GeographyICSE Class 8 · Population Dynamics

Distribution of World Population, Over-population and Under-population (ICSE Class 8)

Updated 17 October 2026 · Draft, not yet fact-checked

World population is spread unevenly: dense in fertile plains, river valleys and industrial regions, and thin in deserts, polar lands, dense forests and high mountains. Density = total population / area in sq km. Over-population means more people than the resources can support at a decent standard of living; under-population means too few people to use the resources fully. Both depend on resources and technology, not on numbers alone.

Compare the orange people bar with the green resources bar: too few people leave resources unused, too many leave resources short.

Illustration drawn for QuestionBuddy.

Understand World Population Distribution, Over-population and Under-population

1. Distribution and density. Distribution shows how people are spread over the Earth. *Population density* = total population / total land area, in persons per sq km. It is an average, so it hides differences inside a country.

2. Densely populated regions. East Asia (eastern China, Japan, Korea), South Asia (the Ganga plains, Bangladesh), Europe and the north-eastern USA. They have fertile plains, a good climate, water, industry and transport.

3. Sparsely populated regions. Hot deserts (Sahara, Arabia), cold regions (northern Canada, Siberia, Greenland, Antarctica), dense equatorial forests (interior Amazon, Congo basin) and high mountains (Himalaya, Andes).

4. Factors affecting distribution.

*Geographical:* relief (plains attract, mountains repel), climate (moderate attracts), soil (fertile soil supports farming), water (rivers and lakes), minerals (mining towns).
*Economic:* industries, jobs, trade and transport draw people to cities.
*Social and cultural:* religious or cultural centres, safety and government policies.

5. Over-population. A region has more people than its land, water, food, jobs and services can support at a reasonable standard of living. Examples often discussed: Bangladesh (very high density) and some crowded cities of developing countries. Impact on society: unemployment and poverty, shortage of food, water and housing, overcrowded schools, hospitals and transport, slums, pollution and pressure on forests, and social tension.

6. Under-population. A region has fewer people than are needed to use its resources fully. Examples often discussed: Australia and Canada, with large areas and rich resources but small populations. Impact: shortage of workers so that resources stay undeveloped, costly services for scattered people, small markets for industry, dependence on immigrants and, in ageing countries, too few workers to support the old.

7. Optimum population. The size at which people use resources best and enjoy the highest standard of living with the available technology.

8. A key idea. Over- or under-population depends on resources and technology. A small country with advanced industry and trade, though densely populated, may not be over-populated, while a country with few people but poor technology can be unable to use its resources.

World Population Distribution, Over-population and Under-population: key facts

Density: $D e n s i t y = t o t a l p o p u l a t i o n / t o t a l a r e ain s q k m ∣ U ni t : p er so n s p er s q k m$
Dense regions: East Asia
South Asia
Europe
North-eastern USA
Sparse regions: Hot deserts
Polar lands
Equatorial forests
High mountains
Examples: Over-population: Bangladesh | Under-population: Australia and Canada

How to answer World Population Distribution, Over-population and Under-population questions

For a density question, write the formula, substitute, and give the unit.

1For distribution questions, name the region and give a geographical, economic or social reason.
2For over- or under-population, say how people compare with resources and technology.
3Add one impact on society and one example.
4Avoid saying over-population just means a large number.

World Population Distribution, Over-population and Under-population in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Two islands

Suppose Island A has 3,000,000 people on 6,000 sq km of fertile land with many factories and ports. Island B has 90,000 people on 30,000 sq km of land rich in minerals but with no roads or power.

Find the density of each island and say which could be called under-populated and why.

Try it first, then show the solutionSolution

Density A = 3,000,000 / 6,000 = 500 persons per sq km.
Density B = 90,000 / 30,000 = 3 persons per sq km.
Island B has too few people and little infrastructure to use its minerals, so it is under-populated; A is dense but its resources and industry may support its people.

Answer: A: 500 per sq km; B: 3 per sq km; B is under-populated.

Memory hook: Compare people with what the land can use.

Tricks to remember World Population Distribution, Over-population and Under-population

Short memory aids. Say each one aloud once, then use it on a question the same day.

People over area
Density is people per sq km, so divide the number of people by the area.
Use it when: Density sums.
Fertile plains fill, fringes empty
Think of fertile, flat, wet places as full and hot, cold, dense or very high places as empty.
Use it when: Distribution questions.
Over = too many for resources
The test is the resources and technology, not just the total.
Use it when: Defining over-population.

World Population Distribution, Over-population and Under-population: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Density · 2 marks · Short answerBoard level

A country has 54,000,000 people and an area of 360,000 sq km. Find its population density.

Try it first, then show the solutionSolution

Density = population / area.
= 54,000,000 / 360,000.
= 150 persons per sq km.

Answer: 150 persons per sq km.

Example 2: Sparse regions · 2 marks · Short answerBoard level

Name two sparsely populated regions of the world and give one reason for each.

Try it first, then show the solutionSolution

Sahara (hot desert): very little water and extreme heat make farming and living hard.
Antarctica or Greenland (cold regions): ice and extreme cold make it unsuitable for settlement.

Answer: Sahara: aridity; Antarctica: extreme cold.

Example 3: Compare two countries · 4 marks · Long answerHarder board level

Country P has 36 million people on 480,000 sq km. Country Q has 120 million people on 150,000 sq km. (a) Find each density. (b) Can we call Q over-populated from this alone? Explain.

Try it first, then show the solutionSolution

(a) P: 36,000,000 / 480,000 = 75 persons per sq km. Q: 120,000,000 / 150,000 = 800 persons per sq km.
(b) Not from density alone. Over-population depends on whether resources, jobs and technology support the people at a reasonable standard of living.
If Q has advanced industry, trade and imports of food, it may support its people well.

