口外岸线变化对茅尾海潮流动力及水体交换的影响

2005年以来，钦州湾口外围填海规模近3000 hm2，岸线变化十分显著，对其上游茅尾海潮流动力及水体交换产生了一定影响。本文通过建立钦州湾-茅尾海二维潮流数学模型，从潮流特征、纳潮量、水体交换周期等方面探讨了2005~2015年间钦州湾岸线变化对茅尾海潮流动力及水体交换的影响，其中，水体交换周期以总负荷的半交换时间表征，避免了单点浓度半交换时间表达中采样点位置不同导致的偏差，以及平均浓度表达中不同时刻水体体积差异带来的误差。研究结果表明:口外岸线变化使钦州湾湾口进一步缩窄，纳潮容积减小，茅尾海潮流流速和潮差减小，潮量减小1.30%~1.53%，半交换周期增加51 h，潮流动力及水体交换能力均有所减弱。

Impacts of the shoreline change in Qinzhou bay on the tide and water exchange of Maowei sea

Since 2005, nearly 3000 hm2 water area were reclaimed in Qinzhou bay, change of shoreline is very significant.By a 2D numerical simulation of tidal current in Qinzhou bay, influence of shoreline change on dynamics and water exchange in Maowei sea, upstream of Qinzhou bay were discussed form aspect of tide current characteristics, tidal flux and water change, etc.Among them, the exchange period of water is characterized by a half exchange time of total load, to avoid the deviation caused by position of sampling points in single point concentration half exchange time, and the deviation caused by water volume difference at different tide period in average concentration half exchange time.The results show that:by the change of shoreline, mouth of Qinzhou bay narrowed further and tidal volume of it decreased; to the Maowei sea, the tidal range and flow velocity decreased, the tidal flux diminished 1.30%~1.53%, and the half-exchange period increased 51 hours, the tide and water exchange capacity were weakened.