Thermal comfort and green areas in Florence

Thermal comfort in urban environment is one of the major issue that future planning authorities will argue in the next years. It is well known that urban design at the micro-scale can influence human thermal comfort. In the last few years many authors have underlined the effect of the presence of green or high albedo materials on thermal comfort together with pedestrian heat stress. But it is not easy to translate the climate language into planning tools to be applied by urban planners. This study aims at quantifying the amount of hours, during the summer period, of thermal discomfort in the city of Florence in order to support planners to identify the needs of the city. Another purpose is to investigate the relationship between hours of thermal comfort and percentage of green area in the surroundings. Three biometeorological indices widely used to express thermal comfort in Italy (Steadman Apparent Temperature Index, Humidex, and Thom Discomfort Index) were calculated in 15 places in Florence urban area during Summer 2010. Results of this study quantify the difference in terms of thermal comfort that it is possible to find during the summer period in the city of Florence according to the biometeorological indices used, as well as the benefits in terms of thermal comfort of a 10% increase of green in an area of 250 m radius.