基于ENVI-met绿化形式对夏季微气候及热舒适影响的研究：以桂林市为例

为研究夏季绿化形式对对滨湖步道微气候的影响，以桂林市两江四湖景区榕湖步道为例，结合现场测试和ENVI-met数值模拟方法，分析绿化形式对滨湖步道微气候的响应规律，并利用正交设计试验得出步道高宽比、植物排布形式和乔木冠层尺寸对微气候的贡献度关系，并提出最优绿化设计方案。结果表明：步道高宽比越大，降温效果越好，减湿效果越弱；两侧复合式绿化排布降温效果最优，两行开敞型绿化排布减湿效果最优；乔木冠层尺寸越小，降温效果越好；植物排布形式对湖泊中心的通用热气候指标UTCI（Universal Thermal Climate Index）变化的影响较大。通过非线性拟合和正交试验可知对空气温度和平均辐射温度贡献度关系为植物排布形式>步道高宽比>乔木冠层尺寸，且当步道高宽比为1.0，植物排布形式为两侧复合式绿化，乔木冠层尺寸为9 m时，滨湖步道微气候最优，符合人体热舒适标准，为城市绿化规划设计提供科学依据。

Effect of Greenery Form on Microclimate and Thermal Comfort in Summer Based on ENVI-met: A Case Study of Guilin, Guangxi

To study the effect of summer greening forms on the microclimate of the lakeshore walkway, the example of the Rong Lake walkway in the Two Rivers and Four Lakes scenic area of Guilin was used.Combining field tests and ENVI-met numerical simulations, the microclimate response of greening forms to the microclimate of the lakefront walkway was analyzed, and orthogonal design tests were used to derive the relationship between the height to width ratio of the walkway, plant arrangement forms and tree canopy size on the microclimate, and to propose the optimal greening design. The results showed that the larger the height to width ratio of the walkway, the better the cooling effect and the weaker the moisture reduction effect. The best cooling effect was obtained with the two-sided composite green walks, and the best moisture reduction effect was obtained with the two-row open green walks. The smaller the tree canopy size, the better the cooling effect. The effect of plant arrangement on the variation of the Universal Thermal Climate Index (UTCI) in the center of the lake was significant. The non-linear fitting and the orthogonal test showed that the contribution to the air temperature and the mean radiation temperature is as follows: plant arrangement > walkway height to width ratio > tree canopy size. When the walkway height to walkway height to width ratio of 1.0, two-sided composite green walks and tree canopy size of 9 m, the microclimate of the lakeside walkway was optimal and conformed to human thermal comfort standards, providing a scientific basis for urban greening planning and design.