Distributions of Suspended Sediment Concentration in the Yangtze Estuary and Coastal Seas in Spring

The spatial distributions of suspended sediment concentration (SSC) in spring from 2007 to 2011 were analyzed in the Yangtze (Changjiang) estuary and coastal seas using remote sensing data of MODIS. The results indicated that high concentration areas of SSC did not directly surround the Yangtze estuary but concentrated northwards considerably along the coast about 100km. The driving of Taiwan warm current, the southward drift of SSC along the coast and also the river discharges should be the mixed reasons for this northward concentration of SSC. The coastal current also drove the SSC along the coast to the high concentration area of SSC. The first EOF pattern, demonstrated by EOF analysis, explains the dominant distribution pattern of SSC in the study area. This controlling pattern should be caused by the joint effects of northeast wind, the coastal current and Taiwan warm current. The SSC dispersed and extended with a wide range from 122 degrees E to 126 degrees E (about 400km), and from 30 degrees N to 34 degrees N (about 440km). SSC in spring of 2010 and 2011 was obviously higher than that in the previous three years. It suggested that the suspended sediment and associate contaminant, discharged from the Yangtze River, was increasing in recent two years. Stronger northeast wind has significant and negative influence on the SSC.