Identification of coastal water quality by multivariate statistical techniques in two typical bays of northern Zhejiang Province, East China Sea

The Hangzhou Bay (HZB) and Xiangshan Bay (XSB), in northern Zhejiang Province and connect to the East China Sea (ECS) were considerably affected by the consequence of water quality degradation. In this study, we analyzed physical and biogeochemical properties of water quality via multivariate statistical techniques. Hierarchical cluster analysis (HCA) grouped HZB and XSB into two subareas of different pollution sources based on similar physical and biogeochemical properties. Principal component analysis (PCA) identified three latent pollution sources in HZB and XSB respectively and emphasized the importance of terrestrial inputs, coastal industries as well as natural processes in determining the water quality of the two bays. Therefore, proper measurement for the protection of aquatic ecoenvironment in HZB and XSB were of great urgency.