极端高温天气下公园热舒适影响因素分析——以福州市茶亭公园为例

Analysis of the Influencing Factors of Park Thermal Comfort under Extreme Hot Weather:Taking Chating Park in Fuzhou City as an Example

在极端高温天气频发的背景下,公园作为城市的重要“冷源”,对改善热环境问题尤为关键。以福州市茶亭公园6种典型空间单元为对象,通过多光谱、激光雷达、温湿度等数据,使用RayMan软件计算出生理等效温度(PET),揭示公园不同时段不同空间的热舒适特征,再结合皮尔森相关性分析、回归模型与熵权法,探讨不同时段不同空间热舒适度差异的驱动机制。结果表明:1)8:00—18:00,PET的变化呈先升后降的趋势,均值为39.1℃,在8:00—10:00时段达到最低,为33.7℃,人体感受为“稍热”,在14:00—16:00时段达到最高,为45.0℃,人体感受为“炎热”;2)不同空间类型平均热舒适度排序为:树荫全遮阴区>滨水全遮阴区>树荫半遮阴区>滨水开敞区>广场开敞区>硬质空地区;3)PET与天空开阔度(SVF)、硬质地面面积呈强正相关(0.924,0.909),PET与植被面积占比、归一化植被指数(NDVI)、三维绿量呈强负相关(-0.875,-0.878,-0.800);4)根据熵权法明确了各指标对热舒适度的影响程度排序为:三维绿量>SVF>植被面积占比>硬质地面面积占比>NDVI。研究结果揭示了公园时空上的热舒适变化情况,并厘清不同公园景观特征对改善热舒适环境能力的强弱,对福州市公园内部空间优化及提高人居环境热舒适具有重要的理论和实践意义。

In the context of increasingly frequent extreme high-temperature weather,parks serve as a vital"cooling source"within urban environments,making them essential for enhancing thermal conditions.This study focuses on six representative spatial units in Chating Park,Fuzhou City.By utilizing multispectral,LiDAR,and temperature and humidity data,the physiological equivalent temperature(PET)was calculated using RayMan software to assess the thermal comfort characteristics across various spatial units at different times.The study employed Pearson correlation analysis,regression modeling,and the entropy weighting method to investigate the driving mechanisms behind the variations in thermal comfort.The findings reveal that:1)Between 8:00 and 18:00,PET exhibited an initial increase followed by a decrease,with an average value of 39.1°C.The lowest PET of 33.7°C occurred from 8:00 to 10:00,which felt"slightly hot",while the highest value of 45.0°C was reached between 14:00 and 16:00,corresponding to a"hot"sensation;2)The average thermal comfort ranking among spatial types is as follows:fully shaded tree areas,fully shaded waterfront areas,semi-shaded tree areas,open waterfront areas,open plaza areas,and hard open spaces;3)PET showed strong positive correlations with sky view factor(SVF)and hard surface areas(0.924,0.909),and strong negative correlations with the proportion of vegetated area,normalized vegetation index(NDVI),and three-dimensional greenness(-0.875,-0.878,-0.800);4)The order of influence of various indices on thermal comfort,determined through the entropy weighting method,is:three-dimensional greenness>SVF>proportion of vegetated area>proportion of hard surface>NDVI.This study elucidates the spatial and temporal variations in thermal comfort within parks and delineates the effectiveness of different landscape features in enhancing thermal comfort.The findings have significant theoretical and practical implications for optimizing park spaces in Fuzhou City and improving thermal comfort in urban environments.