三峡水库夏季支流水体营养状态及趋势预测

Trophic States and Eutrophication Forecast of the Three-gorges Reservoir's Tributaries in Summer

2004年夏季，对受三峡水库蓄水影响的12条次级河流库湾夏季水体营养化程度进行了调查。DO含量范围在2．20～10．1mg／L；透明度范围在0．1～1．0m；CODMn范围在1．60～9．79mg／L；TN范围在0．72～5．27mg／L；TP范围在0．013-0．369mg／L；叶绿素a范围在1．54～20．0mg／m^3。综合营养状态指数法评价的结果表明，各条次级河流的综合营养状态指数范围为39．2～69．2，其中8条河流达到富营养化水平，4条中营养。运用模型预测了三峡水库175m蓄水后叶绿素a含量，范围在8．73～33．6mg／m^3，其中10条支流达到富营养化水平，2条为中营养。表明三峡水库支流水体富营养化程度将有加重趋势。

Water quality of tributaries in Three Gorges Reservoir were investigated in 2004 summer. DO, SD, CODMn, TN, TP and Chla ranged from 2.20-10. 1 mg/L, 0.1-1.0 m, 1.60-9.79 mg/L, 0.72- 5.27 mg/L, 0. 013-0. 369 mg/L, 1.54-20.0 mg/m^3 respectively. Utilizing the method of integrated nutrition state index, it assessed the trophic states degree of tributaries. Integrated nutrition state index ranged from 39.2-69.2. In all of the studied tributaries, 8 tributaries are eutropher, 4 are mesotropher, respectively. The eutrophication trend is forecasted with model after 175 m storage water. Concentration of Chla would be ranged from 8.73-33.6 mg/m^3. It indicated that 10 tributaries would be eutropher and 2 mesotropher, respectively. Eutrophication trend of tributaries estuaries would be more serious.