Research On Comprehensive Power Generation Risk And Transmission Law Of Reservoir With Uncertain Runoff Of Xijiang River

The Xijiang River is part of the Pearl River Basin.The special rainfall characteristics in the Xijiang River Basin leads to the coupling and transmission of the risk of inter-reservoir comprehensive power generation due to the objective uncertainty of the reservoir operation scheme in the basin.Key reservoirs are interconnected,joint dispatch,etc.The risks between reservoirs are mutually transferable,and there will be quantitative and qualitative changes in the transmission,showing a variety of transfer methods.In order to solve the problems in risk transmission,and overcome the risk dispatch problem of reservoir groups that conform to the random characteristics of the river basin,obtain operational dispatch rules that are more in line with the risk management of river basin reservoirs,improve the scientificity and rationality of reservoir dispatch,and fill the gaps in reservoir dispatch research.It is necessary to study the uncertainty risk of reservoir operation in the river basin.The study launches research on four key reservoirs,takes the uncertainty of runoff into consideration in the comprehensive power generation model of reservoir dispatching,analyzes the impact of uncertainty of runoff on the risk evaluation index of each power generation of the reservoir,and compares the different frequency of water inflow.Incoming water is scaled proportionally according to the actual water distribution process in the past years to present the uncertainty of runoff.The future water process is input into the comprehensive power generation model of reservoir dispatching,revealing the law of the influence of runoff uncertainty on the comprehensive power generation risk of the reservoir;For the first time,a research method that can identify,evaluate,and transmit risks is proposed and each reservoir group is evaluated Comprehensive power generation risk on the time and space scale,analyze the transmission law of risk between reservoir groups,clarify the risk transmission path,direction and intensity,and reveal the transmission law of comprehensive power generation risk of key reservoirs.The main conclusions are as follows:(1)With the decrease in the total amount of water in the years,the power generation risk evaluation index and the comprehensive power generation risk are both on the rise.Faced with different water supply schemes in dry years,the comprehensive power generation risk of Longtan Reservoir is 0.37～1.00,and the comprehensive power generation risk of Yantan Reservoir is 0.23～1.00,and the range of variation is the largest,that is,the comprehensive power generation risk in dry years is most easily affected by the inflow of water during the year;(2)The comprehensive power generation risk in the upstream reservoir is bigger than the downstream comprehensive power generation risk and the water situation in 2008 was the best among several water supply plans in the dry years;(3)The comprehensive power generation risk is transmitted along the river system between the reservoirs,and will not be transmitted across the reservoirs.The transmission between Tianshengqiao Level 1,Longtan and Yantan is of attenuation type,and the attenuation intensity of Longtan Reservoir to Yantan Reservoir is greater than that of Tianshengqiao Level 1 Reservoir to Longtan Reservoir.(4)The risk transfer value of Tianshengqiao Level 1 Reservoir to Longtan Reservoir and the risk transfer value of Longtan Reservoir to Yantan Reservoir show a consistent increasing or decreasing trend.The intensity of risk transmission is as follows:more water,less transmission,and less water,more transmission.In the representative years of high water years(2013),normal water years(2007),and dry years(2015),the risk values transmitted from Tianshengqiao Level 1 Reservoir to Longtan Reservoir are 0.73,0.09 and 0.00,respectively.Longtan Reservoir The risks transmitted by Yantan Reservoir are 0.08,0.09 and 0.00 respectively.All in all,this study provides new ideas for the study of the impact of reservoir runoff uncertainty on comprehensive power generation risks,and provides scientific theoretical guidance for the establishment of risk dispatch models for optimal management and control of river basin water resources in water resources management.