A field research on the impact of underlying surface configuration on street thermal environment in Lhasa

摘要

Commercial street is an important place for outdoor activities of urban residents. The quality of its thermal environment directly affects the comfort of pedestrians and the energy consumption of surrounding buildings. Block-scale microclimate studies have already been conducted in the context of different climates, while limited attention has been paid to the microclimate within high-altitude cold climate. Tibet, as the main body of the Qinghai-Tibet Plateau, presents typical plateau climate characteristics, and its unique natural climate conditions will certainly give birth to special urban environmental problems. Therefore, taking Lhasa as an example, this paper focuses on the impact of street thermal environment under different underlying surface configurations under unique plateau climate conditions. Based on the field measurement of the thermal environment of three streets in Lhasa City, namely, Yutuo Road, Duosen Road and Hongqi Road, the influence of different underlying surface design elements, namely, greening and water area, on the near ground microclimate and pedestrian comfort of the streets were analyzed. The analysis results of the measured datas show that: there are obvious temperature differences in the streets of different directions. Trees have a more significant cooling effect on East-West streets. The leaf area index (LAI) of trees will affect the improvement of thermal environment. Fountain has cooling effect in summer, but it is lower than that of trees. The research contents of this paper provides data basis for further research on the thermal environment and the optimization design of the underlying surface of the streets in the high altitude cold climate area.