童家湖蓄滞洪区洪水演进数值模型研究

为更加科学、有效地运用童家湖蓄滞洪区,降低洪涝灾害损失,以二维非恒定流基本控制方程为理论基础,根据童家湖蓄滞洪区1:5000实测地形资料,基于非结构三角形网格,采用有限体积算法建立了蓄滞洪区洪水演进数学模型。依据所建立的模型,模拟分析了设计分洪条件下分蓄洪区内洪水演进过程,还选取了蓄滞洪区内若干有重要代表意义部位,在其模拟计算的水位增长及流速变化过程基础上,进一步分析了分洪不同时段蓄洪区各区域的洪水淹没趋势。模拟结果显示:童家湖分洪开始约2 h,分洪洪量主要在分洪口附近填洼;分洪前20 h洪量主要集中在蓄滞洪区南部;20 h后,北部洼地填满后蓄滞洪区内联通,各处水位同步涨落。模型可以较完整地反映童家湖蓄滞洪区内洪水演进过程,研究成果可为童家湖蓄滞洪区分洪准备、撤离转移等工作提供决策参考。

Study on numerical simulation for flood routing of Tongjia Lake flood detention area

In order to make more scientific and effective use of Tongjia Lake flood detention area and reduce the loss of flood and waterlogging disaster, we established a flood routing mathematical model for the detention area based on the basic two-dimensional unsteady flow equations, unstructured triangular grid and 1〖DK(〗∶〖DK)〗5000 measured topographic data of the area by finite volume method. Based on the established model, the flood routing process for the detention area under designed flood diversion conditions are analyzed. In addition, the water level and velocity variation process and flooding trend of several typical sites in the detention area are simulated. The results show that in the beginning 2 hours, the flood was mainly detained near the flood diversion inlet; in the first 20 hours, the flood was mainly concentrated in the southern part of the flood detention area; 20 hours later, the water levels fluctuated synchronously in detention area after the flood filling up the lower floodplain in the northern part of the detention basin. The model can reflect the flooding process of Tongjia Lake flood detention area completely. Furthermore, the relevant laws can provide decision-making reference for flood diversion preparation, evacuation in the diversion area.