Mapping urbanization in the United States from 2001 to 2011

We combine Landsat and MODIS data with the CIESIN population products to generate observation-based maps characterizing past (2001) and near-present (2011) land use change in the continental United States (CONUS) with emphasis on urban development characterized by impervious surface area (ISA). At city-scale urbanization appears to implicitly include a ‘cultural character’ whereby depending on the region, cities are either built horizontally using large ISA per capita or becoming denser and possibly using vertical structures with small spatial footprints. This ‘cultural character’ is modulated by land availability, topography, coastlines proximity and land use policy regulation. Regionally, the largest population and ISA change between 2001 and 2011 occurred in the South, while the most noticeable ISA per capita increases are observed in urban centers of the South and Midwest. The South has the highest population and population change, the greatest ISA extent and ISA change, while the Midwest is characterized by the highest per capita ISA use. All regions show an increase in ISA per capita during the decade except for the West which showed a decline. Overall, by 2011 urbanization has sprawled 11% relative to 2001, and ISA per capita use decreases as cities’ size increases.