城市扩张下的哈尔滨地表温度空间变化态势分析

为探究地表温度时空变化特征对城市热岛效应、生态环境质量的影响,以哈尔滨市为例,将以2001、2008、2013和2016年4期Landsat卫星遥感影像为基础数据,采用辐射传输法、密度分割、象限方位法、缓冲区分析以及回归分析等方法,对哈尔滨市地表温度进行反演并划分等级,分析哈尔滨市地表温度时空分异总体特征,同时定量揭示并阐述地表温度和归一化建筑指数NDBI的相关性。结果表明:高温区主要集中在相应时期的建成区及工业园区,而水体、绿地及耕地则表现出明显的低温区;2001—2016年哈尔滨市高温区域扩张明显,但是在不同时期表现出不同的扩张方向、范围和模式;高温区域与城市建设用地空间分布具有一致性,城市化进程和人口流动加快高温区范围的扩张;地表温度和NDBI呈显著正相关,NDBI在表征热环境特征方面具有一定代表性。

Analysis of spatial variation of land surface temperature in Harbin under the urban area expansion

Research on the spatial and temporal variation of surface temperature is crucial to establish appropriate urban heat island mitigation strategies and improve the environmental quality. The radiative transfer algorithm was used to retrieve land surface temperature (LST) in Harbin City in summer of 2001, 2008, 2013 and 2016. Density segmentation, orientation quadrant, buffer analysis and regression analysis method were adopted to perform inversion and classification of land surface temperature, analyze the land surface temperature space change characteristics, reveal and expound the correlation between land surface temperature and the normalize construction index NDBI. The results showed that:From 2001 to 2016, significant high temperature regions were mainly in the Harbin urbanized area and industrial area, and significant low temperature were mainly in water bodies, green land and arable land; High temperature regions continuously increased during 2001 to 2016, while the expanding trend, extent and model differed from each other; The spatial distribution of the high temperature area and the urban construction land was consistent. The process of urbanization and population movements accelerated the expansion of the range of the high temperature area. A significant positive correlation between surface temperature and NDBI was discovered, which meant that NDBI was good indicator for marking surface thermal characteristics.