Aconurbation is a region consisting of a number ofmetropolises, cities, large towns, and otherurban areas which, throughpopulation growth and physical expansion, have merged to form one continuous urban or industrially developed area. In most cases, a conurbation is apolycentric urbanised area in which transportation has developed to link areas. They create a single urbanlabour market ortravel to work area.[1]
Conurbations often emerged incoal-mining regions during the period of theIndustrial Revolution.[2]Patrick Geddes coined the term in his bookCities in Evolution (1915). He drew attention to the ability of the new technology at the time of electric power and motorised transport to allow cities to spread and agglomerate together, and gave as examples "Midlandton" in England, theRuhr in Germany,Randstad in the Netherlands, and theNortheastern Seaboard in the United States.[3]
For census purposes, the term as described is used in Britain, whereas in the United States a related concept ofmetropolitan area is used instead. Each polycentric "metropolitan area" may have its own common designation such asSan Francisco Bay Area or theDallas–Fort Worth metroplex. Internationally the term "urban agglomeration" is often used to convey a similar meaning to "conurbation".[4][5]
A conurbation is different from amegalopolis in that the urban areas of a megalopolis are close but not physically contiguous, and labor markets have not yet merged. The region structure should also be contrasted with amegacity, as a megacity is hierarchical with a dominant urban core, whereas a conurbation is polycentric and no single urban centre has the dominant role over all other centres.
InRabat-Salé-Kénitra administrative region, the capital city ofRabat and the city ofSalé, both located at the mouth of the riverBou Regreg, form a conurbation.[6]
Lagos is a conurbation formed through the merged development of the initial Lagos city area with other cities and towns includingIkeja andOjo. Also various suburban communities such asAgege,Alimosho,Ifako-Ijaiye,Kosofe,Mushin,Oshodi, andShomolu are included in the area.[7]
The city ofDhaka is linked withNarayanganj andGazipur City; there are no gaps betweenDhaka and the two cities. This conurbation which consists of the areas of the city ofDhaka and its surrounding cities and towns is collectively knowns as theGreater Dhaka City. The city ofDhaka is the core city of the conurbation and has a population of about 10 million. The satellite cities of the conurbation includeNarayanganj,Gazipur,Tongi,Fatullah,Keraniganj,Tarabo, andKaliganj.
TheYangtze River Delta consisting ofShanghai,Nanjing,Hangzhou, andNingbo houses 150 million people and in 2016 it generated $2.76 trillion, 20 percent of China's national GDP. It is responsible for one-third of China's imports and exports.[10]
Greater Jakarta or Jabodetabek comprises the largest urban area in Indonesia and the second-largest in the world with a population of around 30 million.[13] The center and national capital,Jakarta, has a population of 10.3 million within its borders.[14]
The second-most populated city in Indonesia,Surabaya, also forms a conurbation known asGerbangkertosusila with a metropolitan population of about 10 million compared to the city proper of 3 million.[15] Conurbations are also present aroundBandung andMedan.
TheMumbai Metropolitan Region (MMR) consists ofMumbai and its satellite towns. Developing over a period of about 20 years, it consists of seven municipal corporations and fifteen smaller municipal councils. The region has an area of 4,355 km2 and with a population of 20.5 million,[16] and is among the top ten most populated urban agglomerations in the world. It is linked together through the Mumbai Suburban Railway system and a large network of roads.
TheNational Capital Region (NCR) is a name for the coordinated planning region which encompasses the entireNational Capital Territory of Delhi as well as several surrounding districts in the neighbouring states ofUttar Pradesh,Haryana andRajasthan. However, the conurbation of Delhi is actually limited to the NCT of Delhi and the neighbouring contiguous urban areas comprisingGurgaon,Faridabad,Noida,Greater Noida andGhaziabad. The area is officially known as the Central National Capital Region (CNCR), a small part of overall NCR.[17] The population of this conurbation was estimated 21.7 million in 2011.[18] It is the world's third most populous urban agglomeration.
TheAmaravati Metropolitan Region (AMR) ofAndhra Pradesh is a conurbation of three cities, namelyVijayawada,Eluru andGuntur and 11 other towns which includeMangalagiri,Tadepalle,Tenali, Ponnuru, Chilakaluripeta, Narasaraopeta, Sattenapally, Nandigama, Jaggayyapeta, Nuzividu, Gudivada and Vuyyuru. The new capital city of the state,Amaravati, is being developed between the cities of Vijayawada and Guntur at the center of the conurbation. The region holds a total population of 58 lakhs.
The Jamshedpur Metropolitan Area has Greater Jamshedpur and it contains the area and city ofAdityapur,Maango, andJugsalai.
