The Application of Fuzzy Variable Sets Theory in Eutrophication Evaluation for Urban Lake

Abstract:

Eutrophication is one of the most serious water quality problems in the world. Urban lake eutrophication evaluation with the aim of improving urban water environment quality will provide foundations for urban water environment management and remediation. Considering that lake eutrophication evaluation involves many indexes, many rankings and interval values, fuzzy variable sets theory is applied. Based on the premise that the same mathematics model is used, index weights are determined by means of entropy value method, equal weight method and pure threshold value method. Relative membership degree of each index belonging to each ranking can be calculated with relative difference function model. At last, the stability of feature values of classification corresponding to three methods is analyzed and grade of each sample is determined. This model is applied to Lake Dongchang. Three lake regions all belong to the fifth ranking, namely eutrophic. It basically corresponds to reality. So it can be indicated that the proposed model is reasonable and practical.

• Periodical: Advanced Materials Research (Volumes 446-449)
• Pages: 2667-2672
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.446-449.2667
• Online since: January 2012
• Authors: Xiao Ping Zhang, Wei Guo Chen, Wen Jie Xu
• Keywords: Features of Classification, Fuzzy Variable Sets, Index Weights, Lake Dongchang, Urban Lake Eutrophication Evaluation

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