夏季波浪对钦州湾水交换能力的影响研究

Study on the Influence of Summer Wave on Water Exchange Capacity in Qinzhou Bay of China

关键词:  水交换能力  半交换时间  波浪  数值模拟  钦州湾

Key words:  water exchange capacity  half exchange time  wave  numerical simulation  Qinzhou Bay

摘要:

基于无结构三角网格的FVCOM海洋模式，以K1、O1、P1、Q1、M2、S2、N2和K2这8个分潮调和常数为驱动，考虑钦江和茅岭江两条径流，建立了钦州湾海域的高分辨率三维水动力数值模型。通过与实测数据的对比，该模型可以较好地模拟钦州湾海域的水动力特征。在此基础上叠加浪流耦合模块和DYE-RELEASE模块，模拟了夏季波浪对钦州湾海域流场结构以及水交换能力的影响。结果表明：波浪对钦州湾海域流场的影响，涨急和落急潮流场的变化不显著，而涨憩尤其是落憩时，钦州湾的流速明显增大。钦州湾在潮汐径流作用下的半交换时间为14.3 d，在潮汐径流波浪作用下的半交换时间为4 d。内湾茅尾海的水体交换主要受制于潮汐和径流，而外湾钦州湾的水体交换受制于潮汐和波浪。

Abstract:

Based on finite-volume coastal ocean model with unstructured triangular grid, driven by eight harmonic constants of tidal components K1, O1, P1, Q1, M2, S2, N2, and K2, considering the two runoffs of the Qinjiang River and the Maoling River, a high-resolution three-dimensional hydrodynamic numerical model for Qinzhou Bay waters was established. By comparison with the observed data, the model can better simulate the hydrodynamic characteristics of the Qinzhou Bay waters. On this basis, wave-current coupling module and DYE-RELEASE module were merged to simulate the influence of summer wave on the current field structure and water exchange capacity of Qinzhou Bay waters. The results show that the impact of waves on current field in Qinzhou Bay waters is not significant at the time of maximum flood and maximum ebb, but the current velocity of Qinzhou Bay increases significantly at the time of flood and ebb slack, especially at the time of ebb slack. On the average, the half exchange time of Qinzhou Bay under the effect of tidal runoff is 14.3 d, and the half exchange time under the effect of tidal runoff and wave is 4 d. Water exchange in the inner bay of Maowei Sea is mainly subject to tides and runoff, while water exchange in the outer bay of Qinzhou Bay is subject to tides and waves.