World Resources 1996-97
(A joint publication by The World Resource Institute, The United
 Nations Environment Programme, The United Nations Development
 Programme, and the World Bank)
 (Edited by Dr. Róbinson Rojas)

1. Cities and the Environment


Box 3 What Is an Urban Area?

By the year 2010, well over 3.7 billion people will be classified as urban dwellers--more people than inhabited the world just four decades earlier (1). While some of these urban dwellers will be living in such megacities as Sao Paulo, Brazil, and Shanghai, China, the majority will live in a kaleidoscope of settlements: from large industrial cities to small mercantile towns and villages.

While the term "urban area" is typically used as a synonym for "city," the two are not the same. All cities are urban areas, but not all urban areas are cities. "Urban" is a statistical concept defined by a country's government. A city, on the other hand, is more than just large numbers of people living in close proximity to one another; it is a complex political, economic, and social entity. Cities around the world symbolize their nation's identity and political strength. Cities are also centers of economic production, religion, learning, and culture.

Because each country sets its own definition of "urban," there is a bewildering array of definitions around the world. Governments of small or relatively rural countries may simply declare one or more settlements urban, regardless of size or function (2). In many countries, the definition is based on a threshold number of inhabitants; when the population of a region exceeds a certain threshold, that region is considered urban (3). This threshold ranges from a few hundred, as in Peru and Uganda, to more than 10,000, as in Italy and Senegal (4). Other governments base their definition on a combination of criteria, such as population density, political function, or predominant activity of the region.

These definitional differences can skew international comparisons. If the Indian government adopted Peru's definition of urban, India would suddenly become one of Asia's more urbanized nations (5). This, in turn, would change the regional urbanization levels for South Asia (6).

Even within countries, the definition of urban may vary. In 1990, the World Bank reported that China's urbanization level jumped from 18 to 50 percent between 1965 and 1988 (7). While some of this urban growth could be attributed to economic growth and migration, it is largely explained by the government adopting a new definition of urban in 1986, which included many agrarian communities. Since 1986, China has again changed the definition to be more accurate--in 1990, China's population was considered 26.21 percent urban (8).

Defining urban is further complicated by the dynamic nature of cities. In both developed and developing countries, urban activity tends to move beyond established urban boundaries. Depending on the boundary used, Tokyo's 1990 population could range from 8.2 million people (in the 23 wards of the central city)to 39.2 million people (in the National Capital Region)(9). At night, Tokyo's central city population may actually be much lower, as commuters leave the downtown area for their suburban homes.

For all these reasons, comparisons of urbanization levels, urban growth rates, or city size may be highly misleading (10). In addition, while the United Nations' urban population figures used in this report are the most extensive international data set available, they should nevertheless be viewed only as best estimates.

References and Notes

1. United Nations (U.N.)Population Division, World Urbanization
   Prospects: The 1994 Revision (U.N., New York, 1995), p. 87.

2. Jorge E. Hardoy and David Satterthwaite, "Urban Change in the
   Third World: Are Recent Trends a Useful Pointer to the Urban
   Future?" Habitat International, Vol. 10, No. 3 (1986), p. 34.

3. Ibid. 4. Op. cit. 1, pp. 40, 45þ46, 48þ49.

5. Op. cit. 2.

6. Op. cit. 2.

7. The World Bank, World Development Report 1990 (Oxford University
   Press, New York, 1990), p. 238.

8. United Nations (U.N.)Economic and Social Commission for Asia and
   the Pacific, State of Urbanization in Asia and the Pacific, 1993
   (U.N., New York, 1993), p. 2-2.

9. Roman Cybriwsky, "Tokyo," Cities, Vol. 10, No. 1 (February 1993),
   p. 3.

10. United Nations Centre for Human Settlements (Habitat), An
    Urbanizing World: Global Report on Human Settlements 1996
    (Oxford University Press, Oxford, United Kingdom, and New York,
    1996), p. 1-18.

Table of Contents

Back to Top