Abstract

Urban areas present distinctive micro climates tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term “Urban Heat Island” describes this phenomenon. The urban heat island phenomenon has been the subject of intense study over the past several decades. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. These strategies generally fall into two categories; increasing urban albedo (reflectivity to solar radiation) and increasing gevapotranspiration. Albedo increases are generally accomplished through high albedo roofing and paving technologies. Increase in evapotranspiration is accomplished through a combination of decreasing the fraction of impervious surfaces and planting vegetation in urban areas (shade trees, vegetated walls, and rooftop gardens/ecoroofs). Related research into the effects of elevated urban temperatures on air quality, energy consumption, and human health has provided motivation for reducing the magnitude of the UHI (Urban Heat Island). To know the presence and to determine the intensity of UHI in the cities of Iran, a case study of Tehran is also carried out.