An urban area, or built-up area, is a human settlement with a high population density and infrastructure of built environment. Urban areas are created through urbanization and are categorized by urban morphology as cities, towns, conurbations or suburbs. In urbanism, the term contrasts to rural areas such as villages and hamlets; in urban sociology or urban anthropology it contrasts with natural environment. The creation of early predecessors of urban areas during the urban revolution led to the creation of human civilization with modern urban planning, which along with other human activities such as exploitation of natural resources led to a human impact on the environment. "Agglomeration effects" are in the list of the main consequences of increased rates of firm creation since. This is due to conditions created by a greater level of industrial activity in a given region. However, a favorable environment for human capital development would also be generated simultaneously.
The world's urban population in 1950 of just 746 million has increased to 3.9 billion in the decades since. 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. This was the first time that the majority of the world's population lived in a city. In 2014 there were 7.2 billion people living on the planet, of which the global urban population comprised 3.9 billion. The Population Division of the United Nations Department of Economic and Social Affairs at that time predicted the urban population would grow to 6.4 billion by 2050, with 37% of that growth to come from three countries: China, India and Nigeria.
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.
Unlike an urban area, a metropolitan area includes not only the urban area, but also satellite cities plus intervening rural land that is socio-economically connected to the urban core city, typically by employment ties through commuting, 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. The last concept is also known as "built-up area in road safety". According to the definition by the Office 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.
European countries[which?] define urbanized areas on the basis of urban-type land use, not allowing any gaps of typically more than 200 metres (220 yd), and use satellite 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.
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, when its cities will house a combined population of over one billion. The country's urbanization rate increased from 17.4% to 46.6% between 1978 and 2009. Between 150 and 200 million migrant workers work part-time in the major cities, returning home to the countryside periodically with their earnings.
Today, China has more cities with one million or more long-term residents than any other country, including the three global cities of Beijing, Hong Kong, and Shanghai; by 2025, the country will be home to 221 cities with over a million inhabitants. 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; the figures below include only long-term residents.
In Japan urbanized areas are defined as contiguous areas of densely inhabited districts (DIDs) using census enumeration districts as units with a density requirement of 4,000 inhabitants per square kilometre (10,000/sq mi).
For the Census of India 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.
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).
In Pakistan, an area is a major city and municipality if it has more than 100,000 inhabitants according to census results. Cities include adjacent cantonments. Urbanisation in Pakistan has increased since the time of independence and has several different causes. The majority of southern Pakistan's population lives along the Indus River. Karachi is its most populous city. In the northern half of the country, most of the population lives in an arc formed by the cities of Lahore, Faisalabad, Rawalpindi, Islamabad, Gujranwala, Sialkot, Gujrat, Jhelum, Sargodha, Sheikhupura, Nowshera, Mardan and Peshawar. 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. Karachi is the most populated city in Pakistan closely followed by Lahore according to the 2017 Census.
In Bangladesh, there are total 532 urban areas, which are divided into three categories. Those are City Corporation, Municipal Corporation (Pourasova) and Upazila town. Among those urban areas, Dhaka is the largest city by population and area, with a population of 19.10 million. In Bangladesh, there are total 11 City Corporations and 329 Municipal Corporations and 203 Small towns, which serves as the center for Upazilas. According to 2011 population census, Bangladesh has an urban population of 28%, with a growth rate of 2.8%. At this growth rate, it is estimated that the urban population of Bangladesh will reach 79 million or 42% of total population by 2035.
With an estimated population of 16.3 million, Metro Manila is the most populous metropolitan area in the Philippines and the 11th in the world. However, the greater urban area is the 5th largest in the world with a population of 20,654,307 people (2010 estimate).
In Vietnam, there are 6 types of urban areas:
As in other Nordic countries, an urban area (taajama in Finnish) in Finland must have a building at least every 200 m (660 ft) and at least 200 people. To be considered a town or a city (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 by municipalities.
In France, an urban area (Fr: aire urbaine) is a zone encompassing an area of built-up growth (called an "urban unit" (unité urbaine) – close in definition to the North American urban area) and its commuter belt (couronne). Americans would find the INSEE definition of the urban area to be similar to their metropolitan area, and the INSEE sometimes uses the term aire métropolitaine to refer to the country's largest aires urbaines.
The largest cities in France, in terms of urban area population (2017), are Paris (12,628,266), Lyon (2,323,221), Marseille (1,760,653), Toulouse (1,360,829), Bordeaux (1,247,977), Lille (1,191,117), Nice (1,006,201), Nantes (972,828), Strasbourg (790,087) and Rennes (733,320).
Germany has a number of large cities. The largest conurbation is the Rhine-Ruhr region (11 million in 2008[update] ), including Düsseldorf (the capital of North Rhine-Westphalia), Cologne, Bonn, Dortmund, Essen, Duisburg, and Bochum.
