崇明岛4座水闸外移工程水沙数学模型

Numerical model on four sluices outward relocation project of Chongming Island

受地理位置、水文气象、地形地貌等因素影响,崇明岛洪涝灾害频发,特别是中北部排水出口缺少且规模偏小,不满足暴雨期间排涝的要求。为科学评估崇明岛堡镇港北闸、四滧港北闸、六滧港北闸和八滧港北闸4座水闸外移工程对本区域水沙动力条件的影响,开展水沙数学模型研究工作。结合近年来该区域实测水文泥沙资料,分析该河段水文、泥沙特性及河势演变特征,研究工程河段水沙运动特性。建立工程河段三维水沙盐数学模型,在模型率定及验证的基础上,利用该模型对北支下段崇明岛北沿防汛除涝工程平面方案的实施效果进行模拟计算。结果表明:工程实施后对周边水域的水流条件以及周边水域及北支水道主槽的河床演变基本无影响。研究成果可为工程建设提供技术支撑。

Affected by the geographical location,hydrometeorology,topography and geomorphology,flood disasters occur frequently in Chongming Island of Shanghai.Especially,due to the lack of drainage outlets in the north and central part of the island,it cannot meet the requirements of drainage during the rainstorm.To scientifically evaluate the influence of the four sluices outward relocation project of Chongming Island on the dynamic conditions of water and sediment in this area,we carry out numerical modeling of hydrodynamics and morphology.Combined with the measured hydrological and sediment data in this area in recent years,we analyze the characteristics of hydrology,sediment,and river regime evolution in this reach,and study the characteristics of water and sediment movement in the engineering reach.Meanwhile,we establish a three-dimensional numerical model of water,and sediment in the engineering reach to simulate and calculate the implementation effect of the plane scheme of flood control and de-watering project along the north side of Chongming Island in the lower section of the North Branch based on model calibration and verification.The results show that the implementation of the project has little influence on the flow condition of the surrounding water areas and the bed evolution of the surrounding water area and the North Branch channel.This study provides technical support for engineering construction.