长江口徐六泾水域余流及潮流垂直结构变化规律研究

Residual Current and Tidal Current Vertical Structure in Tidal Reach of Yangtze Estuary

基于长江口徐六泾断面3个测站2011年春、夏、秋3个季节对应的不同径流量下的ADCP流速剖面数据,采用调和分析方法对徐六泾感潮河段的余流和潮流进行分离。研究表明,余流流速变化规律与长江口径流流量季节性变化一致,各测站流向沿水深变化平稳,基本与河岸线平行;潮流椭圆极化严重,几乎接近于直线,且基本与河岸线平行;潮流振幅和倾角的垂直变化和季节变化规律与余流的流速和流向的变化规律一致,即潮流的强度与径流强度呈正相关,且潮流椭圆的倾角变化幅度与平均流速变化幅度基本一致。

Based on the ADCP velocity data of three stations in the Xuliujing section of the Yangtze Estuary in spring,summer and autumn,the residual flow(runoff)and tidal current in the tidal reach of the Yangtze Estuary are separated by harmonic analysis method.The results showed that variation of residual flow velocity is consistent with the seasonal variation of runoff in the Yangtze Estuary,and that the flow direction of each station changes steadily along the water depth,basically parallel to the riverbank line.The elliptical polarization of tidal current is serious,almost close to the straight line,and basically parallel to the riverbank line.The vertical and seasonal chang laws of tidal amplitude and inclination are both consistent with those of the flow and direction of residual current.That is,the intensity of tidal current is positively correlated with the intensity of runoff,and that the variation range of inclination angle of tidal current ellipse is basically consistent with that of average velocity.