基于FVCOM的厦门湾及其周边海域三维潮流数值模拟

Three dimensional tidal current numerical simulation based on FVCOM in and around Xiamen Bay

基于非结构三角形网格、干-湿判别技术和有限体积法的FVCOM(finite volume coastal oceanmodel)海洋数值模式,建立了厦门湾及其周边海域高分辨率(30 m)的三维潮汐、潮流数值模型.模拟结果同该海域2个验潮站和4个连续海流站的观测资料符合良好,较好地反映了厦门湾及其周边海域潮汐、潮流运动的变化状况和分布特征,并给出了M2、S2、K1、O1共4个主要分潮的同潮图、表层潮流椭圆、最大可能潮流流速及表、底层潮余流分布.厦门湾及其周边海域属正规半日潮类型,4个分潮的最大潮汐振幅分别为200、65、36、29 cm,厦门湾内外迟角差分别为20°、25°、18°、10°;镇海角至围头角连线东南侧湾口区为逆时针旋转的驻波,西北侧湾内为前进潮波.湾内潮流属正规半日潮流,湾口区潮流以逆时针方向的旋转流运动为主,湾内各水道为往复潮流,椭圆长轴与水道走向一致,4个分潮流表层最大流速分别为201、51、34、25 cm/s;九龙江口区3条港道内的流速以南港最大;表层余流大于底层余流,二者水平分布形态基本一致,都为北进南出.

A 3-D high-resolution（30 m） hydrodynamic model was established using an unstructured triangular grid,dry/wet identification technology known as the finite-volume coastal ocean model（FVCOM） to study the tides and tidal currents in and around Xiamen Bay.The simulation results were in good agreement with the in situ data.The co-tidal charts of the four main constituents（M2,S2,K1 and O1）,the surface tidal current ellipses,and the maximum probable tidal current velocities and surface and bottom tidal residual current distribution were plotted to describe the temporal and spatial distribution of the tides and tidal currents in the studied areas.Xiamen Bay has a regular semi-diurnal tide,with maximum amplitudes of the four constituents reaching 200cm,65cm,36cm and 29cm,and differences in the phase-lag between the inner and outer bay of 20°,25°,18° and 10°,respectively.Anticlockwise standing waves are found in the southeastern part of the bay（Zhenhaijiao-Weitoujiao line）,while progressive waves are found in the northwestern part.The studied areas are dominated by regular semi-diurnal tidal currents in which the current rotates anti-clockwise at the mouth of the bay and flows rectilinearly along channels in the northwestern part of the bay.The direction of the major axes of the tidal current ellipse is concordant with the local morphology.The maximum surface current speeds can reach 201 cm/s,51 cm/s,34 cm/s,and 25 cm/s for M2,S2,K1,and O1,respectively.Compared with other channels,South Port has the greatest surface current speed in Jiulongjiang Estuary.The residual current at the surface is greater than at the bottom,but their distribution patterns are basically consistent,coming into the bay in the north,flowing out in the south.