GCSE Geography | Megacities (Urbanisation 2)

As people move from rural to urban areas in LICs, attracted by the opportunities for a better quality of life in cities, many people are leaving cities in HICs to live in the countryside. Push–pull factors affect decisions in both situations. One consequence of rural–urban migration in LICs is an increase in the number of megacities.

A megacity is a city with 10 million or more inhabitants.

The current top ten largest megacities are:

1) Toyko, Japan - 37.4 million (pictured below)

2) Delhi, India - 29.3 million (pictured below)

3) Shanghai, China - 26.3 million (pictured below)

4) São Paulo, Brazil - 21.8 million

5) Mexico City, Mexico - 21.6 million

6) Cairo, Egypt - 20.4 million

7) Dhaka, Bangladesh - 20.2 million

8) Mumbai, India - 20.1 million

9) Beijing, China - 19.4 million

10) Osaka, Japan - 19.2 million

Pattern of megacity growth

In the 1970s there were only eight megacities across the world: Tokyo, Osaka, Seoul, Moscow, New York, Los Angeles, Mexico City, and São Paulo - the majority of them were in HICs. In 1980 this had risen slightly to 9 megacities, which then was followed by an increase to 17 in 1990, then 21 in 2000 and 27 in 2010.

Today it is estimated that there are between 33 and 44 megacities - this discrepancy is due to how different organisations measure urban populations, for example the United Nations Department for Social and Economic Affairs (UN DESA) estimate that there are, whereas the Organisation for Economic Co-operation and Development (OECD) report 39 megacities.

Now megacities are mainly found in NEEs where urban population growth has been rapid. Around 80% of megacities are in Asia, particularly SE Asia, such as China, India, Bangladesh and Pakistan - the countries where the majority of our goods are manufactured so economic growth has seen people flock to cities for employment opportunities. More recently we are starting to see them emerge in parts of Africa, such as Lagos in Nigeria and Cairo in Egypt. The map below from Statista shows how much the 15 largest megacities in the world were predicted to grow between 2011 and 2025.

Future megacities

The Institute for Economics and Peace estimates that 70% of the global population will live in cities by 2050 (compared to 57% today), and that there will be another 14 megacities - with Delhi in the top spot, with a projected population of 49.6 million. The map below from Statista shows which cities are expected to hit 10 million people by 2050.

There is also an excellent story map from ArcGIS which explores the growth of the 10 largest megacities - https://storymaps.arcgis.com/s...

Megacities in Africa

Africa currently has three megacities: Cairo (Egypt), Kinshasa (Democratic Republic of Congo) and Lagos (Nigeria), however this is expected to increase to 7 by 2050, with Dar es Salaam (Tanzania), Nairobi (Kenya), Khartoum (Sudan) and Luanda (Angola). Cairo is expected to have the biggest population with 32.6 people, followed by Kinshasa with 29 million and Lagos with 28.2 million. However, Dar es Salaam is expected to see the greatest population growth from 7.5 million today to 16.4 million by 2050 (+118%), and Nairobi's population is set to double from 5.2 million to 10.4 million.

Megacities are economic powerhouses that bring with them a huge range of services and job opportunities, as well as having huge labour markets and millions of potential customers. These factors encourage investment, both from local companies as well as foreign transnational corporations (TNCs), leading to a positive multiplier effect. However, rapid urbanisation can also mean that the infrastructure and services of megacities can struggle to cope with their huge populations, making life challenging for residents. It can also lead to the emergence of informal settlements (see separate notes). LIC/NEE cities can also have high levels of air and water pollution, along with traffic congestion.