Earth's land use in 2019, built-up area being estimated as 1.5 million square kilometers.
In 1950, 764 million people or about 30 percent of the world's 2.5 billion people lived in urban areas. By 2014, it was 3.9 billion or about 53 percent of the world's 7.3 billion people that lived in urban areas. The change was driven by a combination of increased total population and increased percent of population living in urban areas.[4] In 2009, the number of people living in urban areas (3.42 billion) surpassed the number living in rural areas (3.41 billion), and since then the world has become more urban than rural.[5] This was the first time that the majority of the world's population lived in a city.[6] By that time a high estimate calculated up to 3.5 million square kilometers of land were urban, estimates ranging from 1% of global land area.[7][8] In 2014 there were 7.3 billion people living on the planet,[9] of which the global urban population comprised 3.9 billion. The Population Division of theUnited Nations Department of Economic and Social Affairs at that time predicted the urban population would occupy 68% of the world population by 2050, with 90% of that growth coming from Africa and Asia.[10]
Unlike an urban area, ametropolitan area includes not only the urban area, but alsosatellite cities plus intervening rural land that is socio-economically connected to theurban core city, typically byemployment ties throughcommuting, with the urban core city being the primary labor market.
The concept of an "urban area" as used in economic statistics should not be confused with the concept of the "urban area" used in road safety statistics. This term was first created by Geographer Brian Manning. The last concept is also known as "built-up area in road safety". According to the definition by theOffice for National Statistics, "Built-up areas are defined as land which is 'irreversibly urban in character', meaning that they are characteristic of a town or city. They include areas of built-up land with a minimum of 20 hectares (200,000 m2; 49 acres). Any areas [separated by] less than 200 metres [of non-urban space] are linked to become a single built-up area.[12]
Argentina and Japan are countries where the urbanization rate is over 90% while Australia, Brazil, Canada, Chile, Mexico, and the United States are countries where the urbanization rate is between 80% and 90%, although within theU.S. state ofNew Jersey, the urbanization rate is 100%.[13]
There are two measures of the degree of urbanization of a population. The first, urban population, describes the percentage of the total population living in urban areas, as defined by the country. The second measure, rate of urbanization, describes the projected average rate of change of the size of the urban population over the given period of time. According toUrbanization by sovereign state article, the world as a whole is 56.2% urbanized, with roughly one-quarter of the countries reported as greater than 80% urbanized. Data is taken from the U.S. Central Intelligence Agency World Factbook estimates from 2020.[14]
Presently, urban data are based on arbitrary definitions that vary from country to country and from year or census to the next, making them difficult to compare. An Urban Metric System (UMS) has been conceived that could correct the problem,[16] since it allows computing the urban area limits and central points, and it can be applied in the same way to all past, present and future population and job distributions. It is based on vector field calculations obtained by assuming that, in a given space, all inhabitants and jobs exert the same attractive forceA and repulsive forceR. The net force (A -R) exerted by each inhabitant or job is given by [1/(1 +d)] - [1/(β +d/2)], whered = distance andβ is the only parameter. UMS distinguishes the following types of urban areas, each type corresponding to a given value ofβ:
Urban area
Distance at which the attractive force = the repulsive force
Value ofβ
1
Central city
10 km
6
2
Agglomeration
20 km
11
3
Metropolis
40 km
21
4
Patropolis
80 km
41
5
Megalopolis
160 km
81
6
Urban system
320 km
161
7
Urban macrosystem
640 km
321
8
Continental system
1,280 km
641
9
Intercontinental system
2,560 km
1,281
10
World system
5,120 km
2,561
UMS has been applied to some Canadian cases since 2018, but the data presented in this article are still based on the various existing national definitions, which are disparate.
