Application of Grey Clustering method for water quality evaluation in fenchuan River Yan´an Baota Area

Methods, steps of evaluation with Grey Clustering method for water quality were introduced, applied in evaluating water quality of Fenchuan river in 2008. According to the clustering coefficient: the water quality of Jinjiabian and the main stream of Madongxiang was relatively good, which was at the second-grade and slightly contaminated; while the water quality of the main stream of downstream Linzhengzheng and the outflow of Guanzhuang was at the-fifth grade and seriously contaminated. With the evaluation for the water quality of Fenchuan river, it will give reference to wastewater treatment and environmental protection.