长江口不同径流量对潮波传播的影响

Influence of different runoffs on tidal wave propagation at Yangtze River estuary

采用在河口地区应用比较成熟的ADI法建立数学模型,复演长江口潮波传播过程。纵向分析了潮差、涨落潮历时、潮位过程线及高低中潮位的变化规律。分析结果表明：长江口潮波季节性变化明显,与径流量关系密切。径流量越大,在其影响范围内潮差越小,涨落潮历时比越小,潮波变形越严重。横向分析了河道南北两岸潮差的变化,结果表明：北岸潮差比南岸潮差大5~7 cm,径流量变化不改变长江口横向潮差北岸大于南岸的趋势。

We simulate the tidal wave propagation process in Yangtze estuary with ADI model which has been widely used in estuary areas.The longitudinal tidal range,the durations of tide rising and ebbing,the tidal level hydrograph and variation laws of high tide,low tide and middle tide are analyzed.The results show that the seasonal change of tidal wave propagation in Yangtze estuary is obvious and is closely related with runoff volume.The larger the runoff volume is,the smaller the tidal range and duration ratio of tide rising and ebbing are,and the more obvious deformation of tidal wave is.The transversal difference of tidal range between south and north shore is analyzed.The results show that the tidal range of north shore is 5~7cm higher than that of south shore and this law is not influenced by runoff volume.