Urban growth

Urbanisation means an increase in the proportion of people living in urban areas compared to rural areas.

The world's population is growing rapidly and reached 7.3 billion people in 2011. The highest rates of population growth are occurring in low income countries (LICs), such as Zimbabwe, Malawi and Niger. Some countries are experiencing population decline, for example Japan, Russia and Ukraine.

Today more than 50% of the world's population live in urban areas. The number of cities with over 10 million people is increasing. These are called megacities. There are now 34 megacities in the world. The table shows the top 10 megacities.

RankUrban areaCountryPopulation estimate
5Seoul-IncheonSouth Korea23,480,000
9New YorkUnited States20,630,000

(Demographia World Urban areas 2015)

The world's biggest megacities are concentrated in Asia.Growth of megacities worldwide

Causes of urban growth

The population of cities usually changes in one of two ways:

  1. Natural increase (or decrease) - this is the difference between the number of births and the number of deaths.
  2. Migration - this is the movement of people into or out of the city.

More and more people are leaving rural areas and moving to cities. This is called rural to urban migration. People move because of push and pull factors. Push factors are things that make people want to leave rural areas and pull factors are the things that attract people to the city.

Push factors: poor security, hazardous environment, war, poverty, basic services. Pull factors: good security, pleasant environment, political stability, good economics, developed services.

Push factors

  • unemployment
  • lower wages
  • crop failure
  • poor living conditions
  • poor health and education services
  • few facilities
  • natural disasters
  • civil war

Pull factors

  • more jobs
  • higher wages
  • better living conditions
  • better education and health services
  • better facilities
  • less chance of natural disasters