Calculating Study On Flood Routing In Small Watershed Riverway

In recent years,small watershed floods in China have occurredoccasionally,which have caused significant impact to the local residents and social economy.Aiming for current status,the country invests heavily to initiate thetorrential floodwarning and forecastingproject.Compared with the large watershed,the flood forecasting of small watershed has the following characteristics,namely,short convergence time,complexlandform and severe impact of human activities on the underlying surface of watershed.They have brought great difficulties to the flood forecasting.In this paper,the Dongzhuang small watershed in Gu county of Shanxi province is taken as an example to study the flood forecasting model and method of small watershed.Firstly,the applicability of various flood routing methods in the watershed is compared and analyzed combined with the actual situation;NonlinearMuskingum methodand one one-dimensional de Saint-Venant system of equations are selected as hydraulics methods.Secondly,the mixed genetic algorithm is used to analyze the three parameters of K,x and n,and the established model is also validated.In the following,the MIKE11 HD model is used to calculate the flood routing of this watershed,and the influence of different roughness on the flood process is analyzed to determine the most suitable roughness value;Finally,the results of the two methods are compared,and the results show that MIKE11 model can better simulate the actual situation of the riverway,andhas better flood forecasting effect.