Urban area

An urban area, or urban agglomeration, is a human settlement with 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 and 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 leads to human impact on the environment. An urban area, or urban agglomeration, is a human settlement with 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 and 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 leads to human impact on the environment. 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. Urban areas are created and further developed by the process of urbanization. Urban areas are measured for various purposes, including analyzing population density and urban sprawl. 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. European countries 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, 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. 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. The population is unequally distributed amongst the provinces: about 60% live in the Pampa region (21% of the total area), including 20 million people in Buenos Aires Province; Córdoba Province Santa Fe Province and the Autonomous City of Buenos Aires have 3 million each. Seven other provinces have over one million people each: Mendoza, Tucumán, Entre Ríos, Salta, Chaco, Corrientes and Misiones. Tucumán is the most densely populated with 60 per square kilometre (160/sq mi), the only Argentine province more densely populated than the world average, while the southern province of Santa Cruz has around 1 inhabitant per square kilometre (2.6/sq mi). 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 the Australia's three biggest urban centres.