PET classes frequencies

Analysis of thermal bioclimate in various urban configurations in Athens, Greece


Studies on human thermal comfort in urban areas typically quantify and assess the influence of the atmospheric parameters studying the values and their patterns of the selected index or parameter. In this paper, the interpretation tools are the first derivative of the selected parameters (∆Parameter/∆t) and the violin plots. Using these tools, the effect of sites’ configuration on thermal conditions was investigated. Both derivatives and violin plots indicated the ability of vegetation to act as a buffer to the rapid changes of air temperature, mean radiant temperature, and the physiologically equivalent temperature (PET). The study is focused on the “thermal extreme” seasons of winter (December, January, and February) and summer (June, July, and August) during a 3-year period of measurements in five selected sites under calm wind and sunny conditions. According to the results, the absence of vegetation leads to high derivative values whereas the existence of dense vegetation tends to keep the parameters’ values relatively low, especially under hot weather conditions.

Urban Ecosystems