TheRuhr region (Ruhrgebiet) is a majorconurbation located in the federal state ofNorth Rhine-Westphalia. It consists of several large cities of similar size — includingDortmund,Essen,Duisburg,Bochum,Gelsenkirchen, andOberhausen — that have gradually grown together to form a continuous urban area. With no single dominant core city, the Ruhr represents a classicalpolycentric conurbation. It developed as a major coal and steel industrial center during the 19th and 20th centuries, and remains one of the most densely urbanized regions in Europe.
The Ruhr covers an area of approximately 4,438 km2 (1,714 sq mi) and has a population of around 5.1 million people as of 2023.[19] Unlike the broaderRhine-Ruhr metropolitan region, which includes both conurbations and monocentric metropolitan areas such asCologne, the Ruhr region itself is specifically characterized by its polycentric, conurbation structure.
Industrial and housing growth in the United Kingdom during the 19th and early 20th centuries produced many conurbations.Greater London is by far the largest urban area and is usually counted as a conurbation in statistical terms, but differs from the others in the degree to which it is focused on a single central area. In the mid-1950s theGreen Belt was introduced to stem the further urbanisation of the countryside inSouth East England.
TheGolden Horseshoe is a densely populated andindustrialized region centred on the west end ofLake Ontario inSouthern Ontario, Canada. The largest cities in the region areToronto,Mississauga,Brampton,Hamilton,Oakville,Burlington,St. Catharines, andNiagara Falls.[23] If metropolitan areas (which are somewhat distinct from the core urban area of the Golden Horseshoe by about 30 to 50 km of less developed and semi-rural land) are included (similar to Combined Metropolitan Statistical Areas in the United States as defined byUnited States Office of Management and Budget), the total population is 8.8 million people. This is slightly over a quarter (25.6%) of the population of Canada, approximately 75% of Ontario's population, and one of the largest metropolitan areas in North America.[24]
Greater Montreal is Canada's second-largest conurbation.[25]Statistics Canada defines theCensus Metropolitan Area (CMA) as having 4,258.31 square kilometres (1,644.14 sq mi) and a population of 3,824,221 as of2011, which represents almost half of the population of the province ofQuebec. Slightly smaller, there are 82 municipalities grouped under theMontreal Metropolitan Community to coordinate issues such as land planning, transportation, and economic development.
TheNational Capital Region (NCR) is made up of the capital,Ottawa, and neighbouringGatineau which is located across theOttawa River. As Ottawa is inOntario and Gatineau is inQuebec, it is a unique conurbation. Federal government buildings are located in both cities and many workers live in one city and work in the other. The National Capital Region consists of an area of 5,319 square kilometres that straddles the boundary between the provinces of Ontario and Quebec. The area of the National Capital Region is very similar to that of the Ottawa-Gatineau Census Metropolitan Area (CMA) although the National Capital Region contains a number of small neighbouring communities that are not contained within the CMA. When all the communities are included, the population of the area is about 1,500,000. Ottawa-Gatineau is the only CMA in the nation to fall within two provinces and is the fourth largest.[26]
The "CDMX" is the most densely populated center inNorth America.Greater Mexico City refers to the conurbation aroundMexico City, officially called Valley of Mexico Metropolitan Area (Zona Metropolitana del Valle de México), constituted by Mexico City itself composed of 16 Municipalities—and 41 adjacent municipalities of the states ofMexico andHidalgo. However, for normative purposes,[further explanation needed] Greater Mexico City most commonly refers to the Metropolitan Area of the Valley of Mexico (Zona Metropolitana del Valle de México) an agglomeration that incorporates 18 additional municipalities. As of 2019 an estimated 27,782,000 people lived in Greater Mexico City, making it the largest metropolitan area in North America. It is surrounded by thin strips of highlands which separate it from other adjacent metropolitan areas, of which the biggest are Puebla, Toluca, and Cuernavaca-Cuautla. Together those areas make up the Mexico City megalopolis.
The Guadalajara conurbation in the state ofJalisco (colloquially known as the City of Guadalajara, as that is the state capital and most populous of the cities) consists of seven municipalities:Guadalajara,Zapopan,Tlaquepaque,Tonalá,El Salto,Zapotlanejo, andTlajomulco de Zúñiga. Officially two other cities (Juanacatlán andIxtlahuacán de los Membrillos) are also considered part of the Metropolitan Area, although they are not contiguous with the other seven. The area had an estimated population of 4 500 000 in 2010, spread over a combined area of 2,734 square kilometres (1,056 sq mi).[27]
Nocturnal view of theNew York metropolitan area, the world's most brightly illuminated conurbation and largest urban landmass.Long Island extends 120 miles eastward fromManhattan, the central core of the conurbation.
