Study On Optimal Regulation Of Water And Sediment In Xiaolangdi Reservoir Considering Sediment Discharge And Power Generation Benefits

The regulation goals of large controlling reservoirs are multivariate,including comprehensive benefits of flood control,power generation,deposition reduction,irrigation,domestic water downstream,and ecological water demand for river health.Therefore,based on the basic goals such as reservoir flood control and power generation,this paper,with Xiaolangdi Reservoir as the study area,can be divided into two aspects.First,multi-objective decision-making method was used to establish the hydrodynamic model based on the theory of river dynamics and the reservoir optimal operation model based on the theory of dynamic programming.Secondly,considering the requirements of maintaining the middle-flood channel in the Lower Yellow River,a mathematical model for optimal regulation of flow and sediment of Xiaolangdi Reservoir was constructed by coupling the above two models.The main content is as follows.(1)The purpose and significance of the optimal regulation of reservoir flow and sediment are briefly introduced,and the research status at home and abroad on the targets selection of coordinative dispatch of water and sediment,the construction and solution of multi-objective model are summarized.(2)Introduces the basic information of Xiaolangdi Reservoir,and makes a simple analysis of the conditions of incoming water and sediment,regulation process,deposition of main stream and tributaries,and changing process of reservoir capacity.(3)A one-dimensional hydrodynamic model is established,including the key problems such as the calculation of the sediment carrying capacity,the density current in reservoir area and the relevant parameters in the riverbed deformation equation.The model reliability was validated by the contrast with measured data of water and sediment,and terrain data of Xiaolangdi Reservoir in 2016 flood season.(4)Based on the dynamic programming method,an optimal regulation model of Xiaolangdi Reservoir is established by integrating the minimum sedimentation amount and the maximum power generation benefit into the same optimal operation objective function.(5)Taking the real dispatching process of Xiaolangdi Reservoir in 2009 as an example,two optimal dispatching scheme which take the maximum power generating and the maximum comprehensive benefits of generated energy and sediment ejection in reservoir area were proposed.The calculation results show that compared with the real scheduling scheme,the power generation of the first plan increases by 20.7% and the sand delivery rate is 4.9%,while the second plan would increase power generation by 10% and sand delivery rate is 79%.(6)The research work of this paper was summarized and the future work was prospected.