热岛效应季节动态随城市化进程演变的遥感监测

Monitoring the changes of urban heat island seasonal dynamics in the process of urbanization by remote sensing

作为城市特有的一种环境问题,热岛效应动态发展变化的规律是城市热岛研究的基础工作。遥感技术在城市热岛动态变化监测方面的有用性已经得到了证实。然而当前城市热岛遥感研究基本都取少数几景进行对比分析,这使得遥感在城市热岛时空动态监测方面不能充分发挥作用。采用50景长时间序列Landsat TM和ETM+SLC-on/off影像,采取定性和定量分析相结合的方法,使用热岛强度、热岛范围等指标和热岛显著区的概念对厦门市1987-2008年20年间热岛季节动态随城市化进程演变的趋势进行分析,结果表明:厦门城市热岛在2003、2004年之后已由春夏秋扩展到冬季,且冬季热岛的高等级斑块在数量、个体面积和总面积上均有明显增长趋势。引起这种变化的原因还需要进一步研究和分析。

As an environmental issue particular to cities,urban heat island bases its related research on monitoring the change dynamics of itself. Remote sensing has been proved to be very useful in this field. However,most of the remote sensing researches on urban heat island are based on the comparative analysis of quite few thermal images acquired on different dates,and could not make full use of remote sensing in monitoring the dynamics of urban heat island. This study uses a long time-series Landsat TM and ETM＋ SLC-on/off images with the number of 50 scenes,to analyze both qualitatively and quantitatively the changes of urban heat island seasonal dynamics in the past 20 years from 1987 to 2008,with indices such as UHI Intensity,Extent as well as UHI Area of Significance （UAS）. Results show that,the urban heat island of Xiamen has occurred remarkably in winter thus expanded to all the four seasons since the turning-point of the year 2003/2004. In addition,the high grade patches of winter urban heat island in Xiamen are increasing in not only their total number but also the individual area and total area. The causes of these changes are to be analyzed further in the future.