An improved synthetic evaluation method on water quality evaluation in city sections of the Three Gorges reservoir area

The fuzzy synthetic evaluation and the grey clustering method are two typical synthetic evaluation methods that can be used in water quality assessment. The difference between these two methods is the weight chosen for clustering, while the clustering processes are nearly the same. This paper considered the merits of both these two methods in designing weight. The water quality assessment in 13 monitoring city sections of the Three Gorges reservoir area was taken as an example. The results showed that this improved method could objectively make different level among monitoring sections according to national water quality standard. The actual condition of the pollution could be clearly represented as well. Compared with other three representative methods, the result turned out to be more reasonable and closer to the fact.