Climate change and urban sustainability of Chilean metropolitan cities.

Abstract

Cities are at the same time cause and effect of climate change. Climate Change processes and effects should mainly affect Latin American cities, where most of the population and economic activities are concentrated. Urban climate changes are associated to urban heat island generation and development, and to hydrologic cycle alterations, particularly in terms of Area Total Imperviousness and Runoff Coefficients caused by watershed urbanization. City climate changes are a result of urban sprawl process that affect Chilean Metropolitan Areas (Valparaíso and Santiago). Land use/cover changes related with development of urban heat islands and micro-islands are analyzed in Santiago city on the basis of satellite images and measurement mobile transects. Changes in total imperviousness and runoff coefficients linked to urban sprawl are presented like main outcomes of Valparaiso expansion over hills and streams. Finally, spatial relationships between air temperatures, air pollution and socioeconomic population levels are used to demonstrate that urban climate changes have strong social components and that they are part of the socioenvironmental segregation that characterize Latin American cities.