利用Landsat卫星影像研究浙闽地区表层悬浮体的分布和迁移

DISTRIBUTION AND MIGRATION PATTERN OF SURFICIAL SUSPENDED MATTER IN ZHEJIANG AND FUJIAN MUD AREA DETECTED BY LANDSAT SATELLITE IMAGES

基于2007年2月和2015年6月的东海悬浮体浓度数据,分别对2007年2月、7月的Landsat Thematic Mapper(Landsat-TM)和2014年12月、2015年6月Landsat Operational Land Imager(Landsat-OLI)卫星影像建立表层悬浮体浓度反演模型,发现建立的指数函数模型反演效果最佳,相关系数分别为0.971和0.856,其可以反映冬夏两季表层悬浮体分布特征及其控制作用。研究发现,浙闽沿岸海域表层悬浮体浓度呈近岸高远岸低、冬季高夏季低的特点;冬季浙闽沿岸流携带的表层悬浮体浓度范围为10~28mg/L,台湾暖流为1.5~5mg/L;夏季浙闽沿岸流携带的表层悬浮体浓度范围为4~22mg/L,台湾暖流为1.2~2.3mg/L。并且在冬季发现在40m水深海域存在较明显的表层悬浮体浓度次级锋面及一系列涡旋,而夏季不明显,推测冬季悬浮体对现代浙闽涡旋泥质区形成有所贡献。

Inversion models of SSC are established based on the observed suspended sediment concentration（SSC）in the East China Sea in February 2007 and June 2015,in combination with the satellite images.It is found that the exponential inversion model is the best in use.The squared correlation coefficient is 0.971 and 0.856 for 2007and 2015 respectively.The results may well suggest the distribution pattern and control factors of the suspended sediment.It is also found that the near shore SSC is stronger than offshore one,and the winter one is higher than that in summer.In winter,the SSC ranges 10～28 mg/L in the Zhejiang and Fujian Coastal Current and 1.5～5mg/L in the Taiwan warm current.In summer,however,the SSC ranges 4～22mg/L in the Zhejiang and Fujian Coastal Current and 1.2～2.3mg/L in the Taiwan warm current.A SSC secondary front was found in the research in addition to the vortices found in the 40 m water depth in winter.However,the SSC secondary front and vortices are not so obvious in summer.According to the result,the winter suspended sediment may contribute more to the formation of the Modern Zhejiang and Fujian vortex mud area.