Optimal Flood Control Operation Model And Its Application In The Leading Multireservoir System In Upper Yangtze River

Respect to flood problem of Chongqing City, t his paper researches on flood control model and its application to 5 key reservoirs on Upper Reach of Yangtze River, include Xiluodu reservoir, Xiangjiaba reservoir, Zipingpu reservoir, Pubugou reservoir and Tingzikou reservoir. According to the scale of the flood, this paper establishes three different models of flood control and analyses each model’s effect and applicability.(1)The reservoir operation theories, methods and development process are reviewed. The study analyses the tasks and scheduling rules of the five reservoirs. Depending on the inflow of each reaches, four flood typical years are selected. Design flood process is generated by using the method of multiple proportion amplifying.(2)For small or medium flood, two different strategies are applied. The first is to maximize the extra flood control capacity of reservoirs. According to the strategy, the study establishes a linear programming model of reservoirs’ joint optimal operation, and using C# programming language with linear programming tool to solve this model. This paper analyses the influence of the weight of the remaining flood control capacity, introduces a calculation method of the weight. Compare the result of applying two groups of weight, it shows the importance of the weight of the remaining flood control capacity. The second strategy is to maximum safety degree of flood control system. Firstly, this paper describes the disadvantage of general calculation method of safety degree and proposes a piecewise linear calculation method of safety degree, then it establishes reservoirs’ joint optimal operation model with the aim of maximizing piecewise linear safety degree and uses mixed integer linear programming to solve it. Compare optimal results between calculation method of general safety degree and piecewise linear safety degree, piecewise linear safety degree shows its superiority.(3)For the great flood, apply the strategy of minimizing flood peak. This paper establishes reservoirs’ joint optimal operation model with the above strategy, introduces a method of generating suitable initial solution and solves the model by POA algorithm. Result shows the different effect of each typical year and the reason of the difference is analyzed from the perspective of the flood composition.