Optimization strategies for outdoor thermal comfort at urban core transportation hub in summer--A case of Turpan Station, China

• The first OTC study of urban core transportation hubs in dry and hot areas in China. • Tmrt is the most important factor affecting the UTCI index. • Integrating blue-green infrastructure, the mean Tmrt and UTCI decreased by 5.12 °C and 1.73 °C. • The duration of "extreme heat stress" has been reduced by 2 hours compared to the initial state . • Improvement strategies are based on the characteristics of different functional zones. As global warming escalates, high-intensity heat waves are increasingly common, raising concerns about their impact on environmental systems and public health. This article focuses on Turpan City, known for having the highest summer temperatures in China, emphasizing its largest transportation hub, Turpan North Station. The study employs field research and data measurement to analyze the local summer climate conditions. Additionally, simulation methods were utilized to assess the spatial and temporal changes in the area’s thermal environment. The research also evaluates six design scenes featuring various configurations of blue-green infrastructure, using the Universal Thermal Climate Index (UTCI) for evaluation. The results show that the average radiation temperature (Tmrt) becomes the primary factor influencing the UTCI. The incorporation of tall trees in varying proportions leads to a substantial reduction in Tmrt, with the greatest decrease amounting to 6.79°C. Furthermore, through the strategic allocation of urban blue-green infrastructure, the UTCI values are decreased by 1.33°C relative to the actual situation and by 1.73°C when compared to simulations lacking blue-green infrastructure. Moreover, the duration of "extreme heat stress" is reduced by a duration of 2 hours. This study also suggests targeted optimization and improvement strategies based on the characteristics of various functional zones surrounding transportation stations. Overall, it provides a robust theoretical foundation and practical guidance for the scientific planning and effective arrangement of the outdoor thermal environment in rail transit buildings in dry and hot regions.