Abstract:

In this study，multiple statistical methods were conducted to evaluate water quality in the inflow and outflow rivers of Lake Taihu，China.Hierachical cluster analysis indicated that the inflow and outflow rivers of Lake Taihu can be classified into three categories according to their water quality.Principal component analysis，which is used to identify the possible factors or/and sources that determine river water quality，indicated that water quality of these rivers was generally determined in nutrient order of nitrogen and phosphorus levels.Principal component analysis also indicated that water quality of Category I rivers was mainly determined in nutrient order of nitrogen and phosphorus，that water quality of Category II rivers was mainly determined in order of nitrogen and organic matter levels，and that water quality of Category III rivers was mainly determined in order of phosphorus，organic matter and nitrogen levels.〖