Abstract—Similarity measures were used to assess the water quality of 7 sites of Tai Lake in 2011. The data were collected once a week and there were 364 samples totally. In each samples, the concentrations of three indicators were collected: DO, COD, NH3-N. For the water quality data was a fuzzy set, semi-normal distribution membership functions were used to obtain the pollution condition of a given sample. The calculation results of fuzzy entropies were used to determine the weights of the indicators. The weight of DO was higher than the other two indicators. This also explained the affection of DO on other indicators. The similarity degree of the results of three similarity measures was 76.10%. This illustrated that they were suitable to determine the water quality ranks. Hamming similarity measures and Euclid similarity measures gave 94.51% of the samples the same water quality ranks. The sample site Jishuigang, Shanghai City was taken to illustrate.

Index Terms—Water quality assessment, similarity measures, fuzzy entropy, entropy weights.

Xiaojing Wang, Zhihong Zou, and Tianyi Fu are with the School of Economics and Management of Beihang University, Beijing 100191 China (e-mail: star_wxj@126.com, zouzhihong@buaa.edu.cn, sophia_1118@sina.com).

 

Cite:Xiaojing Wang, Zhihong Zou, and Tianyi Fu, "Fuzzy Entropy and Similarity Measures for Water Quality Assessment," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 3, no. 6, pp. 593-597, 2013.