Abstract:

Since 2003 after impoundment of Three Gorges Reservoir its tributary-Daning River began with frequent water blooms,and its frequency is increasing and expanding.Chlorophylla (Chla) is a wellaccepted index for phytoplankton abundance and primary productivity in an aquatic environment.The relationships between Chla and 11 water quality indices in Daning River were studied by principal component scores in multiple linear regression analysis.Principal component analysis was used to simplify the complexity of relations between water quality indices.Score values obtained by principal component scores were used as independent variables in the multiple linear regression models.The results showed that log(Chla) was found to have significant linear relationship with 6 score values from the principal component analysis of variables, and predicted Chla values of Daning River were obtained from the following model:log(Chla) = 0.579-0.191× (Score 1)-0013×(Score 2)-0013×(Score 3)+0042×(Score 4)+0134×(Score 5)-0059×(Score 6),〖WTBX〗R〖WTBZ〗=0731 and 〖WTBX〗R〖WTBZ〗2 (goodness of fit)=0535,indicating that 535% of variation in Chla could be estimated by this modeling approach.The results of further validation using a new dataset suggested that the modeling obtained in this study successfully simulated Chla peak concentrations and developed tendency from January to October in 2010