One example of a conurbation is the expansive concept of theNew York metropolitan area (theTri-state region) centered on New York City, including 30 counties spread amongNew York State,New Jersey,Connecticut, andPennsylvania, with an estimated population of 21,961,994 in 2007.[28] Approximately one-fifteenth of all U.S. residents live in the Greater New York City area, the world's most brightly illuminated urban conurbation and largest urban landmass. This conurbation is the result of several central cities whose urban areas have merged.[citation needed]
Holding a population of 7,427,336 as of 2005, the Combined Statistical Area includingGreater Boston consists ofBoston proper and a collection of distinct but intertwined cities includingProvidence, Rhode Island;Worcester, Massachusetts; andManchester, New Hampshire. Most importantly, the cities that compose the Greater Boston CSA are interlinked by heavy public transportation infrastructure, maintain continuously urban interstices, and hold mutual commuting patterns.
Another conurbation is the combination of the metropolitan areas ofSan Francisco,Oakland,San Jose, and several minor urban centers with a combined population of nearly 8 million people, known as theSan Francisco Bay Area.[29]
TheGreater Los Angeles Area consists of the merging of several distinct central cities and counties includingLos Angeles,Orange County,Riverside,San Bernardino, andVentura. The area is also often referred to simply assouthern California or colloquially as SoCal (a larger region which includesSan Diego). In 2016, Southern California had a population of 23,800,500, making it slightly larger than the New York Tri-State Area, and is projected to remain so due to a faster growth rate. But because southern California is not yet a recognized Combined Statistical Area by theUnited States Office of Management and Budget, the New York Tri-State Area officially remains the nation's largest as of now.
The largest conurbation between the United States andMexico isSan Diego–Tijuana. It includes the two countries' busiest border crossing and a shared economy.[30]
Three large cities—Dallas,Fort Worth, andArlington—make up this area. Each city is linked by bordering city limits or suburbs. The area is also known as the Dallas–Fort Worth "metroplex", so called because it has more than one principal anchor city of nearly equal size or importance, and is included in the emerging megalopolis known as theTexas Triangle. According toTexas Monthly, the term is aportmanteau of the terms "metropolitan" and "complex"[31] and was created by a local advertising agency, TracyLocke.[31] The North Texas Commissiontrademarked the term "Dallas/Fort Worth Metroplex" in 1972 as a replacement for the previously ubiquitous term "North Texas".[32] Urban areas with smaller secondary anchor cities (includingMexico City,New York City,Los Angeles,Houston,Chicago, andPhoenix) are not considered to be conurbations.[citation needed]
The major U.S. city ofDetroit lies immediately across theDetroit River fromWindsor, Ontario in Canada. In many respects—economically, historically, culturally, socially, and geographically—Windsor is more a part ofMetro Detroit than of Ontario. The two cities and their surrounding suburbs are commonly referred to collectively as theDetroit–Windsor area. The Detroit-Windsor border is the largest commercial border crossing in North America and the busiest between the two countries.[33]
The entire tri-county area also known as theMiami-Fort Lauderdale-West Palm Beach metropolitan area is now continuously urbanized along a roughly 100 miles (161 km) length of theFlorida east coast as well as extending inland and continuing south of Miami as far asFlorida City. Although this is generally all referred to as a single metropolitan area, not a conurbation, it is sometimes broken up into theMiami,Fort Lauderdale, andWest Palm Beach metros.
Minneapolis–Saint Paul is the most populous urban area in the state ofMinnesota, and is composed of 182 cities and townships built around the Mississippi, Minnesota, and St. Croix rivers. The area is also nicknamed theTwin Cities for its two largest cities,Minneapolis, with the highest population andSaint Paul, the state capital.
TheQuad Cities is a metropolitan area located along the border ofIllinois andIowa. Straddling theMississippi River as it flows west, the area once known as the "Tri Cities" consists of a handful of larger cities and smaller municipalities that have grown together. The largest cities includeRock Island,Moline, andEast Moline in Illinois as well asDavenport andBettendorf in Iowa.
Hartford is the capital city of Connecticut and fourth largest by population. Together, withWaterbury,New Haven,Bridgeport, andStamford, these five cities form a conurbation, as people continue moving into the suburbs of these cities from rural areas, and the Boston and New York City metropolitan areas. Majority of Connecticut's growth in the last decade was centered in and around these five cities. Combined, the population exceeds 1 million.
