VARIATION OF SUSPENDED SEDIMENT CONCENTRETION IN OFFSHORE YANGTZE ESTUARY

Hydrologic and sediment data from 2007 to 2009 were analyzed and discussed on the variation of tide current and suspended sediment concentration in the offshore Yangtze estuary. The results show that the sediment concentration was significantly higher in winter rather than in summer; tide current is increasing year by year in the spring tide period,but in the neap tide period tide current increases in the beginning and decreases later on. In the nearshore region,the sediment concentration increases first and then decreases in spring tide period,and deceases year by year in neap tide period. However,in the offshore region,the sediment concentration always increases year by year in spring and neap tide period. The sediment concentration exhibits obvious periodical changes. It is much higher in spring tide period than that in neap tide period. The peak value of sediment concentration commonly lags behind the peak value of current.