The Numerical Simulation Of QingLong River Flood Routing

With the unceasing development of the computer technology and the fluid numerical simulation technique, more and more water planning and designs are applied to the model simulation technique in order to carry on the design variable screening and the confirmation.The research is based on the design elements of the riverway of Black Dragon Lotus River, which establishes a suitable hydrodynamics numerical model for the regional project transformation and analyzes the drainage under different extremely hydrologic conditions by using numerical simulation techniques. This will provide the technical base for the management of project in the future.According to the different characteristics of flood-prevention of the riverway and dissemination of the flood wave, using unidimensional and two-dimensional numerical simulation hydrodynamics equation to establish the flood evolution numerical model and analyze the drainage with different frequencies of water in the river .This article includes the following main tasks:(1) Using the MIKE11 model, which was invented by Danish Water Conservation Research Institute (DHI), the unidimensional hydrodynamics model of riverway is established along the Black Dragon Lotus River. The reconstruction project involves 61 transformation cross sections,5 branch entrances and 4 pilot branch canals. The flood frequency boundary of the numerical simulation includes P=1%, P=2%, P=5% and P=10% and so on.(2) Using the MIKE21 model, which was invented by Danish Water Conservation Research Institute (DHI), constructing the numerical simulation model of the plane two-dimensional flood submergence process when the extreme flood inundates the dike along the partial sections of Black Dragon Lotus River. The research employs MIKE FLOOD module to carry on the simulation by using the unidimensional and two-dimensional model dynamic coupling. The boundary of the plane two-dimensional model can be endowed automatically by the MIKE FLOOD module in this mode, the flood spillage of the unidimensional riverway can be endowed to the specified boundary of the two-dimensional model.The parametric result of the research is basically identical with the parameter of the water planning and design data of Black Dragon Lotus River. At the same time, the research also verified that the Black Dragon Lotus River would be able to resist the flood which would be happen every ten years, then it draws the conclusion that the partial cross section of the bunding needs to be heightened and consolidated in the reconstruction. The research employed the unidimensional and two-dimensional model dynamic coupling to analyze the flood when it inundates the dike, which enhanced the efficiency of calculation, it is more suitable for the analysis of the flood submergence.