上游洪水对台风风暴潮过程期间长江口水位的影响研究

Study of flood's effects on the water level of the Yangtze Estuary area during the typhoon period

河口地区是河流与海洋相互作用的集中交汇区,也是上游洪水、天文潮和风暴潮等各种动力要素的综合作用区,该区域的水动力研究尤为复杂。长江作为我国第一大河,上游洪水对河口地区的影响尤其明显,特别是天文高潮、风暴潮与洪峰效应相叠加时(俗称"三碰头"),往往会对沿岸造成严重的海洋灾害。以长江大通水文站为上边界建立了一个适合于长江口地区的精细化天文潮、风暴潮和洪水耦合模型,通过对近年来影响长江口的典型台风风暴潮过程的模拟发现,耦合洪水后模型计算结果与实测更为吻合。通过理想数值实验,充分考虑天文潮、风暴潮和洪水的相互作用,定量分析了不同径流量对长江口不同区域的影响,并给出了在不同上游洪水流量和不同台风强度组合情景下,洪水对长江口地区水位的影响以及长江口地区可能出现的高水位。

Estuarine areas are the intersection area between rivers and ocean. They are also influenced by the upstream flood, astronomical tide and storm surges comprehensively, and hydrodynamic environment is particularly complicated in the region. As the largest river in China -Yangtze River, the impact of upstream flood on estuarine areas are particularly evident along the coast. It often causes serious marine disasters when the astronomical high tide, maximum storm surges and peak run off superimposed synchronously （commonly known as ＇ three meet＇ ） . An astronomical tide-storm surge-flood coupled model based on unstructured grid which regards Datong Hydrological Station as the upper boundary is utilized to simulate the high water level near the Yangtze River estuary areas. The results are more consistent with the measured data through the typical storm surge process. In order to quantitatively analyze flood＇s effect and interaction between the astronomical tide, storm surge and flooding. Numerical experiments are designed to analyze the possible high level and the flood and storm surge＇s contribution to total water level under different upstream runoff and typhoon intensity near the Yangtze River estuary area. It will provide important reference to the Yangtze Delta area＇s marine disaster mitigation.