The Netherlands is the 30th 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. The Randstad is the country's largest conurbation located in the west of the country and contains the four largest cities: Amsterdam, Rotterdam, The Hague, and Utrecht. The Randstad has a population of 7 million inhabitants and is the 6th largest metropolitan area in Europe.
Urban areas in Sweden (tätorter) are statistically defined localities, totally independent of the administrative subdivision of the country. There are 1,956 such localities in Sweden, with a population ranging from 200 to 1,372,000 inhabitants.
The United Kingdom's Office for National Statistics has produced census results from urban areas since 1951, since 1981 based upon the extent of irreversible urban development indicated on Ordnance 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. The UK has five Urban Areas with a population over a million and a further sixty nine with a population over one hundred thousand.
Statistics 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.
In Poland, 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. On the other hand, the Upper Silesian Industrial Region covers 3,200 km and has approximately 3 million people.
Moscow, the capital and largest city of Russia, has a population estimated at 12.4 million residents within the city limits, while over 17 million residents in the urban area, and over 20 million residents in the Moscow Metropolitan Area. It is among the world's largest cities, being the most populous city entirely within Europe, the most populous urban area in Europe, the most populous metropolitan area in Europe, and also the largest city by land area on the European continent. Saint Petersburg, the cultural capital, is the second-largest city, with a population of roughly 5.4 million inhabitants. Other major urban areas are Yekaterinburg, Novosibirsk, Kazan, Nizhny Novgorod, and Chelyabinsk.
In Australia, urban areas are referred to as "urban centres" and are defined as population clusters of 1,000 or more people, with a density of at least 200/km2 (518/sq mi) 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.
Statistics New Zealand defines urban areas in New Zealand, which are independent of any administrative subdivisions and have no legal basis. There are three classes of urban area: main urban areas are the 17 urban areas which have a population of 30,000 or more; secondary urban areas are the 14 urban areas which have a population of 10,000 or more but less than 30,000, and minor urban areas are the 103 urban areas which have a population of 1,000 or more but less than 10,000. Urban areas are reclassified after each New Zealand census, so population changes between censuses does not change an urban area's classification.
According to Statistics Canada, an urban area in Canada 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). 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 cross census metropolitan area or census agglomeration boundaries.
In the Canada 2011 Census, Statistics Canada redesignated urban areas with the new term "population centre"; 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). 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 the United States, there are two categories of urban area. The term urbanized area denotes an urban area of 50,000 or more people. Urban areas under 50,000 people are called urban clusters. Urbanized areas were first delineated in the United States in the 1950 census, while urban clusters were added in the 2000 census. There are 1,371 urban areas and urban clusters with more than 10,000 people.
The U.S. Census Bureau defines an urban area as "core census block groups or blocks that have a population density of at least 1,000 people per square mile (386 per square kilometer) and surrounding census blocks that have an overall density of at least 500 people per square mile (193 per square kilometer)".
The largest urban area in the United States is the New York metropolitan area. The population of New York City, the core of the metropolitan area, exceeds 8.5 million people, its metropolitan statistical area has a population that is over 20 million, and its combined statistical area population is over 23 million. The next seven largest urban areas in the U.S. are Los Angeles, Chicago, Miami, Philadelphia, San Francisco, Houston, and Atlanta. About 82 percent of the population of the United States lives within the boundaries of an urbanized area as of December, 2010. Combined, these areas occupy about 2 percent of the land area of the United States. Many Americans live in agglomerations of cities, suburbs, and towns that are adjacent to a metropolitan area's largest city.
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 of Greenville, South Carolina has a city population just over 68,000 and an urbanized area population of around 400,000, while Greensboro, 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 the U.S. Department of Agriculture's natural resources inventory, urban areas are officially known as developed 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.
Argentina is highly urbanized. 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 the Greater 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.
Córdoba has around 1.5 million people living in the urban area, while Rosario, Mendoza and Tucumán have around 1.2 million inhabitants each and La Plata, Mar del Plata, Salta and Santa Fe have at least 500,000 people each.
According to IBGE (Brazilian Institute of Geography and Statistics) urban areas already concentrate 84.35% of the population, while the Southeast region remains the most populated one, with over 80 million inhabitants. The largest metropolitan areas in Brazil are São Paulo, Rio de Janeiro, and Belo Horizonte — all in the Southeastern Region — with 21, 12, and 5 million inhabitants respectively. In general, state capitals are the largest cities in their states, except for Vitória, the capital of Espírito Santo, and Florianópolis, the capital of Santa Catarina. There are also non-capital metropolitan areas in the states of São Paulo (Campinas, Santos and the Paraíba Valley), Minas Gerais (Steel Valley), Rio Grande do Sul (Sinos Valley) and Santa Catarina (Itajaí Valley).