南海北部海底沙波迁移规律及其在台风作用下的响应研究

Research on the migration rule and the typhoon impact on the submarine sand waves of the northern South China Sea

本文在南海北部海底沙波已有研究的基础上,总结分析了研究区表层沉积物以及沙波的形态、分布、迁移特征;使用区域海洋模式(ROMS)模型模拟了研究区2010-2011年的底部流场数据;利用Rubin公式模拟计算了海底沙波的迁移规律,并与搜集所得资料进行对比分析;结合台风资料及底流数据,分析了台风对海底沙波运移的影响。研究结果显示:海底沙波运移方向的计算结果与搜集所得资料比较吻合,均为向东向南方向;不同站点的迁移距离在0~21.8 m之间,且为往复累积的结果。这表明:Rubin公式在ROMS模型模拟所得底流资料的支撑下,可以再现海底沙波的迁移过程。模拟计算的研究区内两个站位在"凡亚比"台风影响期间的迁移距离分别为2.0 m、2.9 m,分别占其年运移量的9.17%和26.36%,说明台风过境能对海底沙波的迁移产生重大的影响。

Submarine sand waves,vital to seabed stability,are an important consideration for oceanic engineering projects such as oil pipe lines and submarine cables. The properties of surface sediment and the evolvement of submarine sand waves in a specified area in the South China Sea are studied using both a hydrological model and field observational data. The bottom flow field data between 2010 and 2011 in the study area are simulated by the Regional Ocean Model System（ ROMS）. The migration of submarine sand waves is calculated using Rubin＇s formula along with typhoon data and bottom flow field data,which allows for the analysis of sand wave response under the influence of typhoons. The migration direction calculated by Rubin＇s formula and bottom flow are very similar to collected data.The migration distance of different positions is between 0. 0 m and 21. 8 m,which reciprocates cumulatively. This shows that Rubin＇s formula can predict the progress of submarine sand waves with the bottom flow simulated by ROMS. The migration distances of 2 sites in the study area are 2. 0 m and 2. 9 m during the Typhoon ＂Fanapi＂. The proportion of the calculated migration distance by the typhoon is 9. 17% and 26. 36% of the annual migration distance,respectively,which proves that the typhoon can make a significant impact on submarine sand waves.