Rate & Rise of Megacities (Edexcel IGCSE Geography)

Factors Affecting the Rate of Urbanisation

• The main factors affecting the rate of urbanisation are:
  • Speed of economic development
    • Economic growth drives urbanisation
    • The faster the growth of secondary and tertiary employment sectors, the faster the growth of urbanisation
  • Rate of population growth
    • Economic growth needs a supply of labour
    • This demand can be met in two ways:
      • Natural increase in urban population - a slow way of meeting demand
      • Rural-urban migration - this is the more important source of labour as it attracts a wider pool of people into the urban region

• Megacities are urban regions with over 10 million residents   
• In 2007, more people lived in an urban environment than a rural one
• By 2050 it is thought that more than two-thirds (7 billion) of the world population will live in urban areas
• This scaling up of the urban environment is the fastest in human history
• Largest growth of megacities is seen in Asia

Reasons for Growth

• Four main factors for growth:
  • Economic development
    • Encourages population growth which leads to the desirability of goods and services
    • All megacities act as service centres within the formal economic sector
    • However, megacities in developing and emerging countries are also important manufacturing centres (Mumbai in India or Dhaka in Bangladesh) with thousands working in the informal economy
  • Population growth
    • Young people are drawn to live in megacities with their vibrancy, fast pace and opportunities
    • There is also ‘internal growth’ where people who have moved into the cities have children, so sustaining population growth (Mexico City, Mumbai, Pearl River Delta in China)
  • Economies of scale
    • Cheaper to provide goods and services in one place than spread across several cities
    • Financial savings for local governments in respect of infrastructure provision
    • Communication and transport are centralised, making savings in time and money
  • Multiplier effect
    • As a city prospers, it acts as a beacon to people and businesses 
    • This encourages inward investment
    • This leads to yet more development and growth
    • Generating further need for skills and labour and job growth
    • This cycle multiplies the positive effects and growth continues (San Francisco and the digital development)

World Cities

• Megacities have a powerful attraction for people and businesses 
• They are influential cores with large peripheries
• World or global cities can be any size but exert particular influences around the globe
• They are considered prestigious, with status and power  
• They are critical hubs in the global economy
• The three top (alpha) world cities are London, New York, and Tokyo 
• These are the financial centres of the world, each with smaller networks of world cities feeding into them
• There are only four world cities in the southern hemisphere:  
  • Sydney
  • Rio de Janeiro
  • Sao Paulo
  • Buenos Aires