蓄水两坝间长系列水动力及泥沙淤积的研究

Long-Term Hydraulic-Dynamics and Sediment Accumulation Between Two Impounding Dams

对黄河上游龙羊峡至李家峡间的贵德-李家峡河段的蜿蜒河道进行了研究,为蓄水两坝间的通航和河床稳定性问题提供可行性分析依据.根据二维水流连续、运动方程、悬沙扩散方程和两相流底沙运动方程,采用加权集中质量剖分方法,建立了蓄水两坝间水动力、泥沙淤积数学模型.提出了泥沙交换和河床粗化计算模拟的物理图案,对长系列水动力和泥沙运动进行了模化处理.通过调试,验证了水尺水位和李家峡建坝前该河段4年的地形演变量.应用李家峡建坝后典型水文年长系列的组合资料,预报了河床经长期冲淤调整后达到基本平衡需要的时间.介绍了泥沙交换和河床粗化计算模拟的物理图案和长系列河床演变数学模型的研究方法.

The research of bend channel of reach Guide-Lijia Flume from Longyang Flume to Lijia Flume in upstream of the Yellow River is proceeded to present rules of feasibility analysis for navigation between the flumes and the riverbed stability. According to two-dimension flow continuity, momentum equations, suspended sand diffusion equations and two-phase flow bed sand motion equations, hydraulic-dynamics sediment accumulation mathematical model between two impounding dams was set up by adopting the methods of weighting and concentrating masses. The physical pattern of sediment exchange and bed coarsening simulation was put forward, and long-term data on hydraulic-dynamics and sediment motions were modeled. Through debugging the program, the water level of water foot in the river was verified, as well as the topographic evolution of the section of the river in 4 years before Lijla flume dam was built. Because the channel bed was adjusted by scouring and silting in long-term, the required period to reach basically equilibrium was predicted based on the typical and assemble hydrographic data in long series after the building of Lijia flume dam. The methods of simulating the physical patterns of sediment exchange and bed coarsening and establishing long series river-bed sediment accumulation mathematical model were also given.