Answer: (a) P 75; Q 800 per sq km (b) Not necessarily; depends on resources and technology.

Example 4: Impact of over-population · 3 marks · Short answerHarder board level

List three effects of over-population on society and suggest one remedy.

Try it first, then show the solutionSolution

Effects: unemployment and poverty; shortage of food, water and housing leading to slums; overcrowded schools, hospitals and transport; pollution.
Remedy: family planning and education, or creating jobs and services in other regions.

Answer: Unemployment, slums, pressure on services; remedy: family-planning and education or job creation.

Example 5: Explain the pattern · 4 marks · Long answerHOTS / competency

Explain why the Ganga plains are densely populated while the Amazon interior is sparsely populated. Use three different factors.

Try it first, then show the solutionSolution

Ganga plains: flat fertile alluvial soil, plentiful water and a moderate climate support farming and large populations.
Amazon interior: dense equatorial forest makes farming, roads and building difficult.
Heat, humidity and disease, and distance from markets and few jobs discourage settlement.

Answer: Relief, soil and water favour the Ganga plains; dense forest and poor access limit the Amazon interior.

Where students lose marks in World Population Distribution, Over-population and Under-population

The slips examiners see most often, and what to write instead.

Mistake: Missing the unit in density
The answer is a bare number.
Wrong working
Density = 150
Right working
Density = 54,000,000 / 360,000 = 150 persons per sq km
Do this: Always write persons per sq km.
Usually costs: 1 mark.
Mistake: Equating over-population with a large number
Total population is used without resources.
Do this: Define over-population by comparing people with resources and technology.
Usually costs: 1 to 2 marks.
Mistake: Naming only a region without a reason
Distribution answers list places.
Do this: Give a factor: relief, climate, water, soil or jobs.
Usually costs: 1 mark.
Mistake: Arithmetic slips in zeros
Large numbers are divided carelessly.
Do this: Cancel zeros step by step and check by multiplying back.
Usually costs: 1 mark.

Exam tips

Write density as a formula, substitution and unit.
Always give at least two factors in distribution answers (geographical plus economic).
In over- or under-population answers, mention resources and technology.
Quote examples carefully: Bangladesh (over), Australia and Canada (under).

Practice questions on World Population Distribution, Over-population and Under-population

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which of the following is usually densely populated?
(a) Sahara
(b) Greenland
(c) Ganga plains
(d) Andes peaks
Hint
Flat, fertile and wet.
Answer
(c) Ganga plains.
Q2 · 1 mark · Very short answerBoard level
Define population density and give its unit.
Hint
Formula in words.
Answer
Population density is the average number of people per unit area: total population / area; its unit is persons per sq km.
Q3 · 2 marks · Short answerBoard level
Give one example each of an over-populated and an under-populated country often discussed in geography.
Hint
Think of area and resources.
Answer
Over-populated: Bangladesh. Under-populated: Australia (or Canada).
Q4 · 3 marks · Short answerHarder board level
A city district has a population of 2,40,000 on 8 sq km. A rural district has 9,000 people on 150 sq km. Find both densities and the ratio of the first to the second.
Hint
Divide, then compare.
Answer
City: 240,000 / 8 = 30,000 per sq km. Rural: 9,000 / 150 = 60 per sq km. Ratio = 30,000 / 60 = 500, so the city is 500 times as dense.
Q5 · 1 mark · Assertion-reasonHarder board level
Assertion (A): A country with a high density is not always over-populated.
Reason (R): Over-population is judged by the balance between people, resources and technology.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Does R explain A?
Answer
(a).
Q6 · 3 marks · Short answerHarder board level
Explain three problems caused by under-population in a resource-rich country.
Hint
Think of workers, services and markets.
Answer
Resources stay undeveloped for want of workers; services such as roads and schools cost more because people are scattered; the home market is too small for industries, so the country may depend on immigrants.
Q7 · 4 marks · Case-basedHOTS / competency
A district has 20 sq km of cultivable land and 5,000 people. Each hectare of land can feed 4 people at a decent standard (1 sq km = 100 hectares). (a) How many people can the land feed? (b) Is the district over-populated by this measure? (c) Name two non-farm measures that could help it support more people.
Hint
Convert sq km to hectares.
Answer
(a) 20 x 100 = 2,000 hectares; 2,000 x 4 = 8,000 people. (b) No; 5,000 is below 8,000, so the land can feed them. (c) Industries and services that provide jobs and income, and trade to buy food.
Q8 · 2 marks · Short answerHOTS / competency
Besides fertile land, why do many people live in the industrial regions of Europe and the north-eastern USA? Give two reasons.
Hint
Think beyond farming.
Answer
Industries, trade and services offer jobs and incomes, and good transport and cities attract people. Minerals and ports also encourage settlement.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Formula for density?Show answer
Total population / total area in sq km.
2.Define optimum population.Show answer
The size at which resources are used best and living standards are highest.
3.Name two sparsely populated regions.Show answer
Sahara and Antarctica (also Siberia, the Amazon interior).
4.Name an over-populated example.Show answer
Bangladesh.
5.Name an under-populated example.Show answer
Australia or Canada.

World Population Distribution, Over-population and Under-population: frequently asked questions

Is high density the same as over-population?

No. Over-population depends on whether resources and technology can support the people.

Why is population unevenly distributed?

Because relief, climate, soil, water and economic opportunities vary from place to place.

What is optimum population?

The best size for using resources and giving the highest standard of living with the available technology.

Can a country be under-populated and still poor?

Yes, if it lacks technology and capital to use its resources.