波流对人工岬头和海滩养护工程的响应

Responses of Wave and Current to Artificial Headlands and a Beach Nourishment Project

摘要:

以新开河口至南山岸线为研究对象，为减少海岸侵蚀，在岸线两端修建人工岬头和包含水下沙坝的海滩养护工程.基于MIKE 21软件建立潮流和波浪耦合模型，研究波流动力对人工岬头和海滩养护工程的响应变化.人工岬头的挑流作用使得东西岬头前流速增加，但岬湾内部流速减小并在岬头后侧形成弱环流.海滩养护工程后沙坝坝顶有效波高略有增加，但沙坝之间有效波高有所削减，沙坝后侧海域波高明显减少；滩肩前方海域有效波高减小，涨潮期间波高减小量大于落潮期间波高减小量.人工岬头和海滩养护工程的共同作用可有效削减岬头和沙坝环抱海域特别是近岸的潮流和波浪，减少海岸侵蚀.

Abstract:

Taking the coast from the Xinkai estuary to Nanshan as a study object, the artificial headlands and a beach nourishment project including underwater sandbars will be constructed to reduce coastal erosion. MIKE 21 was employed to establish tidal current and wave model, hence the responses of current and wave to artificial headland and beach nourishment project can be obtained. The velocity in front of headlands can be increased due to jetlikeflow, however, the velocity inside of the headlandbay is decreased, and a weak circulation appears in the back of the headland. After the beach nourishment, wave height increases at the crest of sandbar, while it decreases between and behind sandbars with more decreasing behind sandbars. Wave height decreases in front of the berm, and has more reduction during flood period than ebb period. The combined effect of artificial headland and beach nourishment project can effectively reduce the tidal currents and waves in the area encircled by headlands and sandbars, especially near shore, hence reduce coastal erosion.