Denver is the capital and most populous city inColorado, as well as the most populous municipality in theFront Range Urban Corridor. This conurbation encompasses 18 counties in Colorado andWyoming and had an estimated population of 4,976,781 in 2018, an increase of 14.84% since the2010 United States census.[34]
Albury andWodonga are cross border cities which are geographically separated by theMurray River. Albury on the north of the river is part ofNew South Wales, while Wodonga on the south bank is inVictoria. In the early 1970sAlbury-Wodonga was selected as the primary focus of theWhitlam government's scheme to arrest the uncontrolled growth of Australia's large metropolitan areas (in particularSydney andMelbourne) by encouragingdecentralisation.[35] The two cities combine to form an urban area with an estimated population of 93,603.[36]
A cross border built-up area comprising the nation's capitalCanberra in theAustralian Capital Territory and the city ofQueanbeyan in New South Wales, which is considered by the Australian Bureau of Statistics to have a single labour market.[37]
This conurbation inNew South Wales extends fromNewcastle and surrounding satellite towns of theHunter Valley through theCentral Coast. It is broken up only by waterways and national parks, through to the greaterSydney metropolitan area and theWollongong urban area. The total length from the top to the bottom of the conurbation is around 270 km with a population of just over 6 million people.[38]
Plans for makingWollongong, Sydney and Newcastle a single city have been around since the 1960s. A report titledThe Committee for Sydney contains a chapter calledThe Sandstone Mega-Region, Uniting Newcastle, the Central Coast, Sydney, Wollongong (since all of the cities are in a geological region called theSydney Basin, which is made up ofSydney sandstone). The report says that the link would benefit the "six cities" within the region, which are:Illawarra and Wollongong, the Western City (Greater Western Sydney), the Central City (Parramatta), the Eastern City (Sydney central business district,eastern suburbs, andNorthern Sydney), the Central Coast (Gosford) and Newcastle (includingLake Macquarie).[39]
ThePerth Metropolitan Region, andPeel regions form a continuous urban area inWestern Australia more than 130 km (80 miles) long, on a north–south axis. It is sometimes known asGreater Perth and has a population of more than 2.3 million (2023).[40] Introduction of theMandurah railway line in 2007 made it possible for commuters to travel the 70 km (43.5 mi) fromMandurah toPerth in 51 minutes.
Broader definitions ofSouth East Queensland are also used, including the separate built-up area ofToowoomba (140 kilometres; 87 miles west ofBrisbane), which is not part of the Translink network. Expansive definitions of South East Queensland give it a population of more than 3.4 million people (2014),[42] covers 22,420 square kilometres (8,660 sq mi), incorporates ten LGAs, and extends 240 kilometres (150 mi) fromNoosa in the north to the Gold Coast (some sources includeTweed Heads).
In 2010Auckland became a unitary authority encompassing seven former city and district councils includingAuckland City,Manukau City,North Shore City andWaitakere City as well as a number of smaller towns, rural area and the islands of theHauraki Gulf.Auckland Council is the largest council in Australasia and the region has a population of 1,529,300, being almost 33% of the total population ofNew Zealand. The entire urban area rather than the constituent administrative city was often referred to as "Auckland" by New Zealanders long before formal recognition.
TheWellington Metropolitan Area compromises the four cities ofWellington City,Porirua and the cities ofLower Hutt andUpper Hutt, together known asHutt Valley. The Wellington Metropolitan Area is the second largest urban population in New Zealand with a population of 440,900 as of the 2023 census (or 550,500 if the Wairarapa region is included), followed byChristchurch City at 396,200.[43]
The entire Rio–São Paulo area is also sometimes considered a conurbation, and plans are in the works to connect the cities with ahigh-speed rail.[45][46] However the government of Brazil does not consider this area a single unit for statistical purposes, and population data may not be reliable.
Lima is expected to become amegacity before the end of the decade, and this conurbation is estimated to have grown by over one million people between 2007 and 2017.
^"Sale, Morocco".Encyclopedia2.thefreedictionary.com.Salé – a city on the Atlantic coast of Morocco, at the mouth of the Bou Regreg River; part of the capital city conurbation (Rabat-Salé Prefecture). Population, 155,600 (1971).
^Baker, Deane-Parker (15 September 2010). "South Africa's threat environment: a guide for the National Planning Commission".African Security Review.19 (3):54–64.doi:10.1080/10246029.2010.519878.ISSN1024-6029.S2CID144412546....what military force would relish tackling Johannesburg, Ekurhuleni (the East Rand) and Tshwane (greater Pretoria), which will by 2015 be a single polycentric urban region...
^Younger, John Scott; Parry, David Emlyn; Lubis, Harun A.; McLernon, Andrew; Wignall, David John; Hasan, Danni; Benton, Gordon G. (December 2015). "Greater Jakarta, the world's second largest conurbation – part 1".Proceedings of the Institution of Civil Engineers - Municipal Engineer.168 (4):253–261.doi:10.1680/jmuen.14.00050.
^Grant, Jane; Walker, Paul; Nichols, David (2014).What's it all About, Monarto?: John Andrews, Boris Kazanski and the centre of South Australia's unbuilt second "new town"', in Landscapes and Ecologies of Urban and Planning History. Wellington: Australasian Urban History / Planning History Group and Victoria University of Wellington. pp. 255–269.