Research And Application Of Numerical Simulation Of Urban Rainfall Flood

Nowadays,due to the fast development of the urban economy,the harmful effect caused by the urban rain flood becomes more and more serious.When the strong rainfall occurred in the city,the river network(pipe network)due to insufficient drainage capacity,will usually cause waterlogging in the city,it has a negative effects on social prosperity,stability and people's safety.Urban flood disaster is one of the main factors that restrict the development of urban economy,how to prevent and control the risk of urban flood disaster and reduce disaster losses has aroused wide attention of all society.As the key technology of non-engineering measure of flood prevention,the role of urban rainfall flood numerical simulation technology in flood control and drainage is becoming more and more prominent,it is of great significance to carry out the research on the numerical simulation of urban rainfall flood.The first part of this paper introduces the influence of urbanization on urban hydrological environment,analyzes the causes of urban flood disaster,reviews and summarizes the research status,development trend and technical difficulties of domestic and international urban rainfall flood numerical simulation technology,explains the necessity of carrying out the research on the numerical simulation technology of urban rainfall flood and the main contents of this paper.The second part of the paper use Pressman slit hypothesis and the one-dimensional Saint-Venant equations to establish one-dimensional free surface pressurized flows model of city rainfall flood;Create the hydrodynamic model based on the solution of the 2D ground shallow water equations;Finally,use the experimental formula to establish the coupling model of one-dimensional free surface pressurized flows model and hydrodynamic model of two-dimensional ground surface.After the model is established,use several examples to verify the one-dimensional model,the two-dimensional model and the two-dimensional coupling model.Finally,the accuracy and reliability of the model has been verified by the result of examples,which shows that the model can be applied to the numerical simulation of urban rainfall and flood.On the basis of deep understanding the terrain,climate and rainfall conditions of the Beltway in Chengdu,conduct the river designed flood process and regional design storm,and then use these boundary conditions to model the regional urban rain flood.At the end of this paper,summarizes the full text and describes the future research direction.