The UN publishes data on cities, urban areas and rural areas, but relies almost entirely on national definitions of these areas. The UN principles and recommendations state that due to different characteristics of urban and rural areas across the globe, a global definition is not possible.[17]
European countries[which?] define urbanized areas on the basis of urban-typeland use, not allowing any gaps of typically more than 200 metres (220 yd), and usesatellite imagery instead of census blocks to determine the boundaries of the urban area. In less-developed countries[which?], in addition to land use and density requirements, a requirement that a large majority of the population, typically 75%, is not engaged in agriculture and/or fishing is sometimes used.[citation needed]
Since 2000,China's cities have expanded at an average rate of 10% annually. It is estimated that China's urban population will increase by 292 million people by 2050,[4] when its cities will house a combined population of over one billion.[18] The country's urbanization rate increased from 17.4% to 46.6% between 1978 and 2009.[19] Between 150 and 200 millionmigrant workers work part-time in the major cities, returning home to the countryside periodically with their earnings.[20][21]
China has more cities with one million or more long-term residents than any other country, including the threeglobal cities ofBeijing, Hong Kong, andShanghai; by 2025, the country will be home to 221 cities with over a million inhabitants.[18] The figures in the table below are from the 2008 census, and are only estimates of the urban populations within administrative city limits; a different ranking exists when considering the total municipal populations (which includes suburban and rural populations). The large "floating populations" of migrant workers make conducting censuses in urban areas difficult;[22] the figures below include only long-term residents.
InJapan, urbanized areas are defined ascontiguous areas of densely inhabited districts (DIDs) usingcensus enumeration districts as units with a density requirement of 4,000 inhabitants per square kilometre (10,000/sq mi).
For the Census ofIndia 2011, the definition of urban area is a place having a minimum population of 5,000 of density 400 persons per square kilometre (1,000/sq mi) or higher, and 75% plus of the male working population employed in non-agricultural activities. Places administered by a municipal corporation, cantonment board or notified town area committee are automatically considered urban areas.[26]
The Census of India 2011 also defined the term "urban agglomeration" as an integrated urban area consisting of a core town together with its "outgrowths" (contiguous suburbs).[27]
InPakistan, an area is a majorcity andmunicipality if it has more than 100,000 inhabitants according to census results.Cities include adjacentcantonments.Urbanisation inPakistan has increased since the time of independence and has several different causes. The majority of southern Pakistan's population lives along theIndus River. Karachi is its most populous city.[30] In the northern half of the country, most of the population lives in an arc formed by the cities ofLahore,Faisalabad,Rawalpindi,Islamabad,Gujranwala,Sialkot,Gujrat,Jhelum,Sargodha,Sheikhupura,Nowshera,Mardan andPeshawar. During 1990–2008, city dwellers made up 36% of Pakistan's population, making it the most urbanised nation in South Asia. Furthermore, 50% of Pakistanis live in towns of 5,000 people or more.[31]Karachi is the most populated city in Pakistan closely followed by Lahore according to the2017 Census.
InBangladesh, there are total 532 urban areas, which are divided into three categories. Those areCity Corporation,Municipal Corporation (Pourasova) andUpazila town. Among those urban areas,Dhaka is the largest city by population and area, with a population of 19.10 million.[32] InBangladesh, there are total 11City Corporations and 329Municipal Corporations and 203Small towns, which serves as the center forUpazilas. According to 2011 population census,Bangladesh has an urban population of 28%, with a growth rate of 2.8%.[33] At this growth rate, it is estimated that the urban population of Bangladesh will reach 79 million or 42% of total population by 2035.
In 2020, 54 percent of the Philippine population lived in urban areas.[34] With an estimated population of 16.3 million,Metro Manila is the most populous metropolitan area in thePhilippines and the11th in the world. However, the greater urban area is the5th largest in the world with a population of 20,654,307 people (2010 estimate).[35]
A street sign inVimpeli indicating the beginning of an urban area in Finland
As in other Nordic countries, an urban area (taajama inFinnish) in Finland must have a building at least every 200 m (660 ft) and at least 200 people. To be considered atown or acity (kaupunki) for statistical purposes, an urban area must have at least 15,000 people. This is not to be confused with the city / town designation used bymunicipalities.[39][40]
InFrance, an urban area (Fr:aire d'attraction d'une ville) is a zone encompassing an area of built-up growth (called an "urban unit" (unité urbaine)[41] – close in definition to the North American urban area) and its commuter belt (couronne). Americans would find theINSEE definition of the urban area[42] to be similar to theirmetropolitan area.
TheNetherlands is the30th-most densely populated country in the world, with 404.6 inhabitants per square kilometre (1,048/sq mi)—or 497 inhabitants per square kilometre (1,287/sq mi) if only the land area is counted. TheRandstad is the country's largestconurbation located in the west of the country and contains the four largest cities: Amsterdam,Rotterdam,The Hague, andUtrecht. The Randstad has a population of 7 million inhabitants and is the6th largestmetropolitan area in Europe.
