Empirical Evaluation of Urban Heat Island Pavements Related. Cagliari Case Study

Worldwide, higher temperatures occur in urban areas (UHI - Urban Heat Island) compared to the surrounding countryside, with a considerable impact on people’s health and well-being. Extensive use of paved surface and bituminous materials and human activity heat generation are the major causes of the UHI. The paper points out the importance of bituminous pavements on UHI and reports the empirical evaluation performed in Cagliari (Italy). Using thermal data from the Italian SmartRunway located in Cagliari airport, a fitting empirical model developed for bituminous pavement surface (R2 < 0.94) has been extended to other materials used in the urban context. The model input data are a minimum and maximum air temperature and solar irradiation during the day, and output is the surface temperature. The simplified characterization of different kinds of surfaces covering the cities can be operated through visual analysis of orthophotos or a geodatabase. Combining these data, in the paper is proposed a methodology to build temperature profile along a town cross-section. Finally, a zenithally thermal survey has validated the empirical methodology, with a significant correlation (R2 > 81%).