基于博弈论赋权的灌溉用水效率GRA-TOPSIS评价模型

Evaluation Model of Irrigation Water Use Efficiency Based on Game Theory and GRA-TOPSIS

在构建区域灌溉用水效率综合评价指标体系的基础上,运用博弈论(Game theory,GT)思想将层次分析法(Analytic hierarchy process,AHP)所得主观权重与改进熵值法(Improved entropy value method,IEVM)所得客观权重进行综合集成以获取组合权值,并将灰色关联分析(Gray relation analysis,GRA)与逼近理想解排序(Technique for order preference by similarity to ideal solution,TOPSIS)相结合,以三江平原10个大型灌区为例进行验证,对区域灌溉用水效率作综合评价。采用Spearman等级相关系数检验灌溉水有效利用系数排序与GRA-TOPSIS法排序,得到的相关系数高达0.863,且GRA-TOPSIS法、GRA法、TOPSIS法对同一灌区综合排序的位次相差均不超过2,表明评价结果具有合理性和一致性;GRA-TOPSIS法所得综合值的极差为0.343,变异系数为0.267,均高于单独使用GRA法或TOPSIS法的极差与变异系数,更有利于对灌区灌溉用水效率进行辨识分区。此外,根据目标层与准则层排序差异度将灌区分为3类,辨识各灌区灌溉用水效率主控因子,对区域灌溉用水效率发展策略的制定具有参考价值。

An objective and comprehensive indicator system was established to evaluate the irrigation water use efficiency of irrigation districts. The subjective weights estimated by analytic hierarchy process （AHP） and the objective weights figured out by improved entropy value method （IEVM） were integrated through using the idea of game theory （GT） to gain a set of final indicator weights. The gray relation analysis （GRA） and technique for order preference by similarity to ideal solution （TOPSIS） model were combined to assess regional irrigation water use efficiency with combinational weights. Totally ten large- scale irrigation districts in Sanjiang Plain were chosen as the case study to validate this model and index system, and the evaluation results of the proposed GRA - TOPSIS method were compared with those of GRA and TOPSIS. The water use efficiencies of these irrigation districts were evaluated and ranked by the three methods, respectively. The results showed that the Spearman＇ s rank coefficients between the results of GRA - TOPSIS and those of GRA and TOPSIS were 0. 952 and 0. 927, respectively, which illustrated that the results of GRA TOPSIS were consistent with those of GRA or TOPSIS. The correlation coefficients between the effective irrigation water utilization coefficient and the results based on the GRA - TOPSIS method, GRA and TOPSIS were 0. 863, 0. 742 and 0. 736, respectively, implying that the GRA - TOPSIS was superior to GRA and TOPSIS. In addition, the range of comprehensive value obtained by GRA - TOPSIS model was 0. 343 with variation coefficient of 0. 267, which were all above the ranges and variation coefficients of GRA or TOPSIS methods, revealing a higher resolution ratio and evenness of GRA-TOPSIS model over those of the other two models. Therefore, the GRA - TOPSIS can efficiently assess the irrigation water use efficiency and lead to great convenience to the practice of water resources management. Meanwhile, the indexes of the criterion layer constituted by water-use index, engineering conditions and management level, were evaluated with GRA - TOPSIS. According to the degrees of variation between the ranks of criterion layer and the ranks of target layer, these irrigation districts can be divided into three categories so as to find out the main factors affecting each irrigation district. Wutonghe, Xingkaihn and Jiangchuan irrigation districts were in Ⅰ category, which should make all-round effort to build up the irrigation districts. Yintang, Yuelai, Jidong, Xingfu and Hamatong irrigation districts were in Ⅱ category, which should take advantage of the ranks of indicator layer to make further development strategy. Wokenhe and Longtouqiao irrigation districts were in Ⅲ category, which should make a great improvement in one aspect of criterion layer. In conclusion, the research provided references for evaluating regional irrigation water use efficiency and formulating development strategy for irrigation districts.