黄河口泥沙输运三维数值模拟Ⅱ——河口双导堤工程应用

3-D simulation of the suspended sediment transport in the Yellow River mouth Ⅱ: Application to the double-dyke project

黄河口双导堤工程是继国家“八五”攻关项目:“延长清水沟流路行水年限”完成后提出的黄河口治理的重大工程设想。本文利用河口海岸三维数学模型(HEM-3D)对黄河口双导堤工程实施后河口高、中流量条件及低流量与东北风组合条件下的河口泥沙输送过程进行了数值计算。对比不同方案下的计算结果发现,当河口流量控制在1 500m3/s以上时,泥沙可以经由河口双导堤顺畅入海,在潮流作用下向导堤两侧输送,这对疏通河口拦门沙并进一步稳定黄河入海流路能够起到积极的作用。在低流量与东北大风的组合条件下,河口泥沙难以通过双导堤顺畅入海,大部分的泥沙可能会在导堤内部淤积。因此,在目前形势下如何通过水库调度保证充足的入海径流量是工程实施前需要深入研究的重要问题。

The double-dyke is an assumed framework proposed to deal with the sedimentation of the Yellow River mouth based on the conclusions of a previous state key project. With the 3-D model, the impacts of the double-dyke on the river sediment transport under the circumstances of different runoff and its combination with wind forces are assessed. As illustrated from the numerical results, the river runoff of 1 500 m^3/s should be a critical condition for the river sediment transport to the areas off the river mouth via the double-dyke. Under the circumstance of low river runoff combining with strong northeastern winds, most of the river sediment would deposit inside the dykes rather than being transported to the deep region through the double-dyke, which would have negative effect on the doubledyke and lower reaches of the river. Therefore, how to maintain a sufficient river runoff by the regulations of large reservoirs in the river basin becomes an important issue and needs more careful study.