Intratidal+and+neap-spring+variations+of+suspended+sediment+concentrations+and+sediment+transport+processes+in+the+North+Branch+of+the+Changjiang+Estuary.pdfVIP

Acta Oceanol. Sin., 2015, Vol. 34, No. 1, P. 137–147 DOI: 10.1007/s13131-015-0605-z E-mail: hyxbe@263.net Intratidal and neap-spring variations of suspended sediment concentrations and sediment transport processes in the North Branch of the Changjiang Estuary 1 2 1 1 1 LI Zhanhai *, LI Michael Z , DAI Zhijun , ZHAO Fangfang , LI Jiufa 1 State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China 2 Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, Dartmouth, B2Y 4A2, Canada Received 18 November 2013; accepted 4 June 2014 ©The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2015 Abstract Profiles of tidal current and suspended sediment concentration (SSC) were measured in the North Branch of the Changjiang Estuary from neap tide to spring tide in April 2010. The measurement data were analyzed to determine the characteristics of intratidal and neap-spring variations of SSC and suspended sediment transport. Modulated by tidal range and current speed, the tidal mean SSC increased from 0.5 kg/m3 in neap tide to 3.5 kg/m3 in spring tide. The intratidal variation of the depth-mean SSC can be summarized into three types: V-shape variation in neap tide, M-shape and mixed M-V shape variation in medium and spring tides. The occurrence of these variation types is controlled by the relative intensity and interaction of resuspension, settling and impact of water exchange from the rise and fall of tide. In neap tide the V-shape variation is mainly due to the dominant effect of the water exchange from the rise and fall of tide. During medium and spring tides, resuspension and settling processes become dominant. The interactions of these processes, together with the sustained high ebb current and shorter duration of low-tide slack, are respon- s