Study On Carrying Capacity And Optimal Allocation Of Agricultural Water Resources In Yanghe River Basin

With the development of society and the influence of climate,the shortage of water resources is becoming more and more serious.At the same time,the unreasonable development and utilization of water resources cause the deterioration of water environment.In order to solve the problems of water shortage and water environment,it is necessary to study the carrying capacity and optimal allocation of agricultural water resources.Based on the comprehensive analysis of domestic and foreign research theories and methods of water resources carrying capacity and optimal allocation,starting from the current situation of Yanghe River Basin,this paper uses the fuzzy comprehensive evaluation method to carry out the evaluation of agricultural water resources carrying capacity of Yanghe River Basin,and constructs the optimal allocation model of agricultural water resources based on the water quality reaching the standard.The main research contents and conclusions are as follows.1.In order to select the evaluation indexes reasonably,aiming at the problem of losing important information when the factor load values of the indexes are similar,the principal component analysis method is improved.The correlation between the indexes,the importance of the indexes in the principal component and the contribution rate of the principal component are considered to avoid the calculation complexity and information overlapping caused by too many indexes Problems,as well as the disadvantages of too few indicators and information loss.2.In order to scientifically assign weights to evaluation indexes,AHP and entropy weight method are combined to determine comprehensive weights.In this process,entropy weight method is improved,which overcomes the instability of entropy weight when entropy value approaches 1 in traditional entropy weight method and the insensitivity of entropy weight when entropy value gap is large in previous improved entropy weight method.3.The result of bearing capacity calculation shows that the bearing capacity of agricultural water resources in Yanghe River Basin is in the range of 0.213-0.361,close to saturation state,and the potential of agricultural water resources development is small.It is suggested that effective measures should be taken immediately to improve the efficiency of water resources utilization and water environment.4.To solve the problem of unbalanced water supply,a water distribution method based on water demand characteristics and water shortage sensitivity is proposed,which can effectively reduce dimensions and improve the efficiency of model solution in order to avoid the occurrence of unbalanced water supply.At the same time,in order to improve the water quality and realize the full utilization of water resources,the method of water supplement and emission reduction is adopted to control the water quality.5.Taking 2014 as an example,through the optimization of the model in this paper,while the water quality of the assessment section is up to the standard,the agricultural water distribution is reduced by 3.38%,the economic benefit is increased by 11.96%,and the agricultural water resource carrying capacity is also increased to 0.214 ~ 0.376,which verifies the effectiveness of the model in this paper.Compared with other optimization models,the results further verify the feasibility and effectiveness of the model.In the end,the optimal allocation schemes of 2020 are compared and analyzed.The model is of great significance to the water quality safety and the sustainable development of regional economy in Yanghe River Basin.