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基于温州瓯飞浅滩海域2011、2013和2014年7个站点大、小潮垂向同步连续海流和悬沙浓度等观测资料,分析了该海域悬沙浓度的时空变化特征及其影响因素,并利用Morlet小波分析方法探讨了悬沙浓度变化与潮流间存在的多种周期变化;同时对该区域因围填工程前后导致的悬沙浓度变化做了回顾性分析。分析结果表明:(1)悬沙浓度在平面分布上符合“近岸高,外海低”的一般规律,在瓯江与飞云江两个河口存在悬沙高浓度区。悬沙浓度垂向分布大致呈准直线、斜线、抛物线和混合型4种类型变化;(2)河口处潮流为往复流,悬沙浓度出现4次峰值。悬沙浓度的峰值滞后于流速峰值1~2小时。由岸及远,潮流呈旋转流,悬沙浓度峰减弱并且峰数减少;(3)悬沙浓度变化同潮流变化周期密切相关,存在4、6和12小时的周期性变化,浅水分潮主要影响的是中底层的悬沙变化,对表层悬沙变化影响较小;(4)随工程进行,区域悬沙分布时空特征并未发生大的变化,但局部地区的工程影响不可忽略,近工程站点悬沙浓度都有增加趋势,瓯江南口大潮和小潮间的悬沙浓度变化加剧。
Based on the observed data of the vertical synchronous continuous current and suspended sediment concentration at seven stations in 2011, 2013 and 2014 in the sea of Oufei Shoal, Wenzhou, the spatio-temporal variations of suspended sediment concentration and its influencing factors were analyzed. Morlet Wavelet analysis method is used to investigate the variation of suspended sediment concentration and the variety of periodic variations existing in the tidal current. At the same time, the change of suspended sediment concentration in the area before and after the reclamation project is analyzed retrospectively. The results show that: (1) The suspended sediment concentration is consistent with the general law of “high in nearshore, low in outer sea” in plane distribution, and high concentrations of suspended sediment exist in the estuary of Oujiang River and Feiyun River. Vertical distribution of suspended sediment concentration is roughly quasi-linear, diagonal, parabola and mixed-type changes in four types; (2) the trend of estuary reciprocating flow, suspended sediment concentration 4 times the peak. The peak of suspended sediment concentration lags behind the peak of flow rate for 1 ~ 2 hours. From the shore and the distance, the tidal current is in a swirling flow, the suspended sediment concentration peak is weakened and the number of peaks is reduced. (3) The change of suspended sediment concentration is closely related to the tidal flow changing period, with periodic changes of 4, 6 and 12 hours. (4) As the project progressed, the spatial and temporal characteristics of suspended sediment distribution in the area did not change much, but the impact of the project in some areas could not be neglected. The near-project Site suspended sediment concentrations have an increasing trend, Oujiang Jiangnan tide and the tide between the concentration of suspended sediment increased.