Norway defines urban areas ("tettsteder")similarly to the other Nordic countries. Unlike in Denmark and Sweden, the distance between each building has to be of less than 50 m, although exceptions are made due to parks, industrial areas, rivers, and similar. Groups of houses less than 400 m from the main body of an urban area are included in the urban area.[45]
InPoland, official "urban" population figures simply refer to those localities which have the status of towns (miasta). The "rural" population is that of all areas outside the boundaries of these towns. This distinction may give a misleading impression in some cases, since some localities with only village status may have acquired larger and denser populations than many many smaller towns[46] with most excessive example ofPoznań, most spread urban area of the country with population of the city app. 534 thousand andmetropolitan area around 1 million inhabitants. On the other hand, theKatowice urban area with numerous large and medium cities covers 1,468 km and has above 2 million people.Themetropolitan areas in Poland are the biggest urban zones (e.g.Katowice metropolitan area,Łódź metropolitan area andSzczecin metropolitan area) and have great impact on the rural surroundings, as it is aroundLublin,Radom,Kielce,Tarnów andBiałystok.
Spain is a very highly urbanized country.Madrid is its largest urban area. The Southern and Eastern coasts withBarcelona,Valencia andMálaga are more urbanised than the Northern and Western ones.
Urban areas in Sweden (tätorter) are statistically defined localities, totally independent of the administrative subdivision of the country. There are 1,956 such localities inSweden, with a population ranging from 200 to 1,372,000 inhabitants.[53]
In 2013 theUnited Kingdom'sOffice for National Statistics (ONS) published2011 Built-up Areas – Methodology and Guidance which sets out its definition of aBuilt-up area (BUA) as an area of built-up land of at least 20 hectares (0.077 sq mi), separated from other settlements by at least 200 metres (660 ft). For 2011 census data there are 5,493 built-up areas, of which 501 are divided intoBuilt-up area sub-divisions (BUASD) for which data is also available. Each built-up area is named algorithmically, using Ordnance Survey place-name data.[54]
The ONS has produced census results from urban areas since 1951, since 1981 based upon the extent of irreversible urban development indicated onOrdnance Survey maps. The definition is an extent of at least 20 ha and at least 1,500 census residents. Separate areas are linked if less than 200 m (220 yd) apart. Included are transportation features.[55] The UK has five Urban Areas with a population over a million and a further sixty nine with apopulation over one hundred thousand.
TheAustralian Bureau of Statistics refers to urban areas as Urban Centres, which it generally defines as population clusters of 1,000 or more people.[59] Australia is one of the most urbanised countries in the world, with more than 50% of the population residing in Australia's three biggest urban centres.[citation needed][59]
Sydney is Australia's largest city, home to 5.3 million inhabitants.[60]
Statistics New Zealand defines urban areas in New Zealand, which are independent of any administrative subdivisions and have no legal basis.[62] There are four classes of urban area: major urban areas (population 100,000+), large urban areas (population 30,000–99,999), medium urban areas (population 10,000–29,999) and small urban areas (population 1,000–9,999). As of 2021, there are 7 major urban areas, 13 large urban areas, 22 medium urban areas and 136 small urban areas. Urban areas are reclassified after eachNew Zealand census, so population changes between censuses does not change an urban area's classification.
According toStatistics Canada, an urban area inCanada is an area with a population of at least 1,000 people where the density is no fewer than 400 persons per square kilometre (1,000/sq mi).[64] If two or more urban areas are within 2 km (1.2 mi) of each other by road, they are merged into a single urban area, provided they do not crosscensus metropolitan area orcensus agglomeration boundaries.[65]
In theCanada 2011 Census, Statistics Canada redesignated urban areas with the new term "population centre";[66] the new term was chosen in order to better reflect the fact that urban vs. rural is not a strict division, but rather a continuum within which several distinct settlement patterns may exist. For example, a community may fit a strictly statistical definition of an urban area, but may not be commonly thought of as "urban" because it has a smaller population, or functions socially and economically as a suburb of another urban area rather than as a self-contained urban entity, or is geographically remote from other urban communities. Accordingly, the new definition set out three distinct types of population centres: small (population 1,000 to 29,999), medium (population 30,000 to 99,999) and large (population 100,000 or greater).[66] Despite the change in terminology, however, the demographic definition of a population centre remains unchanged from that of an urban area: a population of at least 1,000 people where the density is no fewer than 400 persons per km2.
