Research Of Optimal Allocation Of Water Resources Based On Uncertainty In Wuwei City

Water resources are important strategic resources for economic development and social progress.However,the shortage of water resources has become increasingly severe under the influence of various factors such as climate change and human activities,and optimizing the allocation of water resources is one of the main ways to alleviate the shortage of water resources.At the same time,the complexity of the water resource system leads to uncertainty in parameters such as society,economy,supply and demand of water in the process of water resource allocation.Therefore,it is of great significance for achieving sustainable regional development by studying methods and models for optimizing the allocation of water resources under uncertain conditions.This paper takes Wuwei City,Shiyang River Basin as the research district and establishes the water resources carrying capacity model for evaluation.Then,the complex relationships between multiple processes,levels,elements,and objectives in the water resource allocation process of Wuwei City were analyzed under the consideration of the uncertain characteristics in the process of water resource allocation,and water resource optimization allocation models were constructed under different situations.The main contents and conclusions of this paper are as follows:(1)Analysis of water resource carrying capacity.Water resource carrying capacity evaluation index system is constructed,which includes 4 subsystems and 14 classification indicators based on the actual situation of Wuwei City.According to the statistical data from2013 to 2020 in Wuwei City,indicators are selected and their weights were determined using a combination of subjective and objective methods.The improved TOPSIS model is used to evaluate the water resource carrying capacity,and the obstacle degree model is used to analyze the main factors restricting the water resource carrying capacity.The results indicate that the water resource carrying capacity of Wuwei City showed a fluctuating upward trend from 2013to 2020,but the overall carrying capacity level was relatively low.Indicators such as water production modulus and per capita water resources are the main obstacle factors,and the water resources subsystem is the primary subsystem that restricts the carrying capacity of water resources.In addition,there are also problems such as unreasonable industrial structure and low water resource utilization efficiency in Wuwei City.(2)An interval double-sided stochastic chance constrained programming model is established.Maximizing economic benefits,minimizing water scarcity,and minimizing COD emissions are selected as the objective functions.Box-Muller method is used to simulate runoff,reflecting the random characteristics of the input parameters of the model.Characterize the efficiency coefficient and water demand of the water department as discrete interval forms,and select different violation probabilities to introduce into the model.Allocate water resources for the water department of the water source area,and obtain optimal allocation results under different risk levels.The results indicate that the economic benefits and available water increase with the increase of violation probability;The optimization results have increased the proportion of industrial and ecological water use,reduced the proportion of agricultural water use,and adjusted the industrial structure for better development.The economic benefits have increased by 8.01%compared to the current year,the water shortage has gradually decreased,and the COD emissions have decreased by 17.62%.(3)A fuzzy max-min bi-level multi-objective interval programming model was established.The model consists of two levels,taking both water distribution fairness and economic benefits into account,and the objective of upper level is Gini coefficient and the objective of lower level is agricultural benefits of each district.The fuzzy max-min programming method is used to solve the model,water resource allocation was carried out for different water sectors in different regions,and optimal allocation results were obtained under different representative hydrological years.The results indicate that the amount of water resources remains one of the important factors restricting the development of Wuwei City.The agricultural sector has the highest proportion of water use,and the ecological water distribution in Minqin is much higher compared with other regions.The fairness of water distribution in the industrial sector between different districts is poor.The developed model can not only solve water resource conflicts at the same level or different levels,but also deal with multiple uncertainties in the process of water resource allocation.(4)A fuzzy nonlinear multi-objective programming model is established.Aiming at the maximum economic benefit and water productivity,the nonlinear water production function of the whole crop growth period was selected,and the weights were obtained by AHP method.Then,improved particle swarm optimization algorithm was used to solve the model.Expressing supply and demand water data in a fuzzy form and introducing fuzzy set theory is introduced to the paper.Optimizing the allocation of agricultural water resources in Minqin under differentα-cut levels,and obtain an irrigation water optimization scheme.The results indicate that the maximum agricultural economic benefit is[6.13,9.02]×10~8 yuan,the multi-objective model takes both economy and efficiency into account,and can balance the competition of water resources between different objectives.Agricultural crops are sensitive to water.In the case of water scarcity,the model prioritizes meeting food security needs and ensuring normal production activities;when water resources are sufficient,priority should be given to crops with higher unit added value for water resources allocation.