三峡工程运行对洞庭湖浮游植物群落及水质的影响

摘要

Based on investigation of species and quantity of phytoplankton and some important physicochemical indicators in Dongting Lake before and after impoundment of the Three Gorges Project（TGP）,we discussed the effects of the TGP running on phytoplankton community and water quality in the Lake.The results showed that a series of changes of physicochemical indicators in water column were found in the lake after running the TGP,such as decreasing silt content,increasing transparency,reducing water environmental capacity and slower water flow velocity.In recent years,increasing nutrient pollution load（especially nitrogen and phosphorus） resulted in that species and quantity of phytoplankton in Dongting Lake had elevated,which led to some parts of Dongting Lake was in mild eutrophic state.%通过分析三峡工程蓄水运行前后洞庭湖水体中浮游植物种类和数量以及重要理化指标的变化,可以发现三峡工程对洞庭湖浮游植物群落及水质的影响。研究结果表明：三峡工程运行后洞庭湖水体理化性质发生了一系列变化,具体表现为：水体含沙量下降,透明度增加,水体环境容量减小,水体流速减缓。近年湖体氮、磷等营养盐污染负荷有所加重,洞庭湖的浮游植物种类和数量均有所增加,洞庭湖局部区域已出现了轻度富营养化状况。