福州城市扩张对地表温度影响及其空间分异分析

Influence of Urban Expansion on Land Surface Temperature and Spatial Differentiation Analysis in Fuzhou,China

基于福州城区两时相Landsat影像,根据城市发展程度差异将研究区划分为Zone 1、Zone 2、Zone 3三个环形区域,在反演地表温度和获取不透水面覆盖度信息的基础上,计算各区域各级不透水面覆盖度的热分布指数和热效应贡献度指数,分析2004—2021年福州市不同发展程度区不透水面覆盖度与地表温度之间的定量关系,并运用地理探测器分析植被覆盖度、不透水面覆盖度和海拔高度对地表温度(Land Surface Temperature,LST)空间异质性的影响。结果表明:2004—2021年,Zone 1不透水面扩张较少,Zone 2和Zone 3不透水面扩张明显,增加最明显的为Zone 3内不透水面覆盖度大于60%的区域;不透水面覆盖度大于60%的区域对城市高温面积贡献最大,不透水面覆盖度为80%~100%时热效应贡献度最大;2004年影响地表温度的主导因子为植被覆盖度,2021年Zone 1中不透水面覆盖度为影响地表温度的主导因子,其余区域中海拔高度为影响地表温度的主导因子;福州市地表温度空间分异受多因子共同影响且两因子交互q值均高于单因子q值。研究结果可为城市规划和缓解城市热岛效应提供参考。

Based on the two-phase Landsat images of Fuzhou urban area,the study area was divided into three ring regions(Zone 1,Zone 2,Zone 3)according to the different development degrees of the cities.On the basis of Land Surface Temperature(LST)inversion and the obtained Impervious Surface Percentage(ISP)of the study area,the thermal distribution index and thermal effect contribution index of ISPs in different zones were calculated,and the quantitative relationship between ISP and LST in different development levels of Fuzhou from 2004 to 2021 was analyzed,and the influence of Fractional Vegetation Coverage(FVC),ISP and EL on spatial heterogeneity of LST was further analyzed by using geographic probe.The results show that:(1)From 2004 to 2021,the penetration of impervious water surface in Zone 1 is relatively low,while the penetration of impervious water surface in Zone 2 and Zone 3 is obvious.The most obvious increase is in Zone 3 with ISP greater than 60%.(2)The area with ISP greater than 60%contributes the most to the urban high temperature area and the area with ISP of 80%~100%contributes the most to the thermal effect.The contribution degree of thermal effect inthe study area is related to the ISP area at all levels in three regions with different development degrees.(3)From the perspectiveof single factor,the dominant factor affecting LST is FVC in 2004,ISP in Zone 1 in 2021,and EL in other ringzones.From the perspective of the interaction of two factors,the spatial differentiation of thermal environment in Fuzhou isthe result of multiple factors,and the q value of the interaction of two factors is higher than that of the single factor.The resultscan provide reference for urban planning and ecological environment construction.