近海人工岛及沙坝工程与潮流的响应特征研究

北戴河新区位于最具发展潜力的环渤海经济圈中心地带,为满足旅游业发展需要而建的人工岛和保护旅游海滩而建的人工沙坝对近海潮流动力有不同程度的影响。该文基于MIKE21 FM模块通过大、中、小模型三层嵌套的方式建立洋河-葡萄岛近岸海域潮流数学模型,研究分析人工岛及沙坝工程建设前后的潮流动力变化特征,得到下列主要结论:工程建设后研究区域的主体潮流特征仍为顺岸往复流,流速变化量涨潮大于落潮;人工岛工程对流速场的影响范围和程度均明显大于沙坝工程,其中人工岛工程引起的流速变化量是沙坝工程的4倍;人工岛的建设使其内部形成一个相对封闭的水域,流速近乎为零,而养滩工程区在两侧水工建筑物和水下人工沙坝的掩护作用下流速基本减小至0.10 m/s以下。

Study on responses of tidal currents to artificial island and sandbars in coastal waters

Beidaihe New District locates in the central of the Bohai economic circle that has huge developing potential.In order to meet the requirements of tourism development and protect tourist beach,the artificial island and sandbars have been built,which has certain influence on tidal currents in coastal waters.A tidal current numerical model was set up by MIKE21 FM module using a three-layer nested grid system,which was used to reproduce and analyze the current fields before and after the projects.The numerical results show that after the construction,tidal current remains reciprocating flow and the variation of current velocity in the flood period is larger than that in the ebb period;the construction of the artificial island has a further influence than the artificial sandbars,and the variation of velocity induced by the former is four times of the latter;the construction of the artificial island makes its basin be a relative closed waters,so that the velocity is almost zero inside of the basin.In zone of beach nourishment,the tidal current reduces to less than 0.10 m/s because of the hydraulic structures in both sides and artificial sandbars.