world's population lives in approximately 10% of its land area?

    • A. 50%
    • B. 70%
    • C. 90% ✓
    • D. 100%

    Answer: C — The chapter explicitly states that 90 per cent of the world population lives in about 10 per cent of its land area, showing extreme uneven distribution.

    Q5. Which of the following pairs correctly matches economic factors with their role in population distribution?

    • A. Mineral deposits → Industrial jobs → Population attraction; Urbanisation → Better facilities → Rural to urban migration ✓
    • B. Climate → Industrial development → Urban growth; Soils → Mining activities → Employment
    • C. Landforms → Commercial opportunities → Migration; Minerals → Agricultural expansion → Settlement
    • D. Water → Manufacturing → Urban centers; Soils → Transportation → City growth

    Answer: A — Minerals attract industries and jobs, while cities attract migrants through better employment, education, and facilities—these are correctly paired cause-effect relationships.

    Q6. What is the correct formula for natural growth of population?

    • A. Natural Growth = Birth Rate + Death Rate
    • B. Natural Growth = Births − Deaths ✓
    • C. Natural Growth = (Births − Deaths) + (In-migration − Out-migration)
    • D. Natural Growth = In-migration − Out-migration

    Answer: B — Natural growth measures only the difference between births and deaths within a region; option C represents actual growth which includes migration.

    Q7. Assertion (A): The Himalayan mountain zones are scarcely populated compared to the Ganga plains. Reason (R): Mountainous areas hinder the development of transport networks and agricultural production. Choose the correct option:

    • A. Both A and R are correct, and R is the correct explanation of A ✓
    • B. Both A and R are correct, but R is NOT the correct explanation of A
    • C. A is correct but R is incorrect
    • D. Both A and R are incorrect

    Answer: A — The Himalayas are indeed sparsely populated because mountains limit transport and farming, unlike the flat Ganga plains—R correctly explains why A is true.

    Q8. The Kobe-Osaka region of Japan is thickly populated primarily because of which factor?

    • A. Its proximity to the Sea of Japan providing fish resources
    • B. The presence of numerous industries in the region ✓
    • C. Its location in a tropical climate zone
    • D. Government policies that incentivize urban settlement

    Answer: B — The chapter specifically mentions that the Kobe-Osaka region is thickly populated due to the presence of industries that create jobs for factory workers, shopkeepers, and service providers.

    Q9. Which statement is INCORRECT regarding population growth components?

    • A. Positive growth occurs when birth rate exceeds death rate
    • B. Negative growth occurs when out-migration exceeds in-migration
    • C. Actual growth excludes the effect of migration from its calculation ✓
    • D. All of births, deaths, and migration are components of population change

    Answer: C — Actual growth INCLUDES migration effects: Actual Growth = (Births − Deaths) + (In-migration − Out-migration); natural growth alone excludes migration.

    Q10. A student studies two regions: Region X with fertile loamy soils in a moderate climate near a river, and Region Y with poor soils in an arid desert. Based on geographical factors of population distribution, which is likely TRUE?

    • A. Region X will have higher population density due to better water, soil, and climate conditions combined ✓
    • B. Region Y will have higher density because deserts create better industrial opportunities
    • C. Both regions will have similar density since economic factors dominate over geography
    • D. Region X will have lower density because rivers attract industries rather than settlement

    Answer: A — Region X combines three favorable geographical factors (water, fertile soil, moderate climate), all of which the chapter identifies as major population attractants, making higher density likely.

    Flashcards

    What percentage of world population lives in what percentage of land?

    90% of world population lives in approximately 10% of Earth's land area.

    Define population density and give the formula.

    Population density is the ratio of people to land area, calculated as: Density = Population ÷ Area (in persons per sq km).

    Name the three components of population change.

    The three components are births, deaths, and migration (in-migration and out-migration).

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

    Natural growth = Births − Deaths; Actual growth = (Births − Deaths) + (In-migration − Out-migration), which includes migration effects.

    Why are river valleys among the most densely populated areas globally?

    River valleys provide fresh water for drinking, agriculture, industries, and navigation, making them naturally attractive for human settlement.

    How does climate influence population distribution?

    Areas with pleasant, moderate climates (like Mediterranean regions) attract more people, while extreme deserts and harsh climates have very low populations.

    What is the crude birth rate (CBR) and how is it calculated?

    CBR is the number of live births per thousand population per year, calculated as: CBR = (B ÷ P) × 1000, where B = births and P = mid-year population.

    Name two reasons why mountainous areas have lower population density than plains.

    Mountains hinder transport network development and agricultural production compared to plains, making them less suitable for large settlements.

    Which continent and how many of the 10 most populous countries are located in Asia?

    Six of the 10 most populous countries in the world are located in Asia.

    What does negative population growth mean and when does it occur?

    Negative population growth occurs when population decreases between two time points, happening when death rate exceeds birth rate or out-migration exceeds in-migration.

    Important Board Questions

    Define population density and calculate the density of a region with an area of 200 sq km and population of 3,60,000 persons. [2 marks]

    Definition: ratio of population to area in persons/sq km. Apply formula Density = Population ÷ Area; divide 3,60,000 by 200 to get 1,800 persons/sq km.

    Explain how water availability and landforms together influence the population distribution pattern in the world. Give one example of each factor from the chapter. [5 marks]

    Water factor: River valleys densest (drinking, agriculture, navigation); Landforms factor: Ganga plains densely settled vs Himalayan mountains sparsely populated. Explain why each factor makes settlement favorable or unfavorable.

    Distinguish between natural growth and actual growth of population. Using the formulas, explain why a region might experience natural growth but negative actual growth. Provide a real-world scenario to illustrate your answer. [5 marks]

    Natural Growth = Births − Deaths; Actual Growth = (Births − Deaths) + (In-migration − Out-migration). Show that positive natural growth can be offset by large out-migration; example: a wealthy country or skilled labor emigration scenario.

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