As urban areas across the globe have grown in size and density, significant changes have taken place in their landscapes. Buildings, roads, parking lots and other infrastructure have replaced open land and vegetation. Surfaces that were once permeable and moist have become impermeable and dry. As a result, urban regions have become much warmer than their rural surroundings, forming a “heat island” of higher temperatures.
Elevated temperatures in urban heat islands, especially during the summer, may have numerous negative consequences for the environment and quality of life in urban areas. These adverse consequences include increased peak energy consumption, higher risk of brownouts/blackouts, adverse health consequences, and impaired air and water quality.