三门湾猫头深潭对“烟花”台风的冲淤响应

Scouring and silting response of Maotou deep pool in Sanmen Bay to Typhoon In-Fa

极端台风天气下,台风浪可能会造成海湾泥沙大幅起悬,从而引起湾内深槽骤淤。以浙江中部三门湾为研究对象,建立波流共同作用下的泥沙冲淤数学模型,研究猫头深潭在台风“烟花”过境期间可能产生的泥沙骤淤风险。经验证,数学模型较好地复演了“烟花”台风过程中的风暴潮与台风浪过程。研究结果表明,在台风浪作用下,下洋涂南侧浅滩及猫头深潭南北侧浅滩的含沙量均有明显增加,局部可增加至无浪情况下的3倍以上,“烟花”台风使猫头深潭最大淤积达0.15 m。台风浪导致的含沙量增加是三门湾深潭骤淤的主要原因。

Under extreme typhoon weather,typhoon waves may cause large suspended sediment in the bay,resulting in sudden siltation of the deep trough in the bay.Taking the central parts of Zhejiang province as the research object,this paper predicts the amount of the sediment deposition in Maotou deep pool with the influence of Typhoon In-Fa.To answer this question,a mathematical model of sediment erosion and deposition under the combined action of waves and currents is established.The mathematical model reproduces the storm surge and typhoon wave process.The results show that under the action of typhoon waves,the sediment concentration in the south shoal of Xiayangtu and the north and south shoals of Maotou deep pool increases significantly,which can be increased by more than three times in some part,the maximum siltation of Maotou deep pool is 0.15 m.The increase of sediment concentration caused by typhoon wave is the main reason for the sudden siltation of Sanmen Bay deep pool.