Numerical Simulation Research Of Medium And Small Rivers In Flood Analysis

Since time immemorial, flood disaster has been the most serious disaster in China, which has threatened the safety of civil lives and properties. The construction of flood control engineering systems in medium and small rivers can enhance the ability of flood regulation, and it is also one important means of flood risk management. Therefore, grasping the routing and influence of flood is necessary for scientific and reasonable flood control constructions in rivers. This paper adopted the Liaoning rational formula to calculate the design flood, then simulated flood routing in the watercourse by using MIKE11model. The established one-dimensional flood-routing model can simulate the degrees of damage to the dikes caused by different frequency of floods, while simulating the positions of the dangers dikes. And the two-dimensional flood model in inundated areas was established according to the elevation data, dike design code and land utilization condition. Then the flood and overflow were coupled for next work by using MIKE FLOOD. The above work is significant for scientific decision-making of flood control and risk avoiding. Contents of the paper are as follows:(1) Many medium and small rivers in China are lack of observed hydrological data, which makes it difficult to calculate the design flood and the precise flood routing. As a consequence it affects the accuracy of flood risk analysis. This article adopted the Liaoning rational formula to calculate the design flood, then simulated flood routing in the watercourse by using MIKE11model. Taking the Lower Fuzhou River as an example, the results showed that the method could demonstrate the process of flood routing dynamically with a high accuracy which had been proved by comparing the results with the data of historical floods. Therefore, the above work can be some degree of guide and reference of the flood risk analysis and flood management on the medium and small rivers.(2) Based on the one-dimensional flood-routing model, a two-dimensional hydrodynamic model was established and then the two were coupled to simulate overflow of the flood. In this paper, submerged area and flood duration were calculated and analyzed, which will be of certain assistance for disaster reduction, flood risk analysis and management of middle and small rivers.(3) According to the results, analysis on the crucial reaches vulnerable to flood inundation was made under exceeding standard flood disaster to inform flood risk condition, which can provide scientific basis for flood control and disaster reduction.