Study On The Optimal Allocation Of Water Resources In Harbin Based On Uncertainty

Water resources are the core natural resources that human society depends on for survival and development.With the joint promotion of population growth and urbanization,the world's water demand has increased dramatically,and the global water crisis has become increasingly severe.In recent years,the accelerated urbanization process in China has led to a significant increase in urban water demand,coupled with uneven spatial and temporal distribution of water resources and backward management of water resources,which has intensified the conflict between water supply and demand and the risk of water resources security.Therefore,it is particularly important to optimize the allocation of water resources to improve the efficiency of water resources utilization and promote the balance of water supply and demand based on the principle of urban green sustainable development.It is also of far-reaching significance to promote the coordinated and sustainable development of urban society,economy and ecological environment.Previous studies did not fully consider the uncertainties and dynamic complexity of the urban water resources system,which makes traditional models have limitations in practical applications.This study considers multiple uncertainties in water resources management and constructs new dynamic mathematical models for long-term water resources planning,in order to provide managers with real-time and reasonable optimal water distribution plans in different planning periods.Firstly,based on the traditional Inexact two-stage stochastic programming(ITSP)model,taking into account the information uncertainty of the urban rainfall-runoff,using linear partial information(LPI)theory analysis the flow probability distribution,then establishing an Interval Two-stage Partial Information Programming Model(ITPM);Secondly,considering the time dynamics of the management process in the long-term planning of water resources,this study promoted an inexact multi-stage interval-parameter partial information programming model(IMIPM);Finally,the newly established models are applied to the water resource management system in Harbin,and multiple water sources(surface water and groundwater)are supplied to multiple water demand sectors(domestic water user,industrial water user,agricultural water user and ecological water user)in different planning periods Eventually,the goals of harmonious and sustainable society,economic development and ecological environment protection will be achieved.The results show that:(1)Compared with the traditional water resource management model,the ITPM model can effectively deal with random problems and interval problems under uncertain conditions.Through this model,the analysis of water resources allocation in Harbin City has obtained four flow level distribution scenarios,which overcomes the impact of uncertain factors such as rainfall-runoff on the benefits of the water distribution system can effectively balance the economic benefits and the risk of water shortage penalties.(2)The IMIPM obtained by adding the MSP method on the basis of the ITPM model can simultaneously handle the uncertainty of rainfallrunoff information,the dynamics of the time series in the long-term planning of water resources,and other uncertainties expressed by joint probability and interval values.According to the water resources and climate characteristics of Harbin,the planning time period is divided into the half year of summer and half year of winter,and the optimal solution for each time period is obtained through the model,so as to obtain the optimal allocation strategy for the entire planning period.(3)Under both models,the water distribution trend in Harbin is the same.Both models should ensure that the pre-requisite water demand is met.After satisfying the users' basic water use,the remaining water will be allocated to municipal,industrial,and ecological and agricultural users in accordance with the water distribution benefit and the maximum water consumption constraints.In addition,according to the results of the two models,managers can predict the choice of positive or conservative water distribution schemes based on the probability of occurrence of different incoming water levels.The two models increase the flexibility of decision-making.In short,the coupling of interval two-stage stochastic programming,multi-stage stochastic programming,and linear partial information theory for the optimization of urban water resources allocation is an improvement and development of traditional models.The obtained optimized allocation plan is given in the form of intervals,which more truly reflects the actual urban water resources management situation,and provides managers with decision-making space and technical support to promote the green sustainable development of the economic society,resources and ecological environment.