🌏 Mostly in Asia
Asia has more megacities than any other continent. Examples are Tokyo in Japan, Delhi and Mumbai in India, Shanghai and Beijing in China, and Dhaka in Bangladesh.
Growing Cities » The Rise of Megacities
What you'll learn this session
Study time: 30 minutes
Edexcel spec: 6.1 A growing percentage of the world's population lives in urban areas (b)
- What a megacity is
- Where the world's megacities are
- How the number of megacities has grown
- Why the number has grown
Urban Environments is an optional topic. Check with your teacher that it is one of the two topics you are studying in Paper 2 Section A.
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Unlock This CourseWhat is a megacity?
Some cities are so big that ordinary words like "large" do not seem enough. Geographers give them their own name.
Key terms:
- Megacity: a city with a population of at least 10 million inhabitants.
That is the definition in the Edexcel specification, so learn it exactly. To picture it, 10 million is more than the whole population of many countries. Every megacity is a huge urban area full of homes, jobs, roads and services.
Megacities are the largest end of the urban story from the last two lessons. Cities grow through rural-urban migration and natural increase. In a few places, this has gone on for so long that the city has passed the 10 million mark.
Where are the megacities?
Megacities are not spread evenly around the world. Look at an atlas or a world map of megacities and a pattern appears.
🌎 Other continents
There are megacities in Latin America, such as Mexico City and São Paulo, and in Africa, such as Cairo. North America has New York.
Tokyo is the largest city in the world, with a population of about 37 million in 2018 (United Nations figures). Most of the other megacities are in the developing and emerging world. A few, such as Tokyo and New York, are in high-income countries.
Learn this
Most megacities are in Asia. The great majority are in developing and emerging countries, not developed ones.
How has the number grown?
Megacities are a fairly new idea. Only a handful of cities have ever reached 10 million people, and almost all of them did so in the last 70 years.
📅 1950
Only two cities were this big: New York and Tokyo.
📈 1990
There were 10 megacities.
🏙 2018
There were 33 megacities. The United Nations expects about 43 by 2030.
The numbers come from the United Nations report World Urbanization Prospects. The exact count changes slightly between reports, but the pattern does not: the number of megacities has risen very fast, and most of the new ones have appeared in Asia, Africa and Latin America.
Skill: describing a trend
When you describe a change over time, quote the figures and the dates. Do not just say "it went up". Write: "The number of megacities rose from 10 in 1990 to 33 in 2018, more than three times as many."
Why has the number grown?
You already know the two ways a city grows. They explain most of the story. Here they are, with the extra reasons that push a city over the 10 million line.
- Rural-urban migration. Millions of people have left the countryside for cities in developing and emerging countries, looking for work and services. Big cities attract the most migrants, so the biggest cities grow fastest.
- Natural increase. Many migrants are young adults who have children in the city. Birth rates are higher than death rates, so the population keeps rising even without new arrivals.
- Economic growth. Many Asian countries have grown rich quickly. Cities with factories, offices, ports and banks create jobs, and jobs attract more people. Growth feeds on itself.
- Growth of the whole population. The world's population has risen strongly, so there are simply more people who could end up living in cities.
- Cities spreading and joining. As a city spreads outwards, it can swallow the towns and villages around it. The built-up area, and its population, becomes bigger.
Worked example
Question: Explain why a city in a developing country may become a megacity.
Answer: The country still has many people in the countryside, so rural-urban migration is high. (1) Most migrants are young, so they have children in the city and natural increase is high. (1) The city has many jobs in industry and services, so more people keep arriving. (1) Together these push the population above 10 million. (1)
Notice that megacities are mainly a developing-world story. Developed countries already urbanised long ago and have slow population growth, so few of their cities are still growing towards 10 million.
Common mistakes
- Defining a megacity as just "a very big city". The number matters: at least 10 million inhabitants.
- Saying all megacities are in developing countries. Tokyo and New York are in high-income countries. Say "most".
- Writing that megacities are in Asia only. Most are in Asia, but there are others in Latin America, Africa and North America.
- Giving only one reason for the growth. Use at least two, such as migration and natural increase.
Exam-style question
(a) State what is meant by a megacity. [1 mark]
(b) Describe the change in the number of megacities between 1990 and 2018. Use these figures: 10 megacities in 1990 and 33 megacities in 2018. [2 marks]
(c) Explain why the number of megacities has increased. [3 marks]
Model answer
(a) A city with a population of at least 10 million people. (1)
(b) The number rose from 10 in 1990 to 33 in 2018. (1) That is an increase of 23, so there are more than three times as many. (1)
(c) Many people have moved from the countryside to the city to find jobs and services, so the city population grows. (1) Many of these migrants are young and have children in the city, so natural increase is high. (1) Economic growth creates jobs and attracts even more people, which pushes more cities over 10 million. (1)
Exam tip
In a "describe the change" question, use the figures and the dates from the question, and do a small calculation such as the increase of 23. That is where the second mark usually comes from.