Risk Operation And Assessment Of Reservoir Group In Inter-Basin Water Transfer Project

The reservoir scheduling of inter-basin water transfer projects can effectively alleviate the uneven distribution of water resources in time and space,but the risk control problem of water transfer caused by the uncertainty of incoming water demand has not been solved yet.Therefore,this paper focuses on the scientific issue of constructing a risk regulatory system for an interbasin water transfer project,intends to take the inter-basin water transfer project from Hanjiang to Weihe River as the research object,and establishes a risk definition,risk operation,risk assessment,risk prevention and control system for the inter-basin water transfer project.Firstly,the runoff prediction model of EEMD-LSTM is constructed,the applicability and superiority of the runoff simulation of the model are verified,and the evolution law of future runoff is analyzed.Secondly,the disaster risk theory is applied to define water transfer risk and a reservoir group risk operation model with the minimum average water transfer risk is established.The spatiotemporal transmission law of water transfer risk and the influence law of risk factors on risk degree is elucidated.Thirdly,a joint distribution function of water transfer risk is constructed using the Copula function,revealing the distribution law of risk probability.An improved risk matrix method is proposed to classify risk levels,revealing the encounter law of water transfer risk levels between the water source area and water receiving area;Finally,an risk evaluation index system for the water transfer from the Jialingjiang to Hanjiang River.A combined weighting method is used to construct an evaluation model based on the ideal solution method to recommend the suitable water transfer flow,and the prevention and control measures to deal with the risk of water transfer are put forward.The research results have certain theoretical significance for the construction of reservoir risk operation models and have important application value for water supply safety guarantee and water transfer risk control of inter-basin water transfer projects.(1)A runoff decomposition rolling prediction model based on EEMD-LSTM is established and applied to the future runoff prediction of Huangjinxia,Sanhekou Reservoir and Lueyang section.The simulation accuracy of the prediction model is evaluated by RMSE,NSE and MAE simulation evaluation indexes,and the applicability of the EEMD-LSTM model was verified.Through the analysis of the trend and variability of the runoff,the possible period of water transfer risk is estimated.(2)The reservoir group risk operation model is established with the minimum average water transfer risk in the water source area as the objective.The genetic algorithm is used to solve the model.The risk operation model can optimize the time distribution of water transfer risk and effectively reduce the risk of system water transfer.The transfer law of water transfer risk is analyzed.With the decrease in water inflow,the risk of water transfer increases time by time and the risk of water transfer from the water source area to the water receiving area decreases.The influence law of risk factors on risk degree is explored and the quantitative transformation formula is deduced.The risk source and hazard-bearing body are reduced,the corresponding relationship between risk factors and risk degree is enhanced,and the risk degree is reduced.(3)The Copula function is used to construct a joint probability distribution function for risk.The distribution pattern of risk probability is revealed,with an increase in risk probability under the same risk degree and a decrease in risk degree under the same probability.Based on risk degree and risk probability,an improved risk matrix method is used to classify risk levels and apply them to water transfer risk between the water source area and receiving area.The probability of encountering the risk level between the water source area and the water receiving area is calculated.The probability of risk degradation transmission is relatively high,but as the risk level increases,the probability of risk degradation transmission from the source area to the receiving area gradually decreased.(4)Considering the indexes of water transfer,ecology and risk,the TOPSIS evaluation model is constructed based on the combination weighting method of analytic hierarchy process and entropy weight method.The most suitable water transfer flow from Jialinjiang to Hanjiang is 40m3/s,which meets the requirements of water transfer in engineering planning.Effective risk prevention and control measures have been proposed to address the extreme risk situations encountered in the water transfer project from Hanjiang to Weihe River.This has important practical significance for formulating emergency dispatch plans,reducing water transfer risks,and ensuring the safety of inter-basin water transfer.