Key Techniques And Methods For Refined Simulation Of Urban Rainstorm

The high-precision flood simulation model is the core tool for solving urban flood warning and risk assessment.It is an emerging technology to improve the reliability of simulation based on the high-resolution topographic data to completely solve the two-dimensional shallow water equations.It is also a hot issue in academic research.In this paper,the two-dimensional hydrodynamic model is applied to the algorithm of urban storm water simulation.The adaptability of the model algorithm is tested by using several typical cases.The SFM method is used to provide high-precision topographic data for the model.Combined with a variety of parallel algorithm acceleration techniques,a parallel computing model for urban rainwater flooding in Harbin was established.The flood flooding simulation was carried out in Nangang District of Harbin,and good results were obtained.The main research contents and achievements of the thesis are as follows:(1)The algorithm for solving the two-dimensional shallow water equation is studied.The application conditions of the two-dimensional hydrodynamic model are tested by several classic cases,including the case of asymmetric dike-break model,the case of high and low slope rainfall model,and the dam break model of the building group etc.,the test shows that the two-dimensional hydrodynamic model established in the paper is suitable for urban rain flood process simulation.(2)The technical method of obtaining high-precision topographic data based on SFM is studied.The effects of various shooting measurement methods and parameter settings on the accuracy and measurement efficiency of terrain data are analyzed.The horizontal error is established.Centimeter-level DEM data.(3)The parallel computing technology of two-dimensional hydrodynamic model is studied,and a two-dimensional hydrodynamic parallel model based on message passing,shared memory and GPU graphics is constructed.The parallelization methods of the three models are expounded,and the adaptability,portability,operability and acceleration of the three parallel algorithms in the two-dimensional hydrodynamic model are compared and analyzed.(4)Taking the rainfall submergence in Nangang District of Harbin as an example,combined with high-precision topographic data and parallel algorithm technology,a parallel simulation model of rainwater refinement based on OpenMP and MPI was established.The actual rainfall data from June 2009 was simulated,obtained a good simulation effect.