城市绿地景观格局影响地表温度的通径分析——以长沙市为例  

Path Analysis of the Urban Greenspace Landscape Pattern Impacts on Land Surface Temperature:A Case Study in Changsha

作　　者：蒋恬田 杨纯[1] 廖炜 胡力 刘欢瑶[3] 任勃[3] 李小马 JIANG Tiantian;YANG Chun;LIAO Wei;HU Li;LIU Huanyao;REN Bo;LI Xiaoma(Hunan Provincial Key Laboratory of Landscape Ecology and Planning&Design in Regular Higher Educational Institutions/College of Landscape Architecture and Art Design,Hunan Agricultural University,Changsha 410128,P.R.China;College of Engineering Management,Hunan University of Finace and Economics,Changsha 410205,P.R.China;Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area/College of Resources&Environment,Hunan Agricultural University,Changsha 410128,P.R.China)

机构地区：[1]园林生态与规划设计湖南省普通高等学校重点实验室/湖南农业大学风景园林与艺术设计学院,湖南长沙410128 [2]湖南财政经济学院工程管理学院,湖南长沙410205 [3]洞庭湖区农村生态系统健康湖南省重点实验室/湖南农业大学资源与环境学院,湖南长沙410128

出　　处：《生态环境学报》2023年第1期18-25,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金青年项目(32001161);湖南省自然科学基金面上项目(2021JJ30329)。

摘　　要：优化绿地景观格局是城市绿化土地有限背景下改善城市热环境的有效途径,阐明绿地景观格局影响城市热环境的路径与机制是合理并有效地规划与管理城市绿地的基础。以长沙市为例,利用高分2号高分辨率遥感影像在乡镇(街道)尺度量化绿地面积比例和景观配置格局,基于Landsat地表温度采用通径分析方法揭示绿地景观格局影响地表温度的路径,分析其直接效应和间接效应。结果显示:(1)绿地面积比例、水体面积比例、裸地面积比例和绿地斑块密度对地表温度呈显著的直接负效应,共解释85%的地表温度变异,直接路径系数分别为-0.61、-0.54、-0.29和-0.21;(2)绿地面积比例对绿地斑块密度呈显著的直接负效应(直接路径系数-0.46),而绿地斑块密度对地表温度呈显著的直接负效应(直接路径系数-0.21),因此绿地面积比例增加间接导致地表温度升高(间接路径系数0.10),从而削弱提高绿化覆盖率以改善城市热环境的效果;(3)绿地边界密度受绿地面积比例、绿地平均斑块形状指数和绿地斑块密度显著影响,但其对地表温度的影响不显著。因此,以小面积斑块为主的见缝插绿式绿地建设是长沙城市绿地规划管理以改善城市热环境的有效措施。Optimizing the landscape pattern of urban greenspace has been widely acknowledged as an effective strategy to improve the urban thermal environment(UTE),especially when land is very limited for greening in urban areas.The landscape pattern of urban greenspace includes two aspects:landscape component(i.e.,percent green cover)and landscape configuration(e.g.,patch density,edge density,and patch shape).The significant negative relationships between percent green cover and urban thermal environment usually measured by air temperature(AT)and land surface temperature(LST)are consistently reported in the literature,but the relationships between landscape configuration of urban greenspace and UTE varied among studies in terms of significance,direction,and magnitude.There are strong correlations between percent green cover and landscape configuration of urban greenspace,which may impact the observed impacts of landscape pattern of urban greenspace on UTE.For example,the increase in percent green cover may decrease the patch density of urban greenspace.Therefore,the percent green cover may,directly and indirectly,impact AT or LST.Uncovering the paths of the impact of urban greenspace landscape patterns on UTE can help better understand the mechanism of the impact of urban greenspace landscape patterns on UTE and design more cost-effective urban planning and management policies.Taking Changsha as a case study,we measured the landscape pattern of urban greenspace by the commonly used landscape metrics(i.e.,percent green cover,percent water cover,percent bare land cover,patch density of greenspace,edge density of greenspace,and mean patch shape index of greenspace)for 69 census tracts(administrative units at the town level)based on the proportion of green coverage and landscape configuration pattern at the township scale from the Gaofen-2 satellite high-resolution remote sensing images taken on 3rd November 2019.Mean LST for each census tract was quantified based on the LST data obtained from Landsat-8 on a clear sky day on17

关 键 词：城市热环境 地表温度 景观配置 城市绿地 通径分析 

分 类 号：Q948[生物学—植物学] X16[环境科学与工程—环境科学]