基于Landsat TM的重庆都市区地表热环境时空变化研究

Research on Temporal and Spatial Changes of Land Thermal Environment Based on Landsat TM in Chongqing Metropolitan Area

随着城市化进程的加快、经济的高速发展,城市结构相应发生了一系列的改变,对城市的生态环境也产生了巨大的影响,城市热岛效应问题尤为突出。文章选取重庆都市区为研究对象,以Landsat-TM1988,2000和2011年三期夏季遥感影像为数据源,基于RS和GIS,采用单窗口算法对地表温度进行反演,并对城市地表温度的时空变化、热中心以及城市建设用地重心迁移进行分析,探讨城市地表热环境与城市扩张及下垫面的响应关系。研究结果表明:1988—2011年,研究区地表温度在空间上的分布存在明显差异性,区域温度整体有所上升,热环境问题日益严重;热中心与建设用地重心两者地迁移具有高度一致性;热环境效应强度与建设用地的分布情况大致呈正相关,与植被或水域的分布情况呈负相关。研究结果可为采取合理措施改善城市地表热环境效应、优化城市生态环境提供参考。

With the speedup of the urbanization and economic, a series changes of urban structure happened, which had a great influence on urban ecological environment, particularly on the heat island effect. Chongqing metropolitan area was taken as study area, the three periods of TM images from 1988 to 2011 in summer were chosen as the basic data sources. Based on GIS and RS, land surface temperature was inversed by the single-window method. The temporal and spatial changes of land surface temperature, translation of heat island center and urban center were analyzed systematically in this paper. The relationship between ur- ban thermal environment, urban expansion and city underlying surface were investigated. The results indi- cate that there are obvious distributions of land surface temperature from 1998 to 2011 and regional tempera- ture increased. The effects of thermal environment become serious. The heat center has highly consistency with migration of urban center. The intensity of thermal environment effects has positive correlation with distribution of construction, but has negative correlation with distribution of vegetation cover or water area. The results can provide references for improving effects of thermal environment and optimizing ecological en- vironment of urban area.