Megacity In Depth
A megacity of over 10 million people grows faster than its housing and services can keep up. Learn how one develops - its site, its growth, its opportunities and challenges - and how top-down and bottom-up strategies try to make it liveable.
Put it to work, not just to memory
Free and interactive, so you are arguing with the material rather than rereading it.
Start revising freeWhat you'll cover
A city of over ten million
A megacity is an urban area with a population of more than 10 million people. Many of the fastest-growing ones are in developing or emerging countries - Lagos in Nigeria is one example. A megacity grows so fast that its housing, jobs and services struggle to keep up. This module follows one in depth: where it sits, why it grows, the opportunities and challenges that growth brings, and the strategies used to make it more sustainable.
Three words for where and how
To describe a city, geographers use three precise terms. Keep them apart - the exam rewards using the right one.
Site against situation
- Site
- Situation
- Structure
- The physical land the city is built on
- Its position relative to coast, routes and region
- The way land use is arranged from centre to edge
Site or situation?
A megacity is described as being built on "low, flat land around a coastal lagoon". Which term does that description give?
- Site - the physical land the city stands on
- Situation - its position relative to other places
- Structure - how its land use is arranged
- Growth - how fast it is expanding
Why megacities grow so fast
Two forces drive the explosive growth of a megacity:\n\n- Rural-urban migration - people move in from the countryside. Push factors drive them out (rural poverty, few jobs, poor services); pull factors draw them in (jobs, schools, hospitals). - Natural increase - migrants are mostly young adults, so many children are born in the city, and the population keeps climbing. Together these can add enormous numbers every year - far faster than housing and services can be built.
What pulls people in?
Select the TWO PULL factors that attract people from the countryside into a megacity.
- More jobs and higher wages in factories and services
- Better schools, hospitals and services
- Drought and failing harvests in the countryside
- Rural poverty and a lack of farmland
How the city fills up
Put the chain of rapid megacity growth in order, from the countryside to the growing edge of the city.
- Rural push factors (poverty, few jobs) make life hard in the countryside
- City pull factors (jobs, services) attract people towards the megacity
- People migrate from rural areas into the city, mostly young adults
- A young population means high natural increase adds even more people
- Housing cannot keep up, so informal settlements spread on the edges
Two sides of rapid growth
Fast growth is not simply good or bad - it brings real opportunities and serious challenges at the same time, and the exam wants both.
How life varies across the city
- Housing
- Employment
- Services
- Environment
- Planned houses in one area, self-built shacks in another
- Secure office jobs for some, insecure street trading for others
- Piped water and electricity in some districts, little in others
- Clean, green suburbs versus polluted, waste-strewn edges
Spot the bottom-up strategies
Select the TWO strategies that are BOTTOM-UP - small-scale, community-led ways to improve life in a megacity.
- A site-and-service scheme where residents build homes with materials and land provided
- Small loans (microfinance) to help local people start businesses
- A government building a city-wide mass-transit rail network
- The state building a huge new planned district from scratch
Make the city liveable
You advise a megacity on three problems. Choose the most suitable strategy for each.
- An informal settlement has no proper water or sewerage. Residents are keen to improve their own homes but have little money. What suits them best?
- City-wide traffic is gridlocked and air pollution is rising across the whole megacity. What kind of strategy fits a problem this big?
- A minister wants the "best" single approach for the whole city. What is the strongest advice?
Ten million, and growing
A megacity has over _____ million people. It grows through rural-urban _____, driven by push and pull factors, plus natural increase. Rapid growth brings jobs and services but also housing shortages and _____ settlements. Large government schemes are _____ strategies, while small community-led schemes such as site-and-service are _____.
Top-down or bottom-up?
Evaluate whether top-down or bottom-up strategies are better for improving quality of life in a megacity. Use examples of each and come to a supported judgement.
- Describe one top-down strategy (for example a mass-transit system or a large housing project) and what it does well
- Describe one bottom-up strategy (for example site-and-service or microfinance) and what it does well
- Explain a weakness of each - top-down can be costly and may not reach the poorest; bottom-up can be small in scale
- Reach a judgement: explain why a combination often works best, linking each strategy to the problem it fits
The grade-9 checklist
Two things lift a megacity answer into the top band. First, make sure your named city really is a megacity - over 10 million people. A smaller major city will not answer the question. Second, when you describe how life varies across the city, organise it thematically - compare housing, employment, services and environment between the richer and poorer parts of the *same* city. And when you judge strategies, remember the strongest answer usually shows that top-down and bottom-up work best together, each solving the problems it is suited to.