废黄河口海域潮流动力与悬沙输运特征

The relationship between the suspended sediment movement and tidal current dynamic characteristic in Old Yellow River Delta

根据2006年废黄河口海域的悬沙、流速、流向的观测资料,应用短期资料的潮流准调和分析方法,对连续海流资料进行了分析,并结合悬沙资料,对悬沙质量浓度与潮流之间的动力关系进行了探讨。研究结果表明:该海域潮流属于正规半日潮流,潮流以往复流为主,离岸越远,旋转性越强;涨潮流流向以SSE为主,落潮流流向以NNW为主。悬沙质量浓度呈现近岸悬沙质量浓度高,向海逐渐降低的分布形态;悬沙质量浓度的垂直变化,从表层到底层由小到大,近岸悬沙质量浓度垂向梯度较大。悬沙质量浓度出现明显的周期性变化,悬沙质量浓度的峰值基本与海域半日潮流特点相对应,悬沙质量浓度的峰值一般出现在流速峰值之后。海域的悬沙在潮流作用下主要向南输运,与涨落潮的方向基本一致,涨潮单宽输沙量均大于落潮单宽输沙量。

Based on the observation data of suspended sediment concentration （SSC） and ocean current, we applied the tidal current quasi-harmonic method for short-term data to analyze the tidal current characteristics, and to discuss the dynamics relation between SSC and the tidal current. The research results show that the tidal current in the studied area can be classified as regular semidiurnal tidal current. The north component of semidiurnal current is generally stronger than the east one. The tidal current is mainly the rectilinear. As the distance is farther away from the shore, the rotation is stronger. At flood tide, the tidal current is in the direction of SSE, and at ebb tide, the cur- rent is in the direction of NNW. The SSC gradually reduces from the nearshore to Offshore, and it increases from surface to bottom. The SSC vertical gradient in nearshore is larger than in offshore. The SSC shows obvious cyclical changes, in response to regular semidiurnal tidal currents. The maximum SSC appears after the maximum velocity. The suspended sediment mainly is transported in direction of south by tidal current, and the sediment discharge of the flood tide is larger than the ebb tide.