Analysis about Mechanism of Pollution in Shallow Weedy Lakes in Arid Area

Lake Wuliangsuhai is typical shallow weedy lake in arid area in north of China. In this paper, Lake Wuliangsuhai is recognized as study area. The data of water quality from June to October in 2005 are analyzed using principal components analysis. The parameters about water quality of Lake Wuliangsuhai are generalized into sever principal components. They are index about characters of eutrophication, index about characters of salinization, index about organic pollution, index about configuration characters of lake, index about acid and alkali, index about living amount and index about environment of plant growing. The meaning of each principal component and the mechanism about pollution of Lake Wuliangsuhai are concluded. The conclusions indicate that the water quality of Lake Wuliangsuhai mostly is controlled by the first principal component ( index about characters of eutrophication), and it secondly is controlled by the second and third principal components ( index about characters of salinization and index about organic pollution). So Lake Wuliangsuhai encounters three menaces of pollution. They are eutrophication, salinization and organic pollution. Eutrophic pollution is the worst pollution. The principal factors that influence water quality of lakes are concluded, and the scientific gist of reasonable using water resource of lakes and fathering eutrophication are provided.