The Multi-objective Scheduling Rules Research For Cascade Reservoirs In The Yellow River

The runoff in the Yellow River Basin is decreasing,while the demand for water is increasing.The current reservoir original scheduling rules can be no longer adapted to changes in the basin.Therefore,in view of the current situation of the Yellow River Basin with reduced runoff and increased water demand,it is particularly important to study the scheduling rules of cascade reservoirs that are more suitable for the new situation.In this paper,four large-scale reserving reservoirs with adjustable performance in the main stream of the Yellow River Basin,Longyangxia-Liujiaxia-Wanjiazhai-Xiaolangdi Cascade Reservoirs are used as research objects to analyze the response of water supply,power generation,sediment transport and ecological water use targets to cascade reservoirs,then the optimal scheduling model of cascade reservoirs is established and solved.The data mining method is used to study the scheduling rules according to the optimal scheduling results and compared with the traditional scheduling results,verifying the adaptability and superiority of the selected data mining method in multi-objective scheduling rules of cascade reservoirs.The results have guiding significance for the multi-objective actual scheduling of cascade reservoirs in the Yellow River Basin in the future changing environment.The main research contents and results of the thesis include the following parts:(1)Based on the natural runoff data of the main hydrological stations in the Yellow River Basin,the trend and the mutagenicity of the runoff are studied,and the water demand changes in the basins in 2020 and 2030 of the main stream in the Yellow River are analyzed.The results show that the runoff decreased,while the water demand is increasing.The average annual runoff of each station before and after the variability reduced by 10.49 billion m3 the most,and the comprehensive water demand of the basin increased by 2.43 billion m3.(2)Based on the long series of operational data of the Yellow River Basin and the water use characteristics of the four targets of water supply,sediment transport,power generation and ecology,the response laws of each target to the cascade reservoirs scheduling is analyzed by data statistics and the Range of Variability Approach(RVA)respectivly,to quantitativly describe the regulation and storage of cascade reservoirs.The results show that the cascade reservoirs have different effects on water supply,sediment transport,power generation and ecology.The scheduling of cascade reservoirs should integrate multiple factors,reflecting their comprehensive benefits.(3)According to the designed Longyangxia-Liujiaxia joint scheduling chart,the runoff sequence before and after the mutation is simulated and dispatched respectively,the results show that the scheduling chart is no longer suitable for the joint-operation of cascade reservoirs in the Yellow River Basin under environmental changes.An optimal scheduling model of cascade reservoirs with minimum water shortage as the target in the Yellow River Basin is established aimed to the runoff after variation and solved by particle swarm optimization(PSO).The rationality of the scheduling results is optimized from the long series operation process,comprehensive benefits and ecological pulse process analysis.(4)According to the optimization scheduling results of the cascade reservoirs in the Yellow River Basin and the rules for the formulation of scheduling rules,the Apriori algorithm of data mining is used to extract the reservoir scheduling rules,and the extracted scheduling rules are applied to the 2006?2010 series.By comparing the average annual power generation and water supply amount of each reservoir,the results of Apriori are better than the scheduling chart results.It proves the operability of the algorithm and the rationality of extracting the scheduling rules.