Urban area

Greater Tokyo Area, the world's most populous urban area with about 35 million people.

Urban areas with at least one million inhabitants in 2006. In 1800, 3% of the world's population lived in cities, a figure that had risen to 47% by the end of the twentieth century.

World map showing percent of population living in an urban environment.

An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.

Urban areas are created and further developed by the process of urbanization. Measuring the extent of an urban area helps in analyzing population density and urban sprawl, and in determining urban and rural populations (Cubillas 2007).

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. In fact, urbanized areas agglomerate and grow as the core population/economic activity center within a larger metropolitan area or envelope.

Metropolitan areas tend to be defined using counties or county sized political units as building blocks. Counties tend to be stable political boundaries; economists prefer to work with economic and social statistics based on metropolitan areas. Urbanized areas are a more relevant statistic for determining per capita land usage and densities (Dumlao & Felizmenio 1976).

Definitions

They vary somewhat amongst different nations. European countries define urbanized areas on the basis of urban-type land use, not allowing any gaps of typically more than 200 meters, and use satellite imagery instead of census blocks to determine the boundaries of the urban area. In less developed countries, 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.

Skyline of old downtown of São Paulo, Brazil.

Australia

In Australia, urban areas are referred to as "urban centres" and are defined as population clusters of 1000 or more people, with a density of 200 or more persons per square kilometre.^[1]

Canada

Downtown Toronto (an urban area)

In Canada, an urban area is an area that has more than 400 people per square kilometre and has more than 1,000 people. If two or more urban areas are within two kilometres of each other, they are merged into a single urban area. The boundaries of an urban area are not influenced by municipal or even provincial boundaries.^[2]

China

In China, an urban area is an urban district, city and town with a population density higher than 1,500 people per square kilometre. As for urban districts with a population density lower than 1,500 people per square kilometre, only the population that lives in streets, town sites, and adjacent villages is counted as urban population.^[3]

France

Top 25 French urban areas

In France, an urban area is a zone (aire urbaine) encompassing an area of built-up growth (called an "urban unit" (unité urbaine)^[4] - close in definition to the North American urban area) and its commuter belt (couronne périurbaine). Although the official INSEE translation of aire urbaine is "urban area",^[5] most North Americans would find the same as being similar in definition to their metropolitan area.

Japan

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).

New Zealand

Statistics New Zealand defines New Zealand urban areas for statistical purposes as a settlement with a population of a thousand people or more.

Norway

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 meters, although exceptions are made due to parks, industrial areas, rivers, and similar. Groups of houses less than 400 metres from the main body of an urban area are included in the urban area.^[6]

Poland

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 smaller towns.^[7]

Sweden

Urban areas in Sweden (tätorter) are statistically defined localities, totally independent of the administrative subdivision of the country. There are 1,940 such localities in Sweden, with a population ranging from 200 to 1,252,000 inhabitants.^[8]

United Kingdom

The United Kingdom's Office for National Statistics 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 50 acres and at least 1,500 census residents. Separate areas are linked if less than 220 yards apart. Included are transportation features.^[9] The largest urban area is Greater London, followed by the West Midlands county, Greater Manchester, Greater Glasgow and Merseyside.

United States

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 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 under 60,000 but an urbanized area over 300,000, while Greensboro, North Carolina has a city population over 200,000 but an urbanized area population of around 270,000 — meaning that Greenville is actually "larger" for some intents and purposes, but not for others, such as taxation, local elections, etc.

The largest urban area in the United States is that of New York City, with its city proper population exceeding 8 million and its metropolitan area population almost 19 million. The next four largest urban areas in the U.S. are those of Los Angeles, Chicago, Miami and Philadelphia.^[10] About 70 percent of the population of the United States lives within the boundaries of urbanized area (210 out of 300 million). Combined, these areas occupy about 2 percent of the United States. The majority of urbanized area residents are suburbanites; core central city residents make up about 30 percent of the urbanized area population (about 60 out of 210 million).

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, villages, other built-up areas of more than 10 acres, 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 million acres in this category, an increase of 25 million acres since 1982. This article incorporates public domain material from the Congressional Research Service document "Report for Congress: Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition" by Jasper Womach.

See also

• ABCD Region: Industrial region made up of seven municipalities with the greater metropolitan area of São Paulo, Brazil
• Developed environments
  • Rural
  • Suburban
  • Exurban
  • Micro-urban
• Urban biosphere reserve
• Urban culture
• Urban decay
• Urban Terrain
• Urban warfare

Lists:

• Largest urban areas of Norway
• Largest urban areas of the European Union
• List of cities in Sweden by population
• List of cities in the People's Republic of China by urban population
• List of conurbations in the United Kingdom
• List of the 100 largest urban areas in Canada by population
• List of United States urban areas
• List of urban areas by population
• List of urban areas in Denmark by population
• List of urban areas in the Nordic countries
• Ranked list of New Zealand main urban areas

References

External links

• United Nations Statistics Division (UNSTAT): Definition of "urban"
• World Urban Areas All identified world urbanized areas 500,000+ and others: Population & Density. Author seeks advice on any that appear to be missing: wcox@demographia.com
• Geopolis: research group,university of Paris-Diderot, France for world urban areas
• Gridded Population of the World - contains links to urban area definitions and maps for over 230 countries/territories
• City Mayors - The World's Largest Urban Areas in 2006
• City Mayors - The World's Largest Urban Areas Projected for 2020