非渗透表面对广州主城区地表热特征的影响

运用Landsat 5号和7号获得的遥感数据,评估广州地表热特征。为了量化城市土地利用程度和开发密度,对研究区基于子像元的非渗透表面丰度进行了分类。通过选择一定的非渗透表面丰度域值定义城乡边界和城市开发密度,应用陆地卫星热波段研究城市热格局。分析认为:可以基于量化的城市土地利用程度和开发密度确定地表热特征和格局。广州城区在日间具有热效应(热源),这种热效应与城市开发密度高度相关,即高丰度的非渗透表面通常与高地表温度相关联。基于植被冠层覆盖信息,证明城市非渗透表面丰度的时空分布及与其关联的热特征是量化城市土地利用、开发密度和城市热格局的有效资料。

Impacts of Impervious Surface on Urban Thermal Characteristics of Guangzhou

Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess urban area thermal characteristics in Guangzhou city of Zhujiang Delta.To quantitatively determine urban land use extents and development densities,sub-pixel impervious surface areas were mapped for this area.The urban-rural boundaries and urban development densities were defined by selecting certain imperviousness threshold values and Landsat thermal bands were used to investigate urban surface thermal patterns.Analysis results suggest that urban surface thermal characteristics and patterns can be identified qualitatively based on urban land use and development density data.Results show the urban area of Guangzhou has a daytime heating effect(heat-source).The thermal effects strongly correlated with urban development densities where higher percent imperviousness is usually associated with higher surface temperature.Using vegetation canopy coverage information,the spatial and temporal distributions of urban impervious surface and associated thermal characteristics are demonstrated to be very useful in quantifying urban land use,development intensity and urban thermal patterns.