熵权法在地下水环境质量评价中的局限性

Disadvantages of entropy weighting model in the groundwater quality evaluation

以西北某镇的浅层地下水水质评价为例,揭示了熵权法的2项不足:熵权法仅仅考虑了指标统计意义的重要性,而没有考虑它们在水资源管理中的实际意义,这可能导致污染严重的指标权重过小;熵权法在标准化结果中具有失真现象,可能导致污染较轻的指标权重过大。这2个缺点会使得综合评价结果过于乐观,因此熵权法求得的权重不能直接用于地下水水质评价。进行综合评价之前,应当首先对熵权法求得的权重参数进行合理性分析。

This study takes the groundwater quality evaluation in a northwest town as an illustration to reveal two disadvantages of the entropy weighting model.Entropy weighting model only takes the statistical significance of the indicators into consideration,but neglects their practical meaning in the groundwater quality assessment,which may reduce the weights of heavily polluted indicators. Entropy weighting model has distortion phenomenon in the standardization results,which may enlarge the weights of clean indicators.These two disadvantages make the evaluation result over-optimistic. Therefore,the weights parameters generated by entropy weighting model cannot directly used in the groundwater quality evaluation without reasonableness analysis.