洪泽湖退圩还湖前后调蓄能力模拟及对比分析

Simulation and Comparative Analysis of Change of Regulating and Storage Capacity of Hongze Lake Before and After Returning Polder Area to Lakes

为分析退圩还湖对洪泽湖防洪调蓄的影响,构建了洪泽湖的二维水动力模型,模拟退圩还湖前后多情景不同水平年洪水出入湖流量过程及湖区水位、流速,分析了退圩还湖后调蓄能力的变化。结果表明,洪泽湖退圩还湖后,10年一遇、20年一遇的中小型洪水的调蓄系数分别增加0.03、0.04,削峰系数分别增加0.03、0.03,高于50年一遇大洪水的0.02、0.02;10年一遇、20年一遇、50年一遇洪水下,蒋坝站最高洪水位分别下降0.12、0.14、0.09 m,蒋坝站出现最高洪水位时湖区水位差和流速差在20年一遇洪水下变化最大。表明退圩还湖增强了洪泽湖的调蓄能力,对中小型洪水的调蓄效果更加显著,特别是20年一遇的洪水。研究结论可为淮河下游地区的防洪调蓄提供技术支持和理论参考。

In order to analyze the influence of returning polder area to lakes on flood control and storage capacity of Hongze Lake,a two-dimensional hydrodynamic model was established to simulate the flow process of flood in and out of the lake at different levels and the water level and velocity,and to analyze the change of flood control and storage capacity.The results show that after the returning polder area to lakes of Hongze Lake,the regulation and storage coefficients of the once-in-a-decade and once-in-20-year floods increase by 0.03 and 0.04 respectively,and the peak shavingt coefficients increase by 0.03 and 0.03 respectively,which are higher than the once-in-a-50-year floods of 0.02 and 0.02,respectively.The maximum flood water level of Jiangba station decreased by 0.12 m,0.14 m and 0.09 m respectively under the condition of a 10-year,20-year and 50-year flood.When the maximum flood water level of Jiangba station appeared,the difference of water level and velocity in the lake area changed the most under the condition of a 20-year flood.The returning polder area to lakes enhances the regulation and storage capacity of Hongze Lake,but it is more significant for small and medium flood,especially for the flood that occurs once in 20 years.The conclusions can provide technical support and theoretical reference for flood control and storage in the lower reaches of Huaihe River.