北京市热岛效应时空变化的HJ-1B监测分析

 本文利用2008-2011年HJ-1B/CCD可见光-近红外数据,以及HJ-1B/IRS热红外数据,采用遥感算法反演北京市地表温度,并用MODIS地表温度产品对反演结果进行了初步验证。同时分析了北京市热岛效应的年际、年内变化趋势。另利用热场变异指数分析其空间分布特征,以及NDVI、NDBI与城市下垫面对热岛效应的影响。结果表明:(1)2008-2010年北京市热岛强度总体呈上升趋势,2011年有所缓解,4年热岛强度分别为:5.2℃、5.2℃、9.2℃、8.2℃;(2)北京市2010年四季存在明显热岛现象,夏季最强,春、秋次之,冬季最弱,四季热岛强度分别为8.2℃、9.4℃、9.2℃、4.3℃;(3)2008-2011年北京市热岛空间分布特征表明,房山区和大兴区的南部热岛效应逐年缓解,2011年昌平区热岛效应比前3年明显,植被和水体形成城市冷岛;(4)地表温度与NDVI呈明显负相关,与NDBI呈正相关,城市热岛效应与下垫面类型存在明显相关性。

Monitoring Spatio-Temporal Changes of Heat Island Effect in Beijing Based on HJ-1B

The change of land surface temperature（LST）can reveal the heat environment of city,which leads to urban heat island（UHI）.As a metropolis,Beijing has a serious urban heat island effect,so,analyzing and studying spatial and temporal changes of Beijing＇s urban heat island has a great significance.In this paper,we referenced image-based method to retrieve the land surface temperature using Environment Satellite image（HJ-1B） CCD/IRS as the main data source from 2008 to 2011,made preliminary validation on retrieval result using MODIS temperature products,then analyzed the annual and inter annual changes of urban heat island effect in Beijing.Further,we used thermal field variability index to make quantitative analyze of UHI.Finally,we analyzed the relationship among NDVI,NDBI and land use types.The results show that：（1） between 2008 and 2011,there is a significant heat island effect in Beijing.The heat island expanded from 2008 to 2010 but eased in 2011,the UHI were 5.2℃,5.2℃,9.2℃ and 8.2℃,respectively;（2） There is a significant heat island effect in four seasons of Beijing in 2010,the heat island in summer is the strongest,followed by spring and autumn,winter is the weakest,and the UHI were 8.2℃,9.4℃,9.2℃ and 4.3℃,respectively;（3） The quantitative distribution of UHI in Beijing from 2008 to 2011 showed that the UHI is mainly in urban,the heat island effect in the Southern of Fangshan District and Daxing District reduced year by year,the heat island effect of Changping District in 2011 is higher than in the previous three years,and vegetation and water formed urban cool island;（4） LST and NDVI are negatively correlated.LST and NDBI are positively correlated obviously,NDVI and NDBI have a significant impact on urban heat island,and urban heat island has a clear correction with land use types.So,increasing the city green area and water area can effectively slow down the heat island effect.