Climate change adaptation in cities: Enhancement of pedestrian thermal comfort using afforestation and greening buildings

Abstract

Climate change significantly impacts the outdoor urban environment, particularly streets, by intensifying the Urban Heat Island effect, leading to higher surface temperatures and reduced thermal comfort. Prolonged heat accelerates the deterioration of pavements and street furniture, increasing maintenance costs and compromising urban resilience. In addition to enhancing accessibility, streets play a significant role as spaces for social and economic activities. To support these functions, street designs must foster comfortable and engaging environments. With growing interest in sustainable urban design, the concept of outdoor thermal comfort is integral to street planning. This paper examines the impact of greening building facades and roofs, as well as increasing afforestation, on pedestrian thermal comfort using simulation during extreme weather conditions (hottest periods). A digital model of Ein Sarah Street in Hebron, West Bank, was created in Envi-met software, with each strategy applied separately to assess its effectiveness. A survey was conducted to validate the model, aligning simulated comfort levels with user experiences. Results indicate that afforestation reduce temperature by approximately 5.3 degrees, decrease Mean Radiant Temperature (MRT) by 1.4 degrees, and lower Physiological Equivalent Temperature (PET) by 0.9 degree. Increasing vegetation cover by 50 % reduces temperature by 5.3 degrees, MRT by 1.4 degrees, and PET by 0.9 degrees. This study uniquely integrates simulation with survey-based validation to evaluate the impact of greening strategies on outdoor thermal comfort in urban streets. By offering quantifiable insights into the cooling effects of green facades, green roofs, and enhanced vegetation in real-world contexts, it presents a practical approach to sustainable street design. This validation method enhances the model's reliability and applicability, providing urban planners with a valuable tool to improve pedestrian comfort and support climate change adaptation.