淮河流域冯铁营引河工程的防洪效果及影响评估

Flood control effect and impact assessment of Fengtieying Diversion Project in Huaihe River Basin

淮河流域冯铁营引河工程是扩大淮河洪水出路、减轻中游洪涝灾害的关键性工程,针对引河建成后淮河及洪泽湖的防洪情势的调整问题,需要进行综合评估。以现状及规划蚌埠至洪泽湖河段防洪工程体系为基础,构建了一维和二维耦合、河道-湖泊-蓄滞洪区为一体的水动力数学模型,分别在设计洪水及典型洪水的条件下,通过分析水位、流量、比降等水动力因素的变化,客观评价了引河工程的防洪效益及影响。评价结果表明:①该工程有效降低了淮河干流的水位,缩短了高水位历时,减轻了中游地区的洪涝灾害;②该工程调整了淮河干流的沿程水面比降,提高了浮山以上河段的造床能力;③在入海水道二期工程的作用下,引河分洪对下游的影响主要局限在冯出口附近,而且可以通过优化调度使其影响减轻甚至消除,不会增加洪泽湖防洪排涝的负担。研究成果可为河湖一体化治理提供参考。

Fengtieying Diversion Project is a crucial project to expand the flood outlet of the Huaihe River and reduce flood disasters in the middle reaches.After the completion of the diversion channel,the flood control situation of the Huaihe River and Hongze Lake requires a comprehensive assessment.Based on the current situation and planning of the flood control engineering system in the section from Bengbu to Hongze Lake,this paper established a hydrodynamic mathematical model coupling1D and 2D and integrating river-lake-storage detention basin.Under the conditions of designed flood and typical flood,the flood control benefit and impacts of the project were objectively evaluated by analyzing the changes of hydrodynamic conditions such as water level,flow and water surface slope.The evaluation result showed that:①the project effectively reduced the water level of the mainstream of the Huaihe River,shortened the duration of high water level,and reduced flood disasters in the middle reaches area.②The water surface slope of the mainstream of the Huaihe River could be increased,improving the bed-forming capacity of the upstream of Fushan section.③Under the effect of sea-entering channel phase Ⅱ project,the influence of diversion project was mainly limited at the Fengchukou section,which could be alleviated and eliminated by optimal operation without increasing flood risk of Hongze Lake.