鄱阳湖水体富营养化评价方法及主导因子研究

Evaluation Method of Eutrophication in Poyang Lake and Its Leading Factors

运用Carlson综合指数法、灰色聚类法和主成分分析法3种方法,分别评估鄱阳湖2006年水体富营养化变化规律,筛选比较科学、先进的水体富营养化评价方法,并结合鄱阳历年来水质监测结果,分析研究鄱阳湖水体富营养化的主导因子,为控制鄱阳湖水污染提供理论依据。3种不同评价方法的评价结果相似,鄱阳湖枯水季节,水体呈富营养状态,丰水季节,水体呈"中营养-中富营养-中营养"的变化趋势。3种方法的评价结果差异说明主成分分析法比Carlson综合指数法和灰色聚类法更优越。化学需氧量、总氮、总磷是水体富营养的主导因子,总氮与总磷的比值与水体的富营养化相关性显著,因此,削减鄱阳湖水体中的氮、磷营养盐是控制水污染的主要措施。

Carlson integrated index method, grey clustering method and principal component analysis method were used to assess the rule of eutrophication of the Poyang lake in 2006, and explore the leading factors of eutrophication in the Poyang Lake according to the monitoring data in past years. The assessment results all indicated that the water body in the Poyang Lake was eutrophic during the low water level season, while the water body revealed the changeable trend of ＂moderate nutritive - moderate eutrophic - moderate nutritive＂ during high water level season. The difference in the assessment results showed that principal component analysis method was more advanced, scientific, and precise than the other two methods. COD, TN, and TP were the leading factors for eutrophication in the Poyang lake; above all, the ratio of TN to TP was significantly positively,correlated to eutrophication of water body, which urged that we ought to remarkably decrease N and P nutrient in the Poyang Lake in order to control the pollution to water body.