三峡水库4条支流的浮游植物生物量及其与环境因子的关系

Phytoplankton biomass and its relationship with environmental factors infour tributaries of the Three Gorges Reservoir

为了探究三峡支流水域浮游植物生物量的时空变化及其与环境因子的关系,于2019年1月到2020年1月在4条支流(小江、大宁河、神农溪、香溪河)开展水体叶绿素a和理化指标的逐月同步调查监测。结果显示,叶绿素a浓度在5月最高(29.802±19.970μg·L^(–1));1月最低(1.562±0.362μg·L^(–1)),叶绿素a年平均浓度为(10.810±10.908)μg·L^(–1)。空间上,重庆水域高于湖北水域,小江叶绿素a浓度最高。叶绿素a与理化因子的相关性分析和多元逐步回归分析结果表明,叶绿素a与总磷、溶氧、COD_(Mn)和水温存在显著正相关关系(P<0.05),与磷酸盐和透明度呈显著负相关关系(P<0.05);研究确认磷是三峡水库支流浮游植物生物量的主要控制因子,控磷对三峡支流藻类水华防控具有重要意义。

To reveal the relationship between phytoplankton biomass and environmental factors in tributaries of the Three Gorges Reservoir(TGR),chlorophyll a(Chl a)and physico-chemical factors of four tributaries(Xiaojiang,Daning,Shennongxi and Xiangxi)in the TGR were monitored monthly from Jan.2019 to Jan.2020.The results indicated that the concentration of Chl a was the highest in May and the lowest in January,which was(29.802±19.970)μg·L^(–1) and(1.562±0.362)μg·L^(–1),respectively.The annual average concentration of Chl a was(10.810±10.908)μg·L^(–1).The concentration of Chl a was higher in Chongqing area than in Hubei area,and the highest concentration was found in Xiaojiang.Correlation analysis showed that there was a significant positive correlation between Chl a and total phosphorus,dissolved oxygen,COD_(Mn),and water temperature(P<0.05),and a significant negative correlation with phosphate and transparency(P<0.05).It was proved that phosphorus was the main determining factor for Chl a,and phosphorus control was of great significance to the prevention and control of algal bloom in the tributaries of the Three Gorges Reservoir.