Study of Variation trend of Suspended Sediment Concentration under Human Activity in the Yangtze Estuary
The concentration of estuarine suspended sediment is the foundation for maintaining the important factors of ecological security, while the recent projects such as reservoirs and water pumping lead to a sharp decrease of the suspended sediment concentration (SSC) in the waterfront sites especially those alluvial delta plain estuaries, which may bring side effects on the ecological security and estuarine health. This paper took the Yangtze estuary for example, analyzed the influence of human activity on the sea water content, sediment content and the regional transport situation, and discussed the influence of estuarine SSC variation on the ecological security elements. It was found that the estuarine SSC followed the transportation regulation of low-high-low, and the maximum value appeared in the turbidity maximum zone near the sandbar. With the increasing frequency of human activity, the amount of sediments entering the sea showed a significant decrease trend, and the estuarine SSC also reduced by approximately 24%, Due to the feeding and adjustment of re-suspension, this percentage was smaller than that of the sea entering suspended sediments. Meanwhile, the peak of SSC had shifted by one sixth longitude inward the estuary. In the nearby sea areas, the SSC was gradually decreasing towards the sea, and the differences among the seasons or tides were narrowing. Affected by the combined factors, the SSC in the upper and lower parts of north deep water channel experienced a downward trend, while the middle part was still able to maintain a relatively high SSC owing to the sand overlapping effect and the variation of local hydrodynamic power. This paper provides an important reference for the research relating to ecological security and estuarine health elements such as fishing, ion transport and planktons.
Human activity suspended sediment concentration trend and cause eco-safety Yangtze estuary
Y.T.Li Y.P.Yang
State Key Laboratory of Water Resources & Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
105-117
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）