Examine individual changes

''''Urban density''' is a term used in [[urban planning]] and [[urban design]] to refer to the number of people inhabiting a given [[urbanized area]]. As such it is to be distinguished from other measures of [[population density]]. Urban density is considered an important factor in understanding how cities function. Research related to urban density occurs across diverse areas, including economics, health, innovation, psychology and geography as well as [[sustainability]]. == Sustainability == [[File:Revised_petrol_use_urban_density.JPG|thumb|A graph showing the relationship between urban density and petrol use.]] It is commonly asserted that higher density cities are more sustainable than low density cities. Much urban [[Urban planning|planning theory]], particularly in North America, the UK, Australia and New Zealand has been developed premised on raising urban densities, such as [[New Urbanism]], [[Transit-oriented development]], and [[Smart growth]]. {{Citation needed|date=November 2014}} However, the link between urban density and aspects of [[sustainability]] remains a contested area of planning theory{{Citation needed|date=November 2014}}.<ref>{{Cite journal|url = http://pubs.acs.org/doi/abs/10.1021/es4034364|title = Spatial Distribution of U.S. Household Carbon Footprints Reveals Suburbanization Undermines Greenhouse Gas Benefits of Urban Population Density|last = Jones|first = Christopher|date = Energy and Resources Group, ‡Goldman School of Public Policy, and §Department of Nuclear Engineering, University of California, Berkeley, California 94720, United States Environ. Sci. Technol., 2014, 48 (2), pp 895–902|journal poop = Environmental Science and Technology|accessdate = December 13, 2013|doi = 10.1021/es4034364|pmid = }}</ref> [[Jan Gehl]], prominent Urban Designer and expert on [[sustainable urbanism]], argues that low-density, dispersed cities are unsustainable as they are [[Automobile dependency|automobile dependent]]. A minority, such as Randy O'Toole of the Libertarian [[Cato Institute]], counter that raising densities results in more expensive real estate, greater road congestion and more localized air pollution. Others counter that traffic congestion is a result not of population density but of parking capacity.<ref>{{cite web |title=More density does not equal more [car] traffic |author=Jacobsen, Shaun |date={{date|2014-01-14|iso}} |quote=...tall buildings don’t create traffic. Cars create traffic. If we want less [automobile] traffic on the streets, we need to build less capacity for them, including parking. |url=http://transitized.com/2014/01/14/density-equal-car-traffic/ |publisher=Transitized}}</ref> At a broader level, there is evidence to indicate a strong negative correlation between the total energy consumption of a city and its overall urban density, i.e. the lower the density, the more energy consumed.<ref> {{cite book |last= Newman |first= Peter |author2=Jeffrey R. Kenworthy |title= Sustainability and Cities: Overcoming Automobile Dependence |year= 1999 |publisher= Island Press |isbn= 1-55963-660-2 }}</ref> == Measurement == '''Urban density''' is a very specific measurement of the population of an urbanized area, excluding non-urban land-uses. Non-urban uses include regional open space, agriculture and water-bodies. There are a variety of other ways of measuring the density of urban areas: * [[Floor area ratio]] - the total floor area of buildings divided by land area of the lot upon which the buildings are built * Residential density - the number of dwelling units in any given area * [[Population density]] - the number of human persons in any given area * employment density - the number of jobs in any given area * Gross density - any density figure for a given area of land that includes uses not necessarily directly relevant to the figure (usually roads and other transport infrastructure) * Net density - a density figure for a given area of land that excludes land not directly related to the figure. * Weighted density - a density metric which measures the density at which the average citizen lives. It is determined by calculating the standard density of each census tract, assigning each a weight equal to its share of the total population, and then adding the segments. == See also == * [[List of cities proper by population density]] * [[Transportation planning]] * [[Urban sprawl]] * [[Verticalization]] == References == {{reflist}} == Further reading == * [[Peter Newman (Australian)|Newman, P]] and Kenworthy, J (1999) Cities and Sustainability: Overcoming automobile dependence, Washington, D. C. : Island Press ISBN 1-55963-660-2 * Pont, Meta Y. Berghauser and Haupt, Per (2010) ''Spacematrix: Space, Density and Urban Form'', NAi Publishers, ISBN 9789056627423 * [[Kim Dovey|Dovey, Kim]] and Pafka, Elek (2014) "The urban density assemblage: Modelling multiple measures" in ''Urban Design International'', vol.19, nr. 1, pg.66-76 == External links == * [http://densityatlas.org/ MIT Density Atlas] * [http://people.hofstra.edu/geotrans/eng/ch8en/conc8en/urbanenergy.html Urban Density and Energy Consumption] {{DEFAULTSORT:Urban density}} [[Category:Urban planning]] [[Category:Sustainable development]] [[Category:Demography]] [[Category:Population]]'