三峡水库小江库湾水体混合过程中营养盐的行为研究

Characteristics of Nutrients in the Xiangjiang Bay of the Three Gorges Reservoir

为研究三峡水库支流回水区营养盐的行为,2007年4月在小江库湾开展了现场调查,分层测定了水体中各形态营养盐、叶绿素a以及常量离子的含量。结果表明:干流和支流库湾总氮、总磷的主要组成部分是溶解无机氮、磷,干、支流氮、磷营养盐组成存在一定的差异,库湾内溶解有机氮、溶解有机磷浓度相对较高。干、支流水体的混合是控制库湾营养盐分布的主要原因,而生物活动的影响较小。

Water samples collected from the Xiaojiang bay were analyzed to investigate spatial variations of phosphorus, nitrogen and silicon species in the middle partion of the Three Gorges Reservoir. Dissolved inorgine nitrogen （DIN） represent 82.6% of the total nitrogen content in the Bay and 93.2% in the main channel of Yangtze River, respectively, which was the dominant N species in this area. The proportions of dissolved inorginc phosphorus （DIP） species in the total phosphorus are 67.6% in the bay and 74.1% in the main channel of the Yangtze River, respectively, which was the dominant P species. The distribution of nutrient is mainly controlled by the mixing process in the bay, while the contribution of phytoplankton is only of minor importance.