三峡水库蓄水前后大宁河水体中营养盐时空分布及水质变化趋势探讨

通过分析历年监测资料，研究了三峡工程蓄水前后大宁河水质时空变化状况。结果表明：整体上三峡工程蓄水前后大宁河水质类别未发生变化，营养盐指标中氨氮较蓄水前有明显的下降；其它营养指标变化较复杂；从上游至下游，各营养盐指标呈上升趋势，较长江干流营养盐水平要低；另外受干流回水顶托，致使水流回水区流速变缓，部分河段出现了富营养化现象。

Analysis of Nutrients Distribution in Daning River before and after Impoundment of the Three Gorges Project

The changes of water quality of Daning river before and after impoundment of the Three Gorges project are studied based on analyzing the past years＇monitoring data. The results indicated that the water quality classification of Daning river has no change before and after impoundment of the Three Gorges project. The ammonia decreased distinctly after impoundment, and other nutrient indexes showed complicated changes. The nutrient indexes increased lower than the level of the Long River from upstream to downstream. Additionally, algae bloom usually emerges in some reaches due to backwater jacking.