基于Landsat TM/TIRS的重庆市主城区热岛效应研究

Study of Urban Heat Island Based on Landsat TM/TIRS in the Central Area of Chongqing City

使用Landsat数据对2001—2013年重庆市主城热岛进行研究,选取2001年、2007年的TM、2013年的TIRS三期夏季影像,采用单窗算法反演出地表温度。在此基础上,对主城热岛时空演化的整体特征、热岛强度进行分析,得出以下结论:(1)重庆市高温地表主要分布在主城建成区内,由过去呈一点向多点、零散向成片的分布,发展至目前呈多片块、多中心均衡分布,并有持续向外扩展的趋势;(2)市区内绿化较好或有水体覆盖区域,对城市高温起到一定的缓解作用,而长江、嘉陵江表面温度与陆上地表温度相差较大;(3)13年间交通线路的发展带动了周围地区及周边区县的城市化发展,使得传统的高温区温度有所降低,在交通路线所能达到的地方形成新的高温区;(4)2001年热场变异指数为0.63,2007年为0.49,2013年达到0.66,较高的热场变异指数使得重庆市热岛强度处于较高水平。

Landsat data from 2001 to 2013were used to study Chongqing City urban heat island,and summer images of 2001,2007 and 2013 were selected to calculate the surface temperature via mono-window algorithm.On this basis,temporal and spatial variations of urban heat island in Chongqing City were analyzed.The results showed that：（1）high surface temperature areas of Chongqing distributed in urban area,from the past,it distributed from one to multi points,scattered to the plots,developed the present more balanced distribution of pieces,multi center,and had continued to expand outward trend;（2）those areas covered with green vegetation and water could alleviate high-temperature in downtown,and it differed quite largely between the Yangtze River,Jialing River and land surface in temperature;（3）development of transport routes led to the development of the nearby areas of the city and counties during the 13 years,decreased the traditional high-temperature areas,shaped new high-temperature areas where the traffic route can be reached;（4）the thermal field variability index was 0.63 in 2001,was 0.49 in 2007,and had reached 0.66 in 2013,ranking Chongqing high in China.The thermal field variability index changes differently in different areas during the study time.The urban heat island should be remained where it eased or be monitored where it enhanced or added.