On the basis of Euclidean distance model with weights

this study improved the calculation of the weights. The weights were added to pollution factors according to different pollution contribution rates. The level I of surface water environmental quality standards was taken as the 'coordinate origin'. The Euclidean distances with varying weights between units and 'coordinate origin' and between other levels of surface water environmental quality standards and 'coordinate origin' were calculated. The latter served as a distance level evaluation criteria. The Euclidean distance model with varying weights was established

which is suitable for assessment of surface water quality. This model was applied in comprehensive assessment of water quality

using the monitoring water quality data obtained from 1996 to 2006 in Xucun section of the Dongyang River

a tributary of the Qiantang River. The outcome was compared with that of grey clustering model and fuzzy complex index method. The results showed consistence with actual water quality situation

indicating that the Euclidean distance model with varying weights has potential application in comprehensive assessment of surface water quality.