Urban surfaces analysis with remote sensing data for the evaluation of UHI mitigation scenarios

Considering the new IPCC report and its recent suggestions, it is important to pay serious attention to the Urban Heat Island issue. In this study, satellite images acquired by the Worldview3 sensor (WV3) were processed to classify the different kinds of urban surface and to compute the albedo value for each surface. Then several UHI mitigation scenarios were analyzed, varying selectively the surface albedo by choosing solar reflective materials. Clay tile pitched roofs, dark roofs and parking areas were considered as “modifiable surfaces” and their albedo values were increased on the basis of the literature and of data made available by product manufacturers. For each proposed scenario, the reduction of intensity of the Urban Heat Island effect (ATD), the energy saving brought by lower absorption of air conditioning systems (ΔE) and the consequent cost savings were calculated. All the scenarios proved to be convenient and with a relatively fast return on investment. In particular, two scenarios involving the modification of several surfaces at the same time proved to be the most promising ones from the perspective of a public administration, with significant benefits on the well-being of the population, as well as with similar and relatively short payback periods.