Water quality pollution characteristics in East Taihu Lake

Principal component analysis and cluster analysis were used to analyze the spatial zoning of water quality and the main water pollution characteristics in East Taihu Lake based on a systematic water environment research.The results showed that there existed a significant spatial pattern and obvious seasonal variations in water quality characteristics among the sites selected in East Taihu Lake.Two main components were obtained from twelve water quality indices,and component I was characterized by total phosphorus total dissolved phosphorus and inorganic phosphate concentration.Components II was associated with Chla and CODMn which represented water organic pollution in East Taihu Lake.Twelve sample plots were classified into four classes by cluster analysis in terms of principal component scores.The water pollution was highly in the river mouths of the north part of East Taihu Lake due to the discharge of urban domestic sewage,especially in the Youchegang mouth.The water quality in the crab's enclosure culture area was as good as the sites in the south and east parts in East Taihu Lake because of the artificial grown vegetation's strong purification ability.