三峡水库不同水位运行下大宁河水动力过程模拟

三峡大坝的建成运行对库区支流水动力过程具有重要影响。以三峡库区支流大宁河为例,基于Delft3D模型,建立了大宁河大昌到长江口段平面二维水动力模型,并对三峡水库高水位和低水位运行条件下大宁河的水动力特征进行模拟计算,得到大宁河模拟区段水流流场的沿河分布。模拟结果表明:不管是三峡水库低水位或高水位运行,大宁河整体流速缓慢,均低于0.04 m/s;河流库湾区低水位时流速低于0.01 m/s,高水位时低于0.001 m/s,呈现明显的"湖相"特征,水体自净能力极大地削弱,易发"水华",影响大宁河水质安全。研究结果可为三峡库区支流的区域化管理提供决策参考。

Modeling the hydrodynamics of Daning River under different working condition of Three Gorges Reservoir based on Delft3D

The operation and construction of the Three Gorges Reservoir has an important influence on the hydrodynamic force of the tributaries of the reservoir. In this paper, Daning tributary of the Three Gorges Reservoir was used as an example, based on the Delft3D model, to establish a two-dimensional hydrodynamic model of Dachang of Daning River to Changjiang Estuary. The hydrodynamic characteristics of the Daning River under high water level and low water level operation of the Three Gorges Reservoir were simulated, and the distribution of water flow in the simulation section of Daning River was obtained. The simulation results show that the overall flow velocity of Daning River area is slow, which is less than 0.04 m/s when the Three Gorges Reservoir runs in high and low water level. The flow velocity of backwater regions of Daning River is less than 0.01 m / s at low water level and less than 0.001 m / s at high water level, which is obviously characterized by lacustrine facies, The water self-purification ability is greatly weakened, which is prone to cause water bloom and affect the water quality of Daning river. Our results can provide support information for the management of the tributaries of the Three Gorges Reservoir area.