组合权重TOPSIS模型评价黄土高原小流域淤地坝系风险

Risk evaluation of check dam system in a small watershed of loess plateau using combined weight-TOPSIS method

黄土高原小流域淤地坝系水毁案例频发,开展坝系风险评价意义重大。在构建小流域淤地坝系风险评价指标体系的基础上,提出层次分析法和熵权法相结合的主客观组合权重赋权方法,规避权重计算只考虑主、客观单方面因素的影响,提高权重确定的准确性;基于逼近理想解法(TOP-SIS)构建小流域淤地坝系风险综合评价模型,实现多目标下的淤地坝系风险排序。将该评价模型应用于王茂沟小流域,得出其风险排序为:王茂沟2号单元<黄柏沟单元<埝堰沟单元<康和沟单元<关地沟单元<王塔沟单元,与实际相符,并亟需加强王塔沟坝系单元管护。采用Spearman等级相关系数检验法证明了组合权重TOPSIS模型评价结果的合理性。将灰色关联理论与组合权重TOPSIS模型进行同研究区坝系风险评价对比,得出组合权重TOPSIS模型在评价分辨水平和决策判断上更具优势。模型结果与实际情况基本相符,可为小流域淤地坝系风险评价提供技术参考。

The cases of check dam system damage in the small watershed in the Loess Plateau occur frequently,thus it is of great significance to carry out risk evaluation on the check dam system.Based on the risk evaluation index system of the check dam system in the small watershed,the subjective and objective combination weight empowerment method combining hierarchical analysis method and entropy weight method was put forward,which aims to avoid the shortcomings of considering only the subjective or the objective factors unilaterally and improve the accuracy of weight determination;The comprehensive risk evaluation model of the check dam system in the small watershed was constructed based on the technique for order preference by similarity to an ideal solution(TOPSIS)method,which can realize the risk ranking of check dam system under multiple objectives.The evaluation model was applied to Wangmaogou small watershed,and the risk ranking comes out as:Wangmaogou 2#unit<Huangbogou unit<Nianyangou unit<Kanghegou unit<Guandigou unit<Wangtagou unit.The results are consistent with the actual situation.And accordingly,it is urgent to strengthen the management and protection of Wangtagou dam system unit.Furthermore,the evaluation results of the combined weight TOPSIS model were justified using the Spearman rank correlation coefficient test.The gray association theory and the proposed combined weight TOPSIS model were adopted to perform the risk evaluation comparison of the dam system in the same study area.The results show that the combined weight TOPSIS model has more advantages in the resolution level and decision judgment.The evaluation results are basically in accordance with the actual situation,which can provide technical reference for the risk evaluation of check dam system in small watershed.