Variable Fuzzy Set Theory to Assess Water Quality of the Meiliang Bay in Taihu Lake Basin

The water quality assessment is a fuzzy concept with multiple indicators and classes. Because of subjectivity in determining index weight and assessment standard as point forms in water quality assessment, evaluation results are often incompatible and independent, and sometimes with unreliable conclusions. An assessment model is developed, based on the variable fuzzy set and the information entropy theory. The model is applied to assess the water quality status of the Meiliang Bay of the Taihu Lake in China. Results show that the proposed model can determine the water quality level and provide an acceptable alternative based on optimized objectivity in determining water quality level. This study could provide a scientific basis for analyzing and evaluating the water quality for environment management.