Research On Stage Limited Water Levels And Dynamic Operation For Reservoir Flood-control

With the increasing growth of population and the rapid development of economy&society, water requirement will increase and water resource shortages will be worsen. The appropriate use of flood resources will become an important way of solving regional water resource shortages. Flood resource utilization is the important measure and realistic choice to achieve sustainable strategic aims of water resources development. With scientific and technological progress, reservoirs play the key role of floodwater resources utlization, under the premise of not increase the flood risk. Transforming part of the flood to available water resources has important practical significance to relieve the basin water crisis.Reservoir flood control level is an important indicator of reservoir flood control operation. It is directly related to a reasonable solution to the contradiction between the objectives of reservoir flood control and profiting from the reservoir real-time scheduling process. If flood limit water level is higher, it is conducive to profiting from available water resources; on the contrary, it is beneficial to flood control. Therefore, it is necessary to study the flood limit water level under the premise of guaranteeing the safety of reservoirs during the flood season. Firstly, it is discussed for the definition and description of the watershed flood season, common methods of flood season dividing of reservoir. And this paper concentrates on study on the applications of fuzzy set analysis method and the fractal method in the flood season staging.Secondly, the computing method of reservoir flood control level is detailed, including the flood limit water level stage control and real-time dynamic control. After compared the advantages and disadvantages of the two methods and the applicability of them, the flood limit water level stage control is employed for the reservoir of case study. The risks and benefits form flood limit water level adjustment are analysied, including the risk of overtopping and dam failure risk. Also their calculation procedures and effective identification and analysis methods are proposed. The benefitness from floodwater resources utlization is analysised, based on the main function of the researched reservoir.Finally, the fuzzy analysis method is used for studying flood limit water level according to the aforementioned method and its principles. Take Gaotang Reservoir, in Jiangsu for example, its flood season stage and the flood control level is derived, and the overtoppingrisk and water supply benefits are analyzed. From research results, it is concluded that if raising the water level from34.5m to35.5m, it will increase the water supply benefitness of8.9575million yuan.