Patterns of population distribution and density

Detail

People as wealth, and what "distribution" means

• A country's people are its real wealth. People use the resources, and people make the policies of a country.
• Population distribution means the way people are spread over the earth's surface. It tells us where people live.
• The spread is very uneven:
• About 90 per cent of the world's people live on about 10 per cent of its land (NCERT).

• So most of the land holds very few people.

• Concentration in a few countries:

• The 10 most populous countries hold about 60 per cent of the world's people (NCERT Fig. 2.1).
• Six of these 10 are in Asia (NCERT).

Cressey's statement

• George B. Cressey wrote about Asia: "Asia has many places where people are few and few places where people are very many."
• What it means:
• Big parts of Asia are almost empty: the Gobi and Thar deserts, the Tibetan plateau, Siberia and the Himalaya.

• A few small parts are very crowded: the Ganga plains, eastern China and Java.

• The same pattern holds for the whole world.

Density of population

• Population density is the number of people living on one unit of land.
• Formula: Density = Population ÷ Area. It is shown as persons per sq km.
• Worked example (NCERT): 1,50,000 people living on 100 sq km → 1,50,000 ÷ 100 = 1,500 persons per sq km.
• Why it matters: density shows how much pressure each unit of land bears. High density means more demand for food, water, housing and jobs from the same piece of land.
• India's density was 382 persons per sq km (Census 2011).

World pattern: dense areas

Region	Main dense clusters	Location anchor	Why crowded (in short)
East Asia	Eastern China, Japan, Korea	Pacific coast, about 20°N–45°N	Fertile plains of the Huang He and Chang Jiang; long settled; industry
South Asia	Ganga-Brahmaputra plains, Indus plains, Kerala coast	India, Bangladesh, Pakistan	Deep alluvial soil (fine, fertile soil laid by rivers); monsoon rain; rice farming
Southeast Asia	Java; Mekong and Irrawaddy deltas	Java: Indonesia, about 7°S. Mekong delta: south Vietnam, on the South China Sea. Irrawaddy delta: Myanmar, on the Andaman Sea	Volcanic soil (Java); deltas (flat, fertile land where a river meets the sea) good for wet rice
Europe	North-western and western Europe	Britain, Germany, Benelux, northern Italy	Industry, cities, mild climate, good transport
North America	North-eastern USA	Boston to Washington, plus the Great Lakes	Industry, ports, big cities
Africa	Nile valley and delta	Egypt, north-east Africa	A ribbon of water and farmland running through the Sahara desert

• Trap: Southeast Asia is NOT a sparse area (NCERT exercise 1(ii)). Java and the river deltas are among the most crowded places on earth.

World pattern: sparse areas

Type	Examples	Why few people
Polar lands	Greenland, northern Canada, Siberia, Antarctica	Very cold; frozen ground; very short growing season
Hot deserts	Sahara (North Africa), Atacama (Chile, about 20°S–27°S, one of the driest places on earth), central Australia	Little water; very hot
Cold desert	Gobi (Mongolia–China)	Dry, with very cold winters
Equatorial forests	Amazon basin (Brazil), Congo basin (central Africa, on the Equator)	Thick forest, heavy rain, poor soil once cleared, disease
High mountains	Himalaya, Andes, Rockies	Steep slopes, cold, thin air, little flat land

Most populous countries today

• India passed China as the world's most populous country in April 2023 (UN estimate). India reached 1,425,775,850 people at the end of April 2023 [2].
• China's population peaked at 1.426 billion in 2022 and has started to fall. India's population is expected to keep growing for several decades [2].
• Fertility rate (the average number of children born to a woman) in 2022: China 1.2; India 2.0. India is just below the replacement level of 2.1 (the number of children needed for each generation to replace the one before) [2].
• Approximate order of the ten most populous countries (mid-2020s, UN estimates): India, China, USA, Indonesia, Pakistan, Nigeria, Brazil, Bangladesh, Russia, then Ethiopia and Mexico close together.

• Six of these ten are in Asia: India, China, Indonesia, Pakistan, Bangladesh and Russia (Russia is counted as Asian here because most of its land lies in Asia).

