汇泉湾水动力环境观测和数值模拟研究

THE HYDRODYNAMIC CONDITIONS AND NUMERICAL MODELING OF THE HUIQUAN BAY

汇泉湾是青岛市最主要的海水浴场,湾区浴场的沙滩沙质退化及细沙流失现象一直备受关注。本研究旨在研究上述现象的成因,为汇泉湾生态环境保护和可持续发展提供科技支持。我们于2015年1月和9月在汇泉湾进行了水文、泥沙和悬浮物的综合观测,并基于FVCOM建立了汇泉湾高分辨率的水动力模式,模拟了汇泉湾及其临近海域的水动力环境。结果显示:汇泉湾常年存在一顺时针(即反气旋)环流,它有利于携带泥沙从湾的西侧进入而从东侧流出;环流中心区流速弱,泥沙不容易被带走,沉积物粒径较小。汇泉湾海域沙滩沙质粗化且流失的原因主要为:波致流引起的沿岸输沙将湾口西侧岩石剥蚀的较粗的细砂和粉砂搬运至浴场沙滩,而较细的泥沙容易地从东侧流出湾区。

Huiquan Bay is one of the most important beaches of Qingdao. However, the beach degeneration and sand erosion have raised the high attention of scientists. We aim to study the cause of the problem, find the solution, and provide a technical assistant to the ecological environment protection and sustainable development of the bay. A comprehensive survey in terms of hydrodynamics and sediment was conducted in January and September 2015 in the bay. A high-resolution current-wave-coupled model was developed based on the FVCOM （Finite-Volume Community Ocean Model）. The survey and the numerical model result analysis shows the following. There is a strong clockwise （anti-cyclonic） circulation that brings mud and sand into the bay in the west and out of the bay in the east. The diameter of the sediment with the circulation current is large. The current in the center of the anti-cyclonic circulation is weak and are unable to carry on sediment. The main reason of the beach degeneration and erosion in the Huiquan Bay is due to an along-coast sand transportation caused by wave and wave-induced current, by which the sands are moved from the bay in the west to the swimming beach, and the finer mud and sand are moved out of the bay at the east corner of the bay.