Three years of study of the Urban Heat Island in Padua: Experimental results

The Urban Heat Island effect concerns the higher air temperature in urban environment with respect to the rural one. This phenomenon has been well known for hundreds of years, but it has been experimentally studied only for the last few decades and in large metropolis. The paper reports on the experimental results obtained during the period 2010–2011 in a medium size city of Italy by the research group of the Department of Environmental Agronomy and Crop Productions of the University of Padua. During the summer of 2012 the work has been developed by the authors, in cooperation with Co.Ri.La. (Venice) within the European Project “UHI – Development and application of mitigation and adaptation strategies and measures for counteracting the global Urban Heat Islands phenomenon” (3CE292P3). The main thermohygrometric variables (air temperature, relative humidity, global solar radiation) have been measured along some different paths fixed in advance, crossing different zones of the city area: urban, sub-urban and rural. The high number of mobile surveys implemented in different time bands during the day and after the sunset allows to characterize the phenomenon. The results indicate a presence of the UHI in urban zones of the city up to 6 °C. Some measurements in situ have been further conducted in order to evaluate the mean radiant temperature as well as in some characteristic sites of the city area: historic center, high and low density populated residential zones, industrial zone, rural zone.