What is urbanisation?
Urbanisation is the increase in the percentage of people living in urban areas (towns and cities) compared with rural areas (villages and countryside). Urban people mostly work in industry and services; rural people more often in farming.
Countries define "urban" differently: some use a minimum population (for example 2,000 or 5,000 people), some add density or type of work. So compare numbers carefully.
Global trend
- 1950: about 30% of the world urban.
- 2007: for the first time, more than half.
- Today: about 55–57%.
- 2050 (UN projection): about 68%.
Rich regions (Europe, North America, Japan) were already 70–80% urban decades ago and now grow slowly. The fastest urbanisation today is in Africa and Asia. India is about 35% urban and rising.
Causes: migration and natural increase
Cities grow in two ways.
- Rural–urban migration: people move from villages to cities.
- Push factors (drive people out of the countryside): few jobs, low and uncertain farm income, drought, floods, lack of land, poor schools and hospitals, conflict.
- Pull factors (draw people to the city): jobs in factories, offices and services, higher wages, better education and health care, entertainment, family already there.
- Natural increase: more births than deaths. Migrants are mostly young adults, so city birth rates rise.
Historically, industrialisation drove urbanisation: the Industrial Revolution pulled workers to factory towns in Britain and Europe in the 1800s. Today farm machines need fewer workers, while services and industry concentrate in cities.
Urbanisation in developed and developing countries
| Higher-income countries | Lower-income / emerging countries | |
|---|---|---|
| Urban share | High (70–90%) | Lower but rising fast |
| Speed | Slow | Fast |
| Main growth | Suburbs; some people leave cities for small towns and countryside (counter-urbanisation) | Migration + natural increase; megacities |
| Main issues | Old housing, inner-city decline, car traffic, rural depopulation | Informal settlements, informal jobs, water, sanitation, traffic |
A megacity has 10 million people or more: examples are Tokyo, Delhi, Shanghai, São Paulo, Mexico City, Cairo, Mumbai, Dhaka and Lagos. Most new megacities are in Asia and Africa.
In many rich countries, while cities stay full, some rural regions lose people (rural depopulation): young people leave and villages age.
Stages
Urbanisation (people move into cities) → suburbanisation (people move to the edges) → counter-urbanisation (people move out to rural areas) → re-urbanisation (people return to renewed city centres).
Urban forms: centre and edge
Most cities have zones:
- Central business district (CBD): offices, shops, tall buildings, high land prices.
- Inner city: older, crowded housing and old industry; may be renewed or decline.
- Suburbs: newer housing, more space, commuters.
- Rural–urban fringe (periphery): where city meets countryside; new estates, malls, airports, and in poorer cities often informal settlements.
When a city spreads outward quickly, this is urban sprawl. Several cities growing into each other form a conurbation or metropolitan region. The periphery is often where both the richest gated estates and the poorest informal homes are built.
Opportunities and challenges of city growth
Opportunities
- More jobs and higher incomes; services (schools, hospitals) are easier to reach.
- Ideas, business and culture spread fast.
Social and economic challenges
- Informal settlements (slums): homes built without permission, often lacking clean water, toilets and electricity.
- Informal jobs: street selling, daily wage work with no contract or safety.
- Inequality, crime, pressure on schools and hospitals.
Environmental challenges
- Traffic and air pollution.
- Waste: huge amounts of rubbish; open dumping pollutes land and water. Solutions: reduce, reuse, recycle, compost, safe landfill, waste-to-energy.
- Urban drainage and flooding: concrete and roads stop rain soaking in, so water rushes into drains and rivers faster, causing flash floods.
- Urban climate: the urban heat island. Buildings and roads absorb heat by day and release it at night; traffic and air-conditioners add heat. Cities can be 2–5 °C warmer than the countryside, especially at night.
Even old industrial cities in rich countries face issues: empty factories and brownfield sites, housing shortage, and inequality between areas.
Sustainable and attractive cities
A sustainable city meets people's needs today without harming future generations. Ideas that work:
- Public transport (metro, buses, cycle lanes, walkable streets) to cut traffic and smoke.
- Green spaces and trees: cooler air, less flooding, better health.
- Water: rainwater harvesting, sewage treatment, fixing leaks.
- Waste: separation at source, recycling, composting.
- Energy: solar roofs, efficient buildings.
- Housing: affordable homes; upgrading slums with residents (self-help schemes) instead of just removing them.
- Brownfield reuse: build on old industrial land instead of green fields.
Case-study ideas: Curitiba (Brazil) for bus rapid transit; Freiburg (Germany) for solar and cycling; Singapore for green buildings and water recycling; Indore (India) for waste separation; Dharavi (Mumbai) for a busy informal economy and debates on upgrading.
Try it: map your own town's changes
Ask an older family member what your town or city looked like 20–30 years ago. List three things that changed (new roads, buildings, lost fields or ponds). Mark each one as an opportunity or a problem. Then in the 3D free-play step, move the urban-share slider from 30% to 70% and say which problem you would fix first.
Key formulas and definitions
- Urbanisation (%) = urban population ÷ total population × 100
- Urban growth = increase in the NUMBER of city people; urbanisation = increase in the SHARE
- City growth = rural–urban migration + natural increase
- Megacity: 10 million or more people
- Stages: urbanisation → suburbanisation → counter-urbanisation → re-urbanisation
- Urban heat island: city often 2–5 °C warmer than surrounding countryside
Worked examples
1. A country has 60 million people; 21 million live in towns and cities. What is its level of urbanisation?
21 ÷ 60 × 100 = 35%.
2. Ten years later the same country has 70 million people, of whom 28 million are urban. Has urbanisation increased? By how much?
28 ÷ 70 × 100 = 40%. It rose from 35% to 40%, an increase of 5 percentage points; the urban number rose by 7 million.
3. A farmer's son leaves his village after two years of drought to work in a factory in the city, where his cousin already lives. List the push and pull factors.
Push: drought, low farm income. Pull: factory job, higher wages, family already in the city.
4. Why do cities flood more quickly than the countryside after heavy rain?
Concrete, roofs and roads are impermeable, so rain cannot soak into the soil. It runs off quickly into drains, which overflow, and rivers rise fast (flash floods). Blocked drains from waste make it worse.
Common mistakes
- Mixing up urbanisation with urban growth. A city's population can grow while the urban share of the country stays the same if the rural population grows too.
- Saying all urban growth comes from migration. Natural increase is also a big cause, especially in Africa and Asia.
- Thinking slums have no economy. Informal settlements often have many small businesses and jobs; the problem is lack of services and security.
- Believing rich countries are still urbanising fast. Their share is already high and growth is slow; some areas even see counter-urbanisation.