局地气候区视角下城市空间形态的热环境效应——以泉州市为例

Effects of Urban Spatial Morphology on Thermal Environment from the Perspective of Local Climate Zone——A Case Study of Quanzhou City

局地气候区LCZ为局地尺度下揭示城市空间形态与热岛效应的关系提供了契机。然而以往研究缺乏多维因子对热岛效应的组合作用分析。本文基于泉州市的Landsat遥感数据、建筑普查数据,以空间形态特征为依据开展LCZ分类,比较不同LCZ的热环境分异特征,进而借助Pearson相关系数分析不同LCZ中空间形态因素与热岛强度UHII的相关关系,运用主成分多元回归方法探讨多种城市空间形态因素对UHII的综合影响与联动关系。结果表明:各LCZ的热环境特征具有显著差异,在建筑低矮、地表裸露的人工建成区(LCZ3、LCZ5等),热岛效应较为显著,而绿地(LCZ1)、水域(LCZ4)的热岛效应则较弱,两者的平均UHII分别为-1.788℃、-2.580℃。在各LCZ中,空间形态因素对UHII的影响程度差异明显,绿地比例、水域比例普遍与UHII呈负相关性,建筑密度、不透水面比例、建筑结构指数与UHII呈正相关性。建筑体积密度、建筑均匀指数、建筑平均高度、建筑高度差与UHII的相关性在各LCZ中并不一致,其相关性与LCZ本身的建筑密度、建筑高度有关。根据分析结果建议采取相应的城市空间规划策略,综合考虑规划策略的降温效率与实施的难易程度,以有效减缓热岛效应。

Local climate zones(LCZ)provides an opportunity to reveal the relationship between urban spatial morphology and the heat island effect at the local scale.However,previous literature rarely explores the combined effects of multidimensional factors on the urban heat island effect.Based on Landsat remote sensing data and building census data in Quanzhou,this study completed LCZ classification according to spatial morphological characteristics,and compared thermal environment differentiation characteristics of LCZs.Then,the correlation between spatial morphological factors and urban heat island intensity(UHII)in different LCZs was analyzed using Pearson correlation coefficient,and the combined effect and linkage relationship between the multidimensional spatial morphology factors and UHII was also explored using principal component multiple regression.The results show that the thermal environment characteristics are significantly different across LCZs.The built-up area(LCZ3,LCZ6,etc)has the more significant heat island effect,and the heat island effect of greenspace(LCZ1)and water(LCZ4)is weak,with an average UHII of-1.788℃and-2.580℃,respectively.In each LCZ,the influence level of spatial morphological factors on UHII is significantly different.For all LCZs,proportion of greenspace,and proportion of water show a negative correlation with UHII,while building density,building structure index and proportion of impervious surface show a positive correlation with UHII.The correlation between building volume density,building evenness index,building average height,the standard deviation of building height and UHII is not consistent across LCZs,which is related to the building density and building height in LCZs.According to the analysis results,it is suggested to adopt the corresponding urban spatial planning strategy,and consider the cooling efficiency and implementation difficulty of the planning strategy,so as to effectively alleviate the heat island effect.