Urban area

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

The world's urban population in 1950 of just 746 million has soared 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 7.25 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.

Urban area (France)

An aire urbaine (literal and official translation: "urban area") is an INSEE (France's national statistics bureau) statistical concept describing a core of urban development and the extent of its commuter activity. When applied to larger agglomerations, this unit becomes similar to a U.S. metropolitan area, and the INSEE sometimes uses the term aire métropolitaine to refer to France's larger aires urbaines.

Composition

The aire urbaine is based on France's nationwide map of interlocking administrative commune municipalities: when a commune has over 2000 inhabitants and contains a centre of dense construction (buildings spaced no more than 200 metres apart), it is combined with other adjoining communes fulfilling the same criteria to become a single unité urbaine ("urban unit" ); if an urban unit offers over 10,000 jobs and its economical development is enough to draw more than 40% of the population of a nearby municipalities (and other municipalities drawn to these in the same way) as commuters, it becomes a pôle urbain ("urban cluster") and the "commuter municipalities" become its couronne ("rim"), but this only on the condition that the urban unit itself is not part of another urban cluster's rim. The aire urbaine is an urban cluster and its rim combined, or a statistical area describing a central urban core and its economic influence on surrounding municipalities.

United States urban area

Urban areas in the United States are defined by the U.S. Census Bureau as contiguous census block groups with a population density of at least 1,000/sq mi (390/km²) with any census block groups around this core having a density of at least 500/sq mi (190/km²). Urban areas are delineated without regard to political boundaries. The census has two distinct categories of urban areas. Urbanized Areas have populations of greater than 50,000, while Urban Clusters have populations of less than 50,000 but more than 2,500. An urbanized area may serve as the core of a metropolitan statistical area, while an urban cluster may be the core of a micropolitan statistical area.

See also