Research On Flood Wave Propagation In The Three Gorges Reservoir Area Based On MIKE11

Flood and waterlogging disasters are one of the most serious natural disasters faced by mankind.As the longest river in China,the Yangtze River Basin has frequent heavy rainstorms and extensive flood and waterlogging disasters.The construction of the Three Gorges Project plays a huge role in flood control.However,after the completion of the reservoir,the dam will produce drowning water,the dry tributary water level will rise,the width of the water surface will increase,and the flood propagation pattern will change significantly within the reservoir area.Therefore,taking the Three Gorges Project as the background to study the flood propagation law in the reservoir area under the conditions of reservoir drowning,it has important practical significance for making the reservoir operation plan,guiding the engineering practice,and sand adjustment of the reservoir.Based on the topographical data of the Three Gorges Reservoir since the Three Gorges Reservoir was built and the measured hydrological data over the years,the method of numerical simulation and analysis of one-dimensional hydrodynamic model based on MIKE software was used to simulate and calculate the reservoir area under different incoming water and different reservoir water levels.The flow velocity,wave velocity,wave velocity,and time of flood wave propagation were analyzed.The deformation law of flood wave in the presence or absence of inflow in the region was analyzed,as well as the propagation law and motion characteristics of the flood wave.The research results show that:(1)The flood wave propagation time decreased with the increase of the Three Gorges Reservoir water level,and increased with the increase of the flood peak discharge of Zhutuo.(2)Under the condition of no interval inflow,the flood waves undergo a candid deformation during the propagation process.Considering the regional inflow and the relatively large inflow,the peak discharge of the downstream section is significantly higher than the peak discharge of the upstream section,and the volume of the flood wave becomes larger.The inflow of the interval has a significant impact on the peak of the dam site.(3)The motion characteristics of the flood waves in the Zhutuo~Cuntan section of the Three Gorges reservoir area are in line with the characteristics of the motion wave and belong to the flat water area.The propagation characteristics of the flood wave are switched between the transitional area and the flat water area from the Cuntan to the Qingxichang.And the greater the flood peak flow and the lower the reservoir water level,the more it tends to the flat water area.The stream from Qingxichang to Wanxian meets the flood propagation characteristics of the transitional area;the motion characteristics of flood waves from the Wanxian to the dam interchange in the transitional area and the impoundment area.(4)When the peak flow of inflow water increases and the water level of the reservoir decreases,the length of the river segment that conforms to the propagation characteristics of the motion wave flood extends,and the length of the river segment that meets the propagation characteristics of the flood wave of the power wave decreases.