• World total: about 8.2 billion in 2024. It is projected to peak at about 10.3 billion in the mid-2080s and then fall slowly to about 10.2 billion by 2100 [3].

• In 2024, one in four people lived in a country whose population has already peaked. Examples are China, Germany, Japan and Russia [3].

• India, Indonesia, Nigeria, Pakistan and the USA will keep growing until 2054 or later [3].

• Extreme densities:

• Bangladesh has the highest density among large countries, more than 1,100 persons per sq km.
• City-states have far higher figures. Monaco has about 19,000 persons per sq km and Singapore about 8,000. Almost all of their land is city.

Arithmetic density and physiological density

• Arithmetic density = total population ÷ total land area. This is the normal "density" figure.
• Physiological density = total population ÷ cultivable (farmable) land. It shows how much pressure falls on the land that can actually grow food.
• Why we need it: a country with large deserts looks thinly peopled on arithmetic density. But its farmland may be very crowded.
• Egypt is the best example:
• Only about 4 per cent of Egypt's land is suitable for farming (NASA, 2021) [4].
• About 95 per cent of Egyptians live in towns and cities on the Nile floodplain [4].
• Egypt grew from 45 million in the 1980s to more than 100 million (2021) [4].

• Result: Egypt's arithmetic density is moderate, but its physiological density is very high.

• New pressure on the same farmland:

• Egypt loses about 2 per cent of its arable (farmable) land per decade to the spread of cities [4].
• Near Alexandria, farmland fell 11 per cent between 1987 and 2019 [4].
• Seawater moving into the Nile delta has damaged about 15 per cent of its most fertile farmland [4].

Measure	Divides population by	Shows	Egypt
Arithmetic density	Total land area	General crowding	Looks moderate
Physiological density	Cultivable land	Pressure on food-growing land	Very high

Prelims Hooks

• About 90 per cent of the world's people live on about 10 per cent of its land (NCERT).
• The 10 most populous countries hold about 60 per cent of world population. Six of them are in Asia (NCERT).
• "Asia has many places where people are few and few places where people are very many" was said by George B. Cressey.
• Density = Population ÷ Area. 1,50,000 people on 100 sq km = 1,500 per sq km.
• Trap: Southeast Asia (Java, the Mekong and Irrawaddy deltas) is a dense area, not a sparse one.
• Matches: Atacama → Chile; Gobi → Mongolia–China; Irrawaddy delta → Myanmar; Mekong delta → Vietnam; Java → Indonesia.
• India passed China in April 2023 (UN). China peaked at 1.426 billion in 2022 [2].
• Physiological density = people per unit of cultivable land. Egypt: about 95 per cent of people live on the Nile floodplain, and about 4 per cent of the land can be farmed [4].
• World population was about 8.2 billion in 2024, with a projected peak of about 10.3 billion in the mid-2080s [3].

Mains Points

• The world's population is spread very unevenly.
• Dense areas are fertile river plains and deltas, monsoon rice lands and industrial belts.
• Sparse areas are deserts, polar lands, equatorial forests and high mountains.

• Physical factors explain the empty areas. Economic and historical factors explain the crowded ones.

• Arithmetic density can mislead planners. Physiological density shows the real pressure on farmland.

• Egypt has about 95 per cent of its people on about 4 per cent of its land, and it keeps losing farmland to cities and seawater [4].

• Lesson for India: protect fertile alluvial land in the Ganga plains and on the coasts as cities grow.

• India has become the most populous country (2023) and is still growing, while China is shrinking [2].

• Opportunity: a large working-age population. This is called the demographic dividend.
• Pressure: high density on the Indo-Gangetic plains and in Kerala strains land, water and cities.

• Policy needs: jobs, skills, urban planning and land-use planning (GS-I and GS-III).

• Cressey's idea applies at every scale: world, continent and country.

• In India, the empty Thar, Ladakh and Arunachal Pradesh contrast with the crowded Ganga plains and Kerala.
• So regional plans must be made for each region, not one national average.