黄河口及其邻近海域水深和岸线变化对M_2分潮影响的数值研究

A Numerical Study on the Effect of Changes in Water Depth and Coastline on M_2 Tidal Component Near the Yellow River Estuary

黄河口及其邻近海域水深和岸线的演化显著地影响着该海区的潮波系统。本研究收集到了1972年及2002年水深及岸线数据。在此基础上,基于ROMS模式建立了渤海海域潮波数值模式,模式采用正交曲线坐标,在黄河口及其邻近海域水平分辨率优于500m,其它海域水平分辨率优于2km。模式首先模拟了2002年M2分潮潮波状况,并利用实测资料进行了检验,在此基础上进一步模拟了1972年M2分潮潮波状况。对比分析表明1972—2002年黄河口外M2分潮无潮点向东北方向迁移约30km;期间莱州湾西侧M2分潮振幅明显增强;莱州湾M2分潮迟角呈现由前进波向退化的旋转潮波系统转变的趋势。

Based on the data of water depth and coastline collected in the area near the Yellow River Estuary in 1972 and 2002, the effects of variations in water depth and coastline on M2 tidal component in the study area are studied and a tidal wave numerical model, which uses the orthogonal curvilinear coordinates, is established for the area of the Bohai Sea on the basis of ROMS model. The horizontal resolution of this model is superior to 500 m in the Yellow River Estuary and its adjacent areas and to about 2 km in other areas. The M2 tidal wave system in the study area in 2002 is firstly simulated based on the model and the results thus obtained are examined with the measured data. Then, the M2 tidal wave system in 1972 is simulated with the same model. Comparison of the two numerical results indicates that the amphidromic point of M2 in the area out of the Yellow River mouth moved about 30 km northeastward in the period from 1972 to 2002. During this period, the amplitude of M2 tide component at the western side of the Laizhou Bay intensified obviously and the phase lag of the M2 in the bay showed a trend of transforming from progressive waves to a degraded amphidromic system.