Research On Flood Forecasting Scheme Of Dagujiahe Basin

The flood disaster is one of the natural disasters that threaten to human survival. In the long struggle against the flood disaster, people accumulated a lot of measures and technical means, the flood forecasting is considered to be the most effective non-structural measures for flood control, it has played an important role in the science dispatch and in reducing the loss of flood disaster. The impact of human activities and the restrictions of hydrological data make it more difficult to get higher accuracy flood forecasting results of some river basin. This paper taking Dagujia River Basin as the research background, firstly, analyze the composition characteristics of flood, divide the flood forecasting unit reasonable; secondly, research the flood forecast scheme of each unit by using different methods; the last, based on the existing problems of the forecast scheme and the focused forecasting factors of flood control operation, to explore the modified method of flood peak forecast. Main contents and conclusions of this study are as follows.(1) Data analysis and the basin prediction unit division. Analyze the flood composition of Dagujia river, divide its forecast unit into two forecast units, the forecast unit of upper Fushan hydrologic station in Waijiahe river and the forecast unit of upper Menlou reservoir in Neijiahe, According to the hydrological characteristics of Dagujia river basin and the characteristics of underlying surface,select the DHF model as the basic model for flood forecasting scheme, The model parameters are calibrated by using Particle Swarm Optimization and Manual trial and error method.(2) Research on the flood forecasting scheme of the basin of upper Fushan hydrologic station. Due to the numbers of rubber dam and the flap gate project that built since 1990 between the Xihuili precipitation station and Fushan hydrologic station in the Waijiahe river course, and lack of dam operation data, so it’s unable to recover data. So,the research of forecasting scheme of upper Fushan hydrologic station is using the 16 floods data before 1990,There are qualified 15 floods simulations according to< Standard for hydrological information and hydrological forecasting GB/T 22482-2008>, The qualified rate is 93.8%.Using the floods forecasting scheme to stimulate the 9 floods after 1990,the simulation effect of the small flood is poor, while the big flood is better(the influence of gate dam on big flood is less), The application results show that, the upper Fushan hydrologic station floods forecasting scheme that made before 1990 can guide the real time flood dispatching decision of Dagujia basin。(3) Menlou reservoir flood forecast plan and study on the modification of flood. First select the 20 floods of data to research the Menlou reservoir flood forecast scheme without considering the influence of water conservancy project and human activities, then based on the location of the basin conservancy project and the characteristic of the layout of hydrometric stations and the actual needs of the Menlou reservoir flood dispatching decision, adopt the correct technology of flood peak by synthetic unit hydrograph and fuzzy inference model, correction result shows that the qualified rate of flood peak rose to 85%from 65%that before correct, and it can be used in the actual flood forecast operation.Finally, summarize the main research contents and results, points out the inadequacies and further prospects.