基于MODIS的大气因素对蓝藻水华信息提取的影响(英文)  

Effects of Atmospheric Factor on the Retrieval of Cyanobacteria Bloom with MODIS Images

作　　者：张月[1] 刘元波[2] 夏双[3] 阮仁宗[3] 

机构地区：[1]吉林农业大学资源与环境学院,长春130018 [2]中国科学院南京地理与湖泊研究所,南京210008 [3]河海大学地球科学与工程学院,南京210098

出　　处：《遥感信息》2013年第5期37-44,51,共9页Remote Sensing Information

基　　金：江苏省自然科学基金(BK2008360);中央高校基本科研业务费专项资金项目(2009B12714,2009B11714)

摘　　要：本文利用MODIS提供的两种影像产品和代表大气条件的气溶胶产品,运用单波段(NIR)和比值植被指数(NIR/G)两种方法分别提取太湖蓝藻信息。在阐述气溶胶的光学厚度对遥感影像影响的基础上,定量分析了气溶胶光学厚度对两种方法提取蓝藻水华面积的净变化值和选取阈值的影响程度。研究结果表明,运用单波段和比值植被指数两种方法提取太湖蓝藻水华面积差异与气溶胶光学厚度的相关性,固定阈值情况下的相关性高于自选阈值中的对应值。两种指数中大气校正前的阈值与气溶胶光学厚度的相关性都要高于大气校正后两者的相关性。这说明大气会对阈值的设定产生一定的影响,进而影响蓝藻信息提取精度。因此,定量分析气溶胶光学厚度对监测蓝藻是至关重要的。In recent years,frequent cyanobacteria bloom in Lake Taihu has caught a lot of attention from the communities of environment and water resources;and also the organizations relative to human and animal health.Remote sensing technology can be used to monitor the trends of cyanobacteria bloom extensively.However,the changing atmospheric conditions and other factors will have a significant effect on the extraction of cyanobacteria bloom information.In this paper,three kinds of MODIS products were selected for the analysis of the effects of one important factor of atmosphere,aerosol optical thickness,on monitoring cyanobacteria bloom.The extraction of cyanobacteria bloom in Lake Taihu was carried out by using the single band method and ratio vegetation index method,respectively.Then,the quantitative relationships between effects of aerosol optical thickness and each of the net difference of the area of cyanobacteria bloom and threshold selection were explored.The correlation coefficients between aerosol optical thickness and the net difference of the area of cyanobacteria bloom are 0.46and0.34with the fixed threshold while the correlation coefficients between aerosol optical thickness and the net difference of the area of cyanobacteria bloom are 0.02and 0.16 with the adjustable threshold method.The correlation coefficients between aerosol optical thickness and the threshold with MOD02and MOD09images are 0.56and 0.40by using the single band method while they are 0.27and 0.04by using the ratio vegetation index.For both single band method and ratio vegetation index method,the correlation between aerosol optical thickness and the threshold before atmospheric correction is greater than that after atmospheric correction.It indicates that the atmosphere certainly has an impact on the threshold settings,thus affecting the extraction accuracy of cyanobacteria bloom.Therefore,the quantitative analysis of the effects of aerosol optical thickness is significant for accurately monitoring cyanobacteria.

关 键 词：太湖 MODIS 蓝藻水华 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]