兴化湾海域泥沙特征及地形变化分析

摘要

In the aim of investigating the sediment characteristics and topography evolution in Xinghua Bay,the distribution characteristics of sediment and the effects of suspended sediment transport on topography evolution were analyzed based on measured data of hydrology and sediment in Xinghua bay in July,2013 and measured data of deep channels of Xinghua bay in the past years.Results show that sediment concentration is small in the study area,with the average sediment concentration only 0.062 kg/m3,and the average sediment concentration of spring tide is larger than that of neap tide.Moreover,sediment concentration changes obviously with tide fluctuation,and maximum concentration most appears when the velocity of rising tide reaches the maximum,while minimum concentration most appears when the velocity of falling tide reaches the maximum,indicating that sediment in the sea area is slightly disturbed.In addition,sediment discharge rates of rising tide are bigger than those of falling tide,but the absolute values of sediment discharge rate of two tides are very small.Finally,sediment in the area flows in and out with the tides,mainly transporting from the southeast to the northwest,which is the flow direction of rising tide.It accords with the phenomenon that width gradually expands in both sides of the deep channels near Bitou area and water depth is stable and increases a little,mainly in equilibrium with a bit more scouring.%为了查明兴化湾海域泥沙特征及地形变化,基于2013年7月份兴化湾海域水文泥沙测验资料,分析了研究区域的泥沙分布特性,并结合兴化湾深槽历年实测数据探讨了悬沙运移对其水下地形变化的影响.分析结果表明:测区含沙量较小,本次测验平均含沙量为0.062 kg/m3,大潮的平均含沙量较大,小潮的平均含沙量较小;含沙量的涨、落潮变化明显,最大含沙量多出现在最大涨急时刻附近,最小含沙量多出现在最大落急时刻附近,表明测验海域泥沙受到的扰动较小;各测点涨潮输沙率占优势,但涨、落潮输沙率绝对值都很小;研究海域泥沙随潮流往复进出,总体上为涨潮流方向,即由东南向西北运移,这与江阴壁头附近的情况相吻合,即深槽宽度不断向两侧扩展,而海底水深稳中有冲,基本处于略有冲刷的平衡状态.