基于Landsat TM的地表热环境对城市扩展的响应——以重庆市南岸区为例

The Influence of Land Surface Thermal Environment on Urban Expansion Based on Landsat TM ——Taking Nanan District of Chongqing as an Example

重庆直辖以来,城市建设步入高速发展阶段,城市热岛效应已成为城市生态问题的热点。以重庆市南岸区为例,以1988、1993、2000、2007年和2010年5个时期的遥感和矢量数据为基础,在RS和GIS的支持下,通过对南岸区建设用地重心转移、地表温度变化、热岛中心转移进行动态研究,分析了研究区建设用地重心转移过程、地表温度空间分布差异以及热岛中心运动特点。结果表明:研究区在22年间,建设用地扩展明显,重心逐渐向东南方向转移,且转移速度逐年提高;地表温度空间分布格局变化明显,城市热岛现象日益显著;城市高温区下垫面多以建设用地为主,城市低温区下垫面多以水域和高植被覆盖为主;城市热岛中心空间变化与建设用地重心空间变化具有较高的一致性。研究成果可为城市规划与城市生态环境保护提供决策参考。

Since Chongqing became the municipality directly under central government,urban construction has been in rapid development period,and urban heat island effect has become a hot topic of urban ecological issues.Based on Landsat data and vector data of five stages in 1988,1993,2000,2007 and 2010,through dynamic study of barycenter transfer,surface temperature change and heat island center transfer of the construction land of Nanan District,this paper analyzes barycenter transfer process,land surface temperature space distribution difference and heat island center movement feature of the construction land in studied area,the research results show that,in the studied area in 22 years,construction land expansion is obvious,that its barycenter gradually transfers toward southeast direction and the transfer speed is increasing year after year,that land surface temperature space distribution pattern change is significant and urban heat island phenomenon is more and more remarkable,that the underlying surface in urban high temperature region mainly consists of construction land and the underlying surface of urban low temperature region is chiefly composed of waters and highly-populated plant coverage and that urban heat island center space change and construction land barycenter space change are highly consistent.This research result can provide policy reference for urban planning and ecological environment protection.