海域水动力对老虎石海滩养护响应关系分析

Analysis of Hydrodynamic Response to Beach Nourishment at Tiger-Rock Beach

老虎石海滩的海滩养护工程包含三段滩肩补砂和两个吹填的水下沙坝式潜堤.采用软件Mike 21建立老虎石2维潮流和波浪数学模型.根据2011年水文波浪实测资料对数学模型进行了验证和计算效率评价,评价结果表明计算的潮位和潮流过程与实测值吻合较好,精度较高.重点研究了海滩养护对其近岸区域潮流和波浪的影响,得到沙坝坝身处是流速、波高变化最大的位置,受动力作用影响最大.吹填沙坝因波浪增高掀沙、潮流挟沙输运,可为其后方的海滩提供沙源补充.近岸区域潮流动力较弱,波浪变化较小,采用人工补砂和水下沙坝式潜堤双重整治的海滩养护工程对海滩上人工养护泥沙的保存非常有利.

Beach nourishment project, involving both beach nourishment and submerged sandbars construction, will be carried out on Tiger-Rock Beach. Based on finite volume method, the software Mike 21 is employed to establish a 2D flow and wave model of study area. Simulation results of the models are minutely verified by a comparison with the measured hydrodynamic data in 2011. Furthermore, the model efficiency is evaluated. Results show that the computation processes of tidal level, current coincide fairly well with field data, and with a high accuracy. This paperfocuses on the influence of beach nourishment project to the surrounding current and wave. The levee of the submerged sandbars, where is the largest variation of velocity and significant wave height occur, is an additional sand source for artificial filled sands backyard with the long-term dynamic loads. For the weak current and little wave change, the beach nourishment combining artificial filled sands and submerged sandbars is advantageous to save filled sands on the beach.