Urban growth
- Urbanisation is the increase in the proportion of people living in towns and cities. Over half the world's people now live in urban areas.
- It is fastest in lower-income countries in Africa and Asia, because of rural-urban migration and natural increase.
- People leave the countryside because of few jobs, poor services and failed harvests (push factors), and move to cities for jobs, schools and hospitals (pull factors).
- A megacity has more than 10 million people, such as Tokyo, Delhi or Lagos.
Problems in growing cities
- Many new arrivals live in squatter settlements (slums), such as the favelas of Brazil: homes built illegally from scrap materials, often without clean water, sanitation or electricity.
- Many people work in the informal sector, such as street selling, with no contracts or taxes.
- Growing cities face traffic congestion, air pollution and pressure on water and waste services.
Cities in richer countries
- A typical city has a central business district (CBD) of shops and offices, an inner city of older housing and industry, suburbs, and a rural-urban fringe at the edge.
- Counter-urbanisation is when people move out of cities to smaller towns and the countryside.
- Regeneration improves run-down areas. Building on brownfield sites (land used before) protects greenfield sites (land never built on).
- Sustainable cities have good public transport, cycle lanes, green spaces, renewable energy and recycling.
Key terms
- Urbanisation
- The increase in the proportion of people living in towns and cities.
- Rural-urban migration
- People moving from the countryside to cities.
- Megacity
- A city with more than 10 million people.
- Squatter settlement
- An area of poor housing built illegally on land people don't own.
- Informal sector
- Jobs that aren't officially recorded or taxed.
- CBD
- The central business district, with shops and offices.
- Suburbs
- Residential areas towards the edge of a city.
- Counter-urbanisation
- People moving out of cities to the countryside.
- Brownfield site
- Land that has been built on before.
- Greenfield site
- Land that has never been built on.
- Sustainable city
- A city that meets people's needs without harming the environment for the future.