In theUnited States, theCensus Bureau defines urban areas and delineates urban area boundaries after each census. The Bureau defines an urban area as "a statistical geographic entity consisting of a densely settled core created fromcensus blocks and contiguous qualifying territory that together have at least 2,000 housing units or 5,000 persons."[68] There were 2,646 urban areas identified by the Census Bureau for 2020. 511 of these had a population of 50,000 or more.[69]
For the 2000 and 2010 censuses, the Census Bureau differentiated between two kinds of urban areas: urbanized areas and urban clusters. The termurbanized area denoted an urban area of 50,000 or more people. Urban areas under 50,000 people were calledurban clusters. Urbanized areas were first delineated in the United States in the 1950 census, while urban clusters were added in the 2000 census. The distinction between urbanized areas and urban clusters was removed for the 2020 census.[68]
Urban areas consist of a densely-settled urban core, plus surrounding developed areas that meet certain density criteria. Since urban areas are composed of census blocks and not cities, counties, or county-equivalents, urban area boundaries may consist of partial areas of these political units. Urban areas are distinguished fromrural areas: any area not part of an urban area is considered to be rural by the Census Bureau.[68]
The largest urban area in the United States is that ofNew York City and its surrounding suburbs. The New York–Jersey City–Newark, NY–NJ urban area had a population of 19,426,449 as of 2020, while the largermetropolitan area had a population of 20,140,470, and thecombined statistical area had a population of 23,582,649. The next five largest urban areas in the U.S. are those ofLos Angeles,Chicago,Miami,Houston, andDallas.[69] 80.0 percent of the population of the United States lives within the boundaries of an urban area as of the 2020 census.[70]
The concept of Urbanized Areas as defined by the U.S. Census Bureau is often used as a more accurate gauge of the size of a city, since in different cities and states the lines between city borders and the urbanized area of that city are often not the same. For example, the city ofGreenville, South Carolina has a city population just over 68,000 and an urbanized area population of around 400,000, whileGreensboro, North Carolina has a city population just over 285,000 and an urbanized area population of around 300,000 — meaning that Greenville is actually "larger" for some intents and purposes, but not for others, such as taxation, local elections, etc.
In theU.S. Department of Agriculture'snatural resources inventory, urban areas are officially known asdeveloped areas or urban and built-up areas. Such areas include cities, ethnic villages, other built-up areas of more than 10 ac (4 ha), industrial sites, railroad yards, cemeteries, airports, golf courses, shooting ranges, institutional and public administration sites, and similar areas. The 1997 national resources inventory placed over 98,000,000 ac (40,000,000 ha) in this category, an increase of 25,000,000 ac (10,000,000 ha) since 1982.[71]
Argentina is highly urbanized.[72] The ten largest metropolitan areas account for half of the population, and fewer than one in ten live in rural areas. About 3 million people live in Buenos Aires City and theGreater Buenos Aires metropolitan area totals around 15 million, making it one of the largest urban areas in the world, with a population of 18 million all up.[73]
In Brazil, the termsmetropolitan area (Portuguese:região metropolitana) andurban agglomeration (aglomeração urbana) have specific meanings. They are defined by federal and state legislation as collections ofmunicipalities focused on "integrating the organization, planning and execution of public functions of common interest".[75] Anintegrated development area (região integrada de desenvolvimento) is one of the two above structures that crosses state (orFederal District) boundaries.
^Morris, A.E.J. (2 December 2013) [1972]. "The Early Cities".History of Urban Form Before the Industrial Revolution (3 ed.). London: Routledge. p. 1.ISBN9781317885146.[...] the Bronze Age, starting between 3500 and 3000 BC [...]. During this [...] period the first urban civilizations were firmly established.
^Chongqing Statistics Bureau (2019).重庆统计年鉴2019 [Chongqing Statistical Yearbook 2019] (in Chinese). Beijing: China Statistic Publishing House. p. 613.ISBN978-7-5037-8854-3.
^"Agglomerations & Cities".INDIA: States and Major Agglomerations Population Totals. Office of the Registrar General and Census Commissioner. Retrieved2020-03-27.
%2c_OWID.svg)
.jpg)
.jpg)
.jpeg)
.jpg)
.jpg)
