关键词: 水质评价; Vague集; TOPSIS模型; 沱江;

Abstract: In order to solve the deficiency of traditional TOPSIS model in mining various indicators in a decision-making process,an improved TOPSIS model for water quality assessment was proposed by introducing Vague set into the ranking method of approximate ideal solution(TOPSIS).By normalizing the single-valued indicators of the original data,the decision data matrix of Vague set was established as a new decision matrix.And new positive and negative ideal solutions were defined according to the advantage function of Vague set,then the weighted distance and relative closeness degree of each scheme to the new ideal solution and negative ideal solution were calculated respectively.After that,the improved TOPSIS model was used to comprehensively evaluate the water quality of 14 surface water monitoring sections in the Tuojiang River Basin.The results obtained by this method were compared with the single factor index method,the comprehensive index method,the grey correlation method and the traditional TOPSIS method.The results showed that the improved TOPSIS model based on Vague set could ensure the maximum information mining of each indicators in the decision-making process,which was consistent with the evaluation results of other methods,and reflected water quality truly and effectively,indicating that this method is reasonable and feasible in water quality evaluation.

Key words: water quality evaluation; Vague set; TOPSIS model; Tuojiang River;