Research On Comprehensive Evaluation Of Regional Irrigation Water Use Efficiency And Its Effect On Water Resources System Resilience

Irrigation water use efficiency is an important basis to evaluate the effectiveness of water-saving transformation in irrigation districts,and to evaluate the effective utilization of irrigation water and the existing problems.Accurate,objective and quantitative evaluation of regional irrigation water use efficiency is an important research topic of water-saving irrigation,which is of great significance to the implementation of the most stringent water resources management system.Irrigation water use efficiency is also an important factor for water resource system resilience,but there are few studies about that at home and abroad,so it is of great theoretical and practical significance to carry out comprehensive evaluation of regional irrigation water use efficiency and to study the response effect of water resources system restraint under irrigation water use efficiency constraints.In this paper,10 large-scale irrigated districts,10 medium irrigation districts and 10 small-sized irrigation districts in Sanjiang Plain were selected as the study points,and the irrigation water use efficiency of the above-mentioned irrigation districts in 2013 was evaluated comprehensively.On the basis of this,the water resources system resilience state of Jiangchuan irrigation district and Wutong River irrigation district in 2011-2015 was evaluated.The main contents and findings of the study are as follows:(1)Study on comprehensive evaluation model of regional irrigation water use efficiencyBy analyzing the influence factors of irrigation water use efficiency,a comprehensive indicator system was established to evaluate the regional irrigation water use efficiency of irrigation districts.Applying the game theory(GT)to coordinate the objective weights estimated by improved entropy value method(IEVM)and the subjective weights figured out by analytic hierarchy process(AHP)to gain combinational weights.Using GRA model,TOPSIS model and GRA-TOPSIS model respectively,the irrigation water use efficiency of large-scale,medium and small-sized irrigation districts in Sanjiang Plain were calculated and analyzed,then the comprehensive index of irrigation water use efficiency in each irrigation district are obtained.Through comparing the reliability and robustness of each evaluation model then the conclusion that GRA-TOPSIS model is the optimal evaluation model is drawn.(2)Identification of main factors affecting regional irrigation water use efficiencyThe comprehensive evaluation system of irrigation water use efficiency was deconstructed then the GRA-TOPSIS model was used to sort the target layer and the criterion layer respectively,and then the original data of the index layer was sorted.Then the order of the three-layer structure was compared,and main factors affecting water resources use efficiency of different irrigation areas are discriminated.This can provided targeted and practical theoretical guidance for development of water-saving agriculture in irrigation areas;Spatial distribution map is drawn using GIS to visualize the comprehensive ranking and criterion layer ranking of each irrigation district,which can make readers understand the discrimination condition of main factors intuitively,conveniently and efficiently.(3)Analysis on the characteristics of regional water resources resilienceExplored the basic characteristics and connotation of resilience,the essential characteristics and laws of water resources system then characteristics of water resources system was obtained according to the inherent attributes of resilience and water resources system from the view of system theory and ecology theory.Then the comprehensive evaluation index system of regional water resources resilience under irrigation water use efficiency constraint was constructed based on DPSIR.(4)The response characteristics of regional water resources system resilience to irrigation water use efficiencyThe irrigation water use efficiency was innovatively defined as a factor of "State" in the water resources system resilience DPSIR model.Then the resilience state of water resources system considering irrigation water use efficiency was explored using SPSS Statistic 22 software based on principal component analysis.The response characteristics of regional water resources system resilience to irrigation water use efficiency was studied,and we can come to a conclusion that there is a strong positive correlation between the irrigation water use efficiency and water resources system resilience.