Study Roadmap Selection Based on the Thermal Comfort of Street Trees in Summer: A Case Study from a University Campus in China

Abstract

The intensification of the urban heat island effect, characterized by persistent high temperatures in Chinese cities during summer, has led to notable shifts in urban residents’ activity patterns and travel preferences. Given that street trees, as fundamental components of urban road networks, have significant interaction with residents, it is imperative to investigate their thermal comfort impact. This study aims to enhance the comfortable summer travel experience for urban dwellers. Fujian Agriculture and Forestry University (FAFU) was selected as the case study site, with eight street tree species identified as measurement points. The summer solstice (21 June 2023) served as the representative weather condition. Through monitoring temperature and humidity, the study explored the correlation between street tree species, their characteristic factors, and thermal comfort. Utilizing ENVI-met and ArcGIS, the thermal comfort of campus travel routes was assessed, leading to the development of a summer travel guide based on thermal comfort considerations. The research novelty lies in applying a combined ENVI-met 5.0.2 and ArcGIS 10.8 software approach for modelling and visualizing the microclimate, which enables a more precise analysis of the thermal comfort variations of different campus paths, thus improving the accuracy and applicability of the results in urban planning. The findings reveal several points. (1) Different street trees possess varying capacities to enhance human comfort, with Falcataria falcata and Mangifera indica exhibiting the strongest cooling and humidifying effects, whereas Bauhinia purpurea and Amygdalus persica perform the poorest. Additionally, the research confirms ENVI-met’s scientific accuracy and practicality for microclimate studies. (2) The contribution of street trees to the comfort of campus road travel is primarily determined by the Sky View Factor (SVF), which negatively correlates with cooling and humidifying intensity and positively with thermal comfort. (3) During midday, travel comfort conditions on campus roads are better. Based on the thermal comfort assessment, a summer roadmap was created for the campus. In this case, the campus roads indicated by road A are considered the best travel routes in summer, and the roads indicated by roads B and C are considered alternatives for travelling. This practical application demonstrates how theoretical research results can be translated into practical tools for daily commuting and urban planning. It provides data references and empirical cases for the scientific optimization and enhancement of urban roads.