热带城市典型棕榈类与阔叶类乔木热舒适效应对比

Comparison of Thermal Comfort Effect Between Typical Palms and Broadleaved Trees in Tropical Cities

定量探究植物种类与体量对城市绿地热环境的影响机制,有助于应对气候变化对城市带来的负面影响,为改善城市绿地热舒适性提供策略依据。文章以海口市公共绿地为研究对象,选择棕榈类与阔叶类两种市内典型的乔木,结合样地实测与ENVI-met模拟,对比城市绿地中两种乔木的热舒适效应,探讨公共绿地在热舒适性方面的调节效应与植物选择策略。结果显示:植被遮荫不足、人工下垫面比例较高的绿地空间会出现热不适现象,所监测的公共绿地未能有效调节微气候、改善热舒适性;通过增加乔木植物绿量的模拟方案可调节微气候、改善场地热舒适性,使居民热感觉更接近舒适的状态;与低绿量的棕榈类乔木相比,高绿量的阔叶类乔木能更显著地改善公共绿地热舒适性,因此,提升当地生境适应性较强的阔叶类树种的种植比例是改善绿地环境热舒适性的有效策略。

The quantitative study of influence mechanism of plant species and volume on the thermal environment of urban green spaces can help address the negative impact of climate change on cities,and provide a strategy for improving the thermal comfort of urban green spaces.The paper takes Haikou public green space as the case and selects two tree species typical in the city,i.e.,palm and broadleaved trees,to compare their thermal comfort effect in the urban green spaces by combining the field measurement and ENVI-MET simulation,and to discuss the regulatory effect and plant selection strategy of public green spaces in terms of thermal comfort.The results show that the green space with insufficient shade and high proportion of artificial underlying surface would have thermal discomfort,and the public green spaces monitored are unable to effectively regulate the microclimate and improve the thermal comfort.The simulation scheme that increases the green amount of trees can adjust the microclimate,improve the thermal comfort,and make residents’thermal sensation closer to the comfortable state.Compared with palms that have a low green volume,broadleaved trees with high green volume can improve the thermal comfort of public green spaces more remarkably.Therefore,increasing the proportion of broadleaved trees with strong adaptability in local habitats is an effective strategy to improve the thermal comfort of green spaces.