长江入海径流变化对河口盐水入侵影响分析

Analysis on the impact of runoff variation on saltwater intrusion in Yangtze River Estuary

将河口海岸三维斜压水流数值模式应用于长江口海域，对长江口深水航道整治工程后枯季大通流量在6000～40000 m3／s的18组分级流量情况下的盐水入侵影响范围和影响程度进行了模拟计算。结果表明：上游径流对盐水入侵有明显的制约作用，随着上游径流量增加，盐水入侵的范围改变显著；利用大通流量和河口代表点半月最大盐度进行回归分析，得到半月最大盐度与大通流量呈现良好的指数关系，相关系数高于0．99。

A 3D estuarine and coastal baroclinic numerical model was set up and applied to the Yangtze River Estuary.18 groups of numerical experiments were conducted to simulate the scope and impact of saltwater intrusion with different upstream runoff between 6 000-40 000 m3/s in dry season after the Yangtze Estuary Deep-water Channel Regulation Project.The results show that the upstream runoff has an obvious restraining effect on the saltwater intrusion.With the increase of the upstream runoff, the range of saltwater intrusion changes significantly.Through the regression analysis between runoff and maximum salinity of the representative point in half month,a good exponential relationship was obtained,and the correlation coefficient was more than 0.99.