Agglomeration

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An example of an Agglomeration is the San Diego-Tijuana metropolitan area. The cities together create a bi-national agglomeration between Mexico and the United States.

In the study of human settlements, an agglomeration is an extended city or town area comprising the built-up area of a central place (usually a municipality) and any suburbs linked by continuous urban area. In France, INSEE the French Statistical Institute, translate it as "Unité urbaine" which means continuous urbanized area. However, because of differences in definitions of what does and does not constitute an "agglomeration", as well as variations and limitations in statistical or geographical methodology, it can be problematic to compare different agglomerations around the world. It may not be clear, for instance, whether an area should be considered to be a satellite and part of an agglomeration, or a distinct entity in itself.

The term "agglomeration" can also be linked to "Conurbation," which is a more specific term for large urban clusters where the built-up zones of influence of distinct cities or towns are connected by continuous built-up development (Essen - Dortmund and others in the Rhine-Ruhr district), even in different regions, states or countries, Lille - Kortrijk in France and Belgium). Each city or town in a conurbation may nevertheless continue to act as an independent focus for a substantial part of the area.

[edit] Metropolitan Area : Extended definition

It's an extended agglomeration or conurbation that also includes peripheral areas not themselves necessarily urban in character but closely bound to the urban area by flows linked to employment or commerce (see "Aire Urbaine" in France or "agglomération" in Switzerland which take into account at least 40% of flows from outlying areas to ventral built up area, or agglomeration). The population may easily travel within an agglomeration by car or mass transit system. Example: if one lives a thirty minute local rail trip away from downtown New York City, and officially lives in a separately-named smaller county or state outside the city limits, that district or town would be considered a part of the New York agglomeration.

[edit] Metropolitan Area : Administrative definition

The agglomeration can also consist of legal administrative divisions where data is easily available because coming from one administrative level (Metro Area, City, Town, County, ...) The Greater Tokyo Area provides an example of the difficulties involved because estimates of its population vary according to how it is defined. While the prefectures of Tokyo, Chiba, Kanagawa and Saitama are commonly used to define Greater Tokyo, the Japan Statistics Bureau simply measures the area within 50 kilometers of the Tokyo Metropolitan Government Offices in Shinjuku[1] [2].

[edit] Specific legal definitions

[edit] Quebec

Main article: Urban agglomerations of Quebec

An agglomeration, or urban agglomeration, is an administrative subdivision of Quebec at the local level that may group together a number of municipalities which were abolished as independent entities on 1 January 2002 but reconstituted on 1 January 2006.

The eleven agglomerations of Quebec, under this legal definition, range in population from 2,000 to 2 million. In fact, only the agglomerations of Montreal, Quebec, and Longueuil exceed 12,000 inhabitants.

Agglomerations are administered by agglomeration councils, and comprise a central municipality as well as a number of related municipalities, and their powers are defined by the Act respecting the exercise of certain municipal powers in certain urban agglomerations. Agglomerations have certain powers which, elsewhere in Quebec, are exercised by individual municipalities. (These powers are not the same as those of the metropolitan communities of Montreal and Quebec, which cover geographically larger areas than the corresponding agglomerations.) In some cases, agglomerations also have powers ordinarily exercised by regional county municipalities.

[edit] Largest Urban Agglomerations

The term "agglomeration" is more appropriate for determining the populations of large super-cities like Tokyo, Mexico City, and Seoul. These examples are super-cities which have expanded enough to consume other neighborhoods. Although administration may be separate for outlying districts, the population might say they are from the central city.

There are various lists of agglomeration populations. Two are presented here.

According to one list (11.22.06), the largest agglomerations in the world are as follows :

(The above information was gathered from: [3])

Another list indicates substantially smaller populations for some urban agglomerations in 2007. This list uses a “build up” method of population estimation of administrative jurisdictions within the confines of the continuously built up area (except where a census authority estimate is available). The principal difference between the population figures in the two lists is that the first list substitutes metropolitan area populations in urban agglomerations such as New York, Los Angeles, Mexico City, Mumbai and Delhi, which explains the higher figures.

Currently (2007), the agglomerations of more than 10,000,000 area are as follows :

(The above information is modeled for 2007 from population growth rates and is from [4] and [5]. The Manila figure is considerably higher than most lists, which limit their data to the administrative boundaries of Metro Manila. However, the continuous urbanization extends into Cavite, Laguna, Rizal and Bulacan provinces and is reflected in the higher figure in this list.)

Businesses can also "agglomerate" when they need to be in close contact (for example, Financial Services).

[edit] See also

• Economies of agglomeration
• City
• Largest cities of the world - A list of the largest municipalities (cities) areas by population
• Megacity
• Metropolis
• Metropolitan Area
• World city

[edit] External links

• Principal Agglomerations of the World
• A Dynamic Map of the World Cities' Growth