Remotely sensing the cooling effects of city scale efforts to reduce urban heat island

Chicago has implemented a variety of strategies to combat the urban heat island effect including increasing vegetation (e.g., tree planting, green roofs) and raising the albedo of built surfaces (e.g., painting roofs light colors). This study used LandSat images and aerial imagery from before implementation (pre-1995) and closer to the time of the study (2007-2010) to measure changes in temperature, albedo, and the normalized difference vegetation index (NVDI) to determine the impacts of this large-scale effort to reduce urban heat islands. Both increased vegetation and increased albedo had strongly inverse relationships to temperature, indicating that both were effective in reducing temperature. Increased albedo, however, was shown to produce greater cooling effects and therefore possibly to be a more successful strategy for similar cities.