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.
General definition
There has been no significant change in the basic metropolitan area
"concept" since its adoption in 1950 , though significant changes
in geographic distributions have occurred since, and is expected to
further evolve through time. Because of the fluidity and evolution
of the "term" metropolitan statistical areas, the colloquial
reference by the general population and media to define an MSA is
with a more familiar reference to "metro service area, metro area,
metro, or MSA" and widely intimated to mean the aggregate
geographic area inclusive of not only a well known city population,
but also its inner city, suburban, exurban and sometimes rural
surrounding populations, all of which are influenced by employment,
transportation, and commerce of the more largely well known urban
city.
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
' metro area. While it isn't the same city,
it is connected, and Pasadena is also located in Los Angeles
County.
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 .
Country official unique definitions
Australia
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'.
European Union
The
European Union's statistical
agency,
Eurostat, has created a concept
named
Larger Urban Zone (LUZ). The
LUZ represents an attempt at a harmonised definition of the
metropolitan area, and the goal was to have an area from a
significant share of the resident commute into the city, a concept
known as the “functional urban region”.
Republic of India
In
India
, the Census Commission defines a metropolitan city
as one having a population of over 40 lakh (4 million).
Mumbai
, Delhi
, Chennai
, Kolkata
, Bengaluru
, Hyderabad
, are the six cities that qualify. Residents
of these cities are also entitled to a higher House rent allowance.
The figure only applies to the city region and not the
conurbation.
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 area, 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.
Additional terms
At the turn of the 19th century only 3 percent of the world's
population 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.
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). 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.
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 Northeast
megalopolis consisting of Boston
, New York City
, Philadelphia
, Baltimore
, Washington
, and their vicinities.
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.
The megalopolises in Europe are the
Milan metropolitan area (pop. 7.4
million) in Italy,
Ruhr Area (pop.
5.3
million) in Germany, the Randstad
(Knooppunt Arnhem-Nijmegen and Brabantse Stedenrij
are counted with the Randstad) in the Netherlands (pop. 7.4
million), the
Flemish Diamond in
Belgium (pop.
5.5 million), Ile de
France
in France and the metropolitan area of London
and Moscow
, 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.
For example, Toronto
has a metropolitan population of 5.5 million but is
part of a much larger metropolitan area home to over 8.1 million
people.
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
-
http://www.census.gov/population/www/metroareas/aboutmetro.html
- http://www.whitehouse.gov/omb/rewrite/fedreg/msa.html
- 1217.0.55.001 - Glossary of Statistical Geography
Terminology, 2003, Australian Bureau of Statistics,
2003
- about LUZ
- Ahmedabad yet to become mega city
- Metropolitan and Micropolitan Statistical
Areas, U.S. Census Bureau
- The world goes to town
- Planet of Slums by Mike Davis
- Lagos, Nigeria facts - National Geographic
- China's urban population to reach 800 to 900
million by 2020: expert
External links
- MetroFYI.com - Partial list of Travel and Tourism
information for North America (All Metros NOT included).
- metropolis.org - An organisation of world
metropolises
- Urban Employment Areas in Japan (Metropolitan
Employment Areas in Japan)
- [11453] (Metropolis read by maps in Friuli Venezia
Giulia - Northeast of Italy - EU)
- Geopolis
: research group, university of Paris-Diderot, France —
Urbanization of the world