三峡库区蓄水后支流回水段富营养化研究

Study on the Eutrophication in Backwater Area of Branches After Storage of Three Gorges Reservoir

为掌握三峡水库蓄水后支流回水段的营养特征及其变化情况,2004年4月分别对大宁河、神女溪、抱龙河与大溪河回水段水体进行了富营养化调查和监测,调查监测的项目包括透明度、总氮、总磷、高锰酸盐指数和叶绿素a等重要指标。并运用综合营养状态指数法对监测结果进行了评价与相关性分析,初步研究了支流回水段水体的水质状况。结果表明库区支流回水段的营养盐浓度并不比长江干流高,但库区支流回水段的中下游区域已经发生了轻度富营养化;相关公式的建立有助于掌握支流回水段的水质状况;叶绿素a与氮、磷等营养盐呈现较好的正相关关系,与透明度和电导率则呈较显著的负相关关系。

In order to comprehend the nutrition characters and tendency of branch’s backwater area after the storage of Three GorgesReservoir,the eutrophication and water quality of Daning River,Shenn’ River,Baolong river and Daxi river were investigated in May,2004. Theparameters of water quality included transparency(SD),chemical oxygen demand(CODMn),total nitrogen(TN),total phosphorus(TP)andchlorophyll-a(Chl-a). The water quality of branch’s backwater area was analyzed according to the monitoring results,and the Trophic Level In-dex(TLI)and the correlativity among parameters were calculated. The concentration of nutrition in backwater area is not higher than that inYangtze River,but light eutropher has been found in the middle and lower reaches of backwater areas of branches. Correlativity formulas arepropitious for understanding the water quality of backwater area. The correlativity between chlorophyll-a and the parameters of nitrogen andphosphorus is positive,but the correlativity between chlorophyll-a and the parameters of transparency and electric conductivity is negative.