Analysis And Evaluation Of Water Resources System Based On Projection Pursuit

Water resources system is a complex open giant system.The analysis,evaluation,and decision-making on water resources system are related to all aspects of the system.Solving the index weight scientifically and reasonably,and then to build an accurate and effective evaluation model is the precondition to provide decision support and information support for water resources planning and management.It is of great significance for the coordinated and sustainable development of water resources and economic society,and it is also an urgent task and important topic for the current water resources decision makers.Based on the study of the complexity of water resources system analysis and evaluation and the importance of reasonable weight solution,aiming at the relationship between index weight and index sample value in water resources system analysis and evaluation,considering the high-dimensional nonlinear attribute of index value involved in water resources system analysis and evaluation,this paper proposes PP-based method,the weight optimization method based on projection pursuit(PP-AHP)and the dynamic weighting method based on projection pursuit(PP-DW)are constructed.By combining the weight with the subtraction set pair potential theory,the comprehensive evaluation model of water resources carrying capacity based on PP-AHP weight optimization and the optimization model of water conservancy project scheme based on PP-DW method are further constructed,The above two models are applied to the analysis and evaluation of actual water resources system,the main results are as follows:(1)In order to further mine the information of index weight changing with water resources evaluation index,PP-AHP method is proposed.This method can further optimize and refine the index weight under the complex situation of multi-objective,multi-level and multi criteria in the actual system.This weight not only retains the advantages of close to the actual situation,but also avoids the shortcomings of excessive human intervention,and is closer to the optimal solution.It shows that PP-AHP is reasonable,which can provide provide a new idea for solving the weight.(2)In order to evaluate the carrying capacity of regional water resources reasonably,a comprehensive evaluation model of water resources carrying capacity based on PP-AHP weight optimization was constructed,and appling this model to the comprehensive evaluation case of water resources carrying capacity in Anhui Province from 2005 to 2015.The comprehensive evaluation results show that: the comprehensive evaluation grade results are consistent with average correlation number model and correlation entropy method,which indicates that the model is reasonable.In addition,the fluctuation of the evaluation results of the model is more stable than the correlation entropy method and the average correlation number model,which is more in line with the actual situation that the water resources carrying capacity presents a stable and good development under the governance of relevant departments,which shows that the model has strong anti-interference ability,and is not easy to have abnormal undulations and variations.(3)In order to further mine the information that the index weight changes with the evaluation index sample,the PP-DW method is proposed.This method obtains the dynamic weight,which can be adaptively weighted with the change of the actual value of the index.This weight can well reflect the difference between different schemes.As the basis of decision-making and diagnosis of main influencing factors,dynamic weight shows certain advantages in different schemes and indexes.It can effectively reduce the decision errors caused by unreasonable static weight,improve the rationality,reliability and accuracy of scheme decision,and provide a new method for soiving the dynamic weight..(4)In order to mine the information that the index weight changes with the evaluation index sample in the optimization of water conservancy project scheme selection,a water conservancy project scheme selection model based on PP-DW is proposed.The model is applied to the optimization evaluation of the reconstruction and expansion planning scheme of an irrigation area.The evaluation result shows that the comprehensive ranking results under the model are basically consistent with those under TOPSIS-PP,AGA-FAHP and OCEM,which indicates that the model is reasonable.In addition,the application process of this model is simpler,which can not only effectively avoid the adverse impact of static weight on scheme decision-making,but also accurately and efficiently identify every index's impact on the comprehensive evaluation results.The evaluation results are more objective,stable and general.To sum up,based on the research and analysis of water resources system and its complexity characteristics,this paper has proposed weight optimization method and dynamic weighting method based on PP.On this basis,the comprehensive evaluation model of water resources carrying capacity and the optimization model of water conservancy project scheme in Anhui Province are established.The evaluation results of the two models are objective and reasonable,which are in line with the actual situation.The two models have achieved good application results,which can provide a certain method reference for the quantitative evaluation of related problems in water resources system,and also can provide theoretical support for decision makers to make reasonable decisions.