广西沿海潮汐特征分析

Analysis on Tidal Characteristic of Guangxi Coast

利用最新潮汐模型FES2014提取广西沿海K_1、O_1、M_2和S_2等4个主要分潮调和常数,计算潮汐类型,并绘制广西沿海潮波图及潮汐类型分布图。结果表明:广西沿海潮波传播方向为西南向东北方向;潮汐类型以正规日潮为主;北部湾东北部为不正规日潮混合潮。根据北海、防城港、龙门港及钦州航道等4个重要验潮站的实测数据,采用最小二乘原理的调和分析方法得到4个验潮站的调和常数。根据调和常数计算潮汐特征值,结果表明4个验潮站潮汐类型均为正规日潮,这与模型分析结果是一致的。利用北海长期验潮站分析得到北海站设计高水位约为470 cm,设计低水位约为110 cm。通过潮波图与水下地形分布图的比较,表明广西沿海潮汐的形成与水下地形分布密切相关。

Four main harmonic constants of K1, Q, M2, S2 in the Guangxi coast are extracted, the tidal types are calculated with the latest tide model FES2014, and the tidal wave chart and tidal type distribution chart are drawn. It is shown that the direction of tidal wave propagation in the Guangxi coast is southwest to northeast. The tidal type is dominated by regular diurnal tide, and the northeastern Beibu Gulf is irregular diurnal tide. The harmonic constants are calculated by the least square methods based on the measured data of four important tide gauge stations, such as Beihai, Fangchenggang, Longmengang and Qinzhou Channel. Based on harmonic constants, the tidal characteristic values are calculated. It is show that the tidal types are regular diurnal tide in four tide gauge stations, which are consistent with the model analysis results. According to the Beihai long-term tide gauge station, the design high water level of Beihai station is about 470 cm and the design low water level is about 110 cm. The comparison between the tidal wave chart and the underwater topographic map shows that the formation of tide in the Guangxi coast is closely related to the distribution of underwater topography.