Runoff Prediction Based On The Conceptual Hydrological Model Study

The accurate and promp, medimun and long-term inflow forecast of reservoir is very important for instructing reservoir's flood protection, optimal dispatch, and raising its control utilization level. This study is supported by the research project of "The joint optimal dispatch of Luhun reservoir and its hydropower station". To meet the needs of the multi-purpose reservoir's optimal dispatch, the related problems, such as the runoff forecasting models, methods and application and so on, are studied systematically in this dissertation. The main research points are summarized as follows:(1) The principle problems and research tendency of the watershed hydrology model are expounded on the basis of summarizing the exsiting research results of the domestic and overseas, which are depending on consulting literature systematically. And the main research content in this dissertation is confirmed.(2) The Xinanjiang model and BUCKET series models are introduced. At the same time, the BUCKET models considered snowmelt runoff are built. The different models are applied in Luanchuan watershed, which is located in upstream of Yihe river basin. The principles, structures and application efficiency of these models are compared and analyzed. The foundation basis is supplied for choosing the model of inflow forecast in Luhun reservoir.(3) Aimed at the situation of Lunhun Reservior, the SL-BUCKET model and Nash model are used to simulate runoff generation and watershed routing respectively for inflow forecast of Luhun Reservior. The Kalman filter method is adopted to improve the model efficiency on the basis of analyzing the simulated and forecasting results, and the results are compared with the original forecast model results. The new approach is supplied for runoff forecast of Luhun reservoir.(4) The statistical property and distribution type of the hydrological forecasting error are fitted and verified adopting flood-forecasting results of Luhun reservoir. The uncertainty influence factors, such as flood-forecast error, flood-sellection and flood-operation delay, are simulated by using Monte-Carlo simulation technology. Then the risk, which is caused by utilizing Luhun reservoir's floodwater resources by stage, is estimated. Finally, the optimal reservoir flood control limiting water levels by stage are supplied for Luhun reservoir.(5) Combining the theory and the application research results, the conclusion and the questions needed to be studied deeply are presented.