呼和浩特城市冷热岛的景观特征分析

Analysis of the Landscape Characteristics of the Cold and Heat Island in Hohhot

基于Landsat 8 TIRS、2017年清华10 m土地利用数据集,以呼和浩特市中心城区为研究对象,运用大气校正和均值-标准差法对呼市城区地表温度(LST)进行反演,并提取冷热岛边界。对比分析不同土地利用类型对冷热岛的影响,找出对呼和浩特市城区地表温度影响最大的地物;利用空间梯度分析法定量阐述不透水面和植被覆盖度与LST的关系,并分析研究区LST的空间分布特性。结果表明,植被在冷岛范围内对LST变化影响最大,而不透水面在热岛内对其作用最大;LST平均值随距离研究区几何中心的辐射距增大而逐渐降低,与不透水面密度走向基本一致,与植被覆盖度走向呈相反趋势,且植被对LST的降温效率小于不透水面对其的增温效率。

Based on the Landsat 8 TIRS,and the 2017 Tsinghua 10 m land use data set,the central urban area of Hohhot was taken as the research object,the atmospheric correction and mean-standard deviation methods were used to invert the surface temperature(LST)of the urban area of Hohhot,and extract the boundary of the cold and heat island.Through the comparative analysis of the effects of different land use types on the cold and heat island,the surface features which had the greatest impact on the surface temperature of the urban area of Hohhot were found.The spatial gradient analysis methods were used to quantitatively explain the relationships between the impervious surface,vegetation coverage,and LST.The spatial distribution characteristics of the LST were analyzed as well.The results showed that the vegetation had the greatest influences on the LST change in the cold island,while the impervious surface had the greatest effects on the LST change in the heat island.The mean LST value decreased with the increase of the radiation distance from the geometric center of the study area,which was basically consistent with the density trend of the impervious surface,but the trend of the vegetation coverage was opposite,and the cooling efficiency of the vegetation to the LST was less than that of the impervious surface.