Research On Flood Control Forecasting And Operation For Reservoir Group Of Qiantang River Basin

The flood control system composed by reservoir group and rivers is the most typical flood control system of river basin, the paper takes Qiantang River basin as an example, the technique for forecast and operation of reservoir group is studed. the nature and significance of non-engineering measures of flood control is summarized in the paper; it is summed up that the current status and development of hydrology models and the theory and methods of river basin flood control operation; and frontier and hot points of the river basin flood control system real-time joint operation research are pointed out.The paper analyzed flood characteristics, spatial and temporal distribution law, distribution condition of engineering and engineering characteristics. In order to improve flexibility of forecasting and operation models, as well as adaptability for locality of Qiantang River flood, the flood control sysem of Qiantang River basin is decomposed into multi-subsystem made up of single reservoir and reservoir group, so we can use partition compensation method for joint operation of reservoir group.According to decomposition result of flood control system and the requirement of reservoirs compensation operation, as well as climate and underlying surface conditions of Qiantang River basin., the paper chose Xin'anjiang Model to forecast real-time flood of river basin and reservoirs, flood forecast parameters are determined from six large reservoirs and five sub-river basin, and carried on simulation and examination for the forecast model.The paper put forward reservoir storage allocation model for the parallel reservoir group, it is basically consistent that reservoir control area and flow travel time of each reservoir arriving a common flood control cross section. The model can show important difference of different flood control point, it realized free combination for compensation mode and peak reduction mode. Meanwhile, the multi-level interactive model for flood control operation of reservoir group is put forward in the paper, the model can set up different target function for each reservoir, can respond the difference of each reservoir flood control mission, and indirectly embody limited contact of the reservoirs.The paper analyzed the difference of design and management for limited water level during flood season, as well as the feasibility to dynamic control of limited water level during flood season. Two kinds of real-time control method for the top control water level are put forward including Gradual Relaxation method and Follow-up Rain Reserving method. In order to reduce gate operation frequency and over impoundment risk, the paper put forward dynamic control technique of limited water level during flood season, it confirms overtake storage capacity through pre-discharge capacity of benefit promotion and flood control.