Metropolitan area

Metropolitan area in Western Tokyo as seen from Tokyo Tower
A 3D rendered image of the San Diego-Tijuana metropolitan area, a bi-national urban agglomeration.

A metropolitan area is a large population center consisting of a large metropolis and its adjacent zone of influence, or of more than one closely adjoining neighboring central cities and their zone of influence. One or more large cities may serve as its hub or hubs, and the metropolitan area is normally named after either the largest or most important central city within it.

Contents

General definition

A metropolitan area usually combines an agglomeration (the contiguous built-up area) with peripheral zones not themselves necessarily urban in character, but closely bound to the center by employment or commerce; these zones are also sometimes known as a commuter belt, and may extend well beyond the urban periphery depending on the definition used. It is mainly the area that is not part of the city but is connected to the city. For example, Pasadena, California would be added to Los Angeles, California's metro area. While it isn't the same city, it is connected.

The core cities in a polycentric metropolitan area need not be physically connected by continuous built-up development, distinguishing the concept from conurbation, which requires urban contiguity. In a metropolitan area, it is sufficient that central cities together constitute a large population nucleus with which other constituent parts have a high degree of integration.

In practice the parameters of metropolitan areas, in both official and unofficial usage, are not consistent. Sometimes they are little different from an urban area, and in other cases they cover broad regions that have little relation to the traditional concept of a city as a single urban settlement. Thus all metropolitan area figures should be treated as interpretations rather than as hard facts. Metro area population figures given by different sources for the same place can vary by millions, and there is a tendency for people to promote the highest figure available for their own "city". However the most ambitious metropolitan area population figures are often better seen as the population of a "metropolitan region" than of a "city".

Differences in terminology by country

The term metropolitan area is sometimes abbreviated to 'metro', for example in Metro Manila and Washington, DC Metro Area, which in the latter case should not be mistaken to mean the metro rail system of the city. Although it can be compared in composition to many of the world's metropolitan areas, in France the term for the region around an urban core linked by commuting ties is an aire urbaine (officially translated as "urban area"). In Japan that would be toshiken (都市圏? lit. bloc of cities).

Country official unique definitions

Australia

Perth is arguably the most isolated metropolitan area in the world.

In Australia, Statistical Divisions (SDs) are defined by the Australian Bureau of Statistics as areas under the unifying influence of one or more major towns or cities. Each capital city forms its own Statistical Division, and the population of the SD is the most-often quoted figure for that city's population. Statistical Districts are defined as non-capital but predominantly urban areas. The statistical divisions that encompass the capital cities are commonly though unofficially called 'metropolitan areas'.[1]

United States

The Office of Management and Budget defines "Core Based Statistical Areas" used for statistics purposes among federal agencies. Each CBSA is based on a core urban area and is composed of the counties which comprise that core as well as any surrounding counties that are tightly socially or economically integrated with it. These areas are designated as either metropolitan or micropolitan statistical areas, based on population size; a "metro" area has an urban core of at least 50,000 residents, while a "micro" area has less than 50,000 but at least 10,000.[2]

Additional terms

At the turn of the 19th century only 3 percent of the world was urbanized. During the 20th and into the 21st century the presence of humans in urban areas has increased dramatically. Within the first quarter of the 21st century it is expected that more than half of the world's population will live in urban areas, if this is not already the case.[3]

By 2025, according to the Far Eastern Economic Review, Asia alone will have at least 10 hypercities, those with 20 million or more, including Delhi (~20 million), Jakarta (24.9 million people), Dhaka (25 million), Karachi (26.5 million), Shanghai (27 million) and Mumbai (33 million).[4] Lagos has grown from 300,000 in 1950 to an estimated 15 million today, and the Nigerian government estimates that city will have expanded to 25 million residents by 2015.[5]

If several metropolitan areas are located in succession, metropolitan areas are sometimes grouped together as a megalopolis (plural megalopoleis, also megalopolises). A megalopolis consists of several interconnected cities (and their suburbs), between which people commute, and which are so close together that suburbs can claim to be suburbs of more than one city. Another name for a megalopolis is a metroplex (short for metropolitan complex) or conurbation.

This concept was first proposed by the French geographer Jean Gottmann in his book Megalopolis, a study of the northeastern United States. One famous example is the BosWash megalopolis consisting of Boston, Providence, Hartford, New York City, Newark, Philadelphia, Wilmington, Baltimore, Washington, and vicinity.

The biggest one is the Taiheiyō Belt (the Pacific Megalopolis) in Japan consisting of Tokyo, Shizuoka, Nagoya, Osaka, Okayama, Hiroshima, Fukuoka and vicinity. The main transportation such as Shinkansen and expressways is constructed along these cities. The population of this megalopolis is around 82.9 million.

Guangdong Province's Pearl River Delta is a huge megalopolis with a population of 48 million that extends from Hong Kong and Shenzhen to Guangzhou. Some projections assume that by 2030 up to 1 billion people will live in China's urban areas. Even rather conservative projections predict an urban population of up to 800 million people. In its most recent assessment, the UN Population Division estimated an urban population of 1 billion in 2050.[6]

The megalopoleis in Europe are the Ruhr Area in Germany, the Randstad (Knooppunt Arnhem-Nijmegen and Brabantse Stedenrij are counted with the Randstad) in the Netherlands, the Flemish Diamond in Belgium, Ile de France in France and the metropolitan area of London, as well as several 'smaller' agglomerations, such as the Meuse-Rhine Euregion, the Ems-Dollart Euregion, the Lille-Kortrijk-Tournai Euregion and Metropoly of Upper Silesia in Poland (17 cities around Katowice with a total population of over 2 million). Together this megalopolis has an estimated population of around 50 million.

Africa's first megalopolis is situated in the urban portion of Gauteng Province in South Africa, comprising the conurbation of Johannesburg, and the metropolitan areas of Pretoria and the Vaal Triangle, otherwise known as the PWV.

It has been suggested that the whole of south-eastern, Midland and parts of northern England will evolve into a megalopolis dominated by London. Clearly when usage is stretched this far, it is remote from the traditional conception of a city.

Megacity is a general term for agglomerations or metropolitan areas which usually have a total population in excess of 10 million people. In Canada, "megacity" can also refer informally to the results of merging a central city with its suburbs to form one large municipality. A Canadian "megacity", however, is not necessarily an entirely urbanized area, as many cities so named have both rural and urban portions. It also doesn't need 10 million inhabitants to bear the designation. Moreover, Canadian "megacities" do not constitute large metropolitan areas in a global sense.

Census population of a metro area is not the city population. However, it better demonstrates the population of the city. Los Angeles may only have a city population of near 4,000,000, but has two metropolitan area populations, depending on definition, 13 million in the core area and 18 million in the Combined statistical area.

See also

Terms

Lists of metropolitan areas

Metropolitan Planning Theories

References

  1. ↑ 1217.0.55.001 - Glossary of Statistical Geography Terminology, 2003, Australian Bureau of Statistics, 2003
  2. ↑ Metropolitan and Micropolitan Statistical Areas, U.S. Census Bureau
  3. ↑ The world goes to town
  4. ↑ Planet of Slums by Mike Davis
  5. ↑ Lagos, Nigeria facts - National Geographic
  6. ↑ China's urban population to reach 800 to 900 million by 2020: expert

External links