The role of trees in enhancing outdoor thermal comfort during warm season in a sub-humid climate. Case: Souk Ahras city

Abstract

Enhancing the quality of life for people in urban areas necessitates focusing on outdoor thermal comfort OTC. This study examines the role and impact of urban vegetation, particularly trees, in improving the meteorological conditions that characterize the urban microclimate in order to enhance OTC, focusing on two public spaces in Souk Ahras city, characterised by in situ measurement campaigns and modelling during hot summer day. In situ campaigns were carried out to measure climatic data (air temperature, relative humidity and wind speed), and to collect data on vegetation (trees) and building geometry, which were used in numerical modelling to calculate the various thermal indices: SVF, Tmrt, PET and OUT_SET using the Rayman microclimatic model. The results show that the trees at each intervention site can reduce the average daily air temperature of 0.376?C to 1.04?C and an enhancement of thermal comfort in terms of average radiant temperature Tmrt of 2.08?C to 5.85?C and equivalent physiological temperature PET of 1.91?C to 3.84?C and standard equivalent temperature OUT_SET of 1.72?C to 2.86?C. in the knowledge that trees also help to reduce the Skye view factor, an essential geometric measure for assessing the thermal environment, which proves that the effect of shading and evapotranspiration provided by trees mainly contribute to enhancing outdoor thermal comfort during the warm season.