2013—2022年白洋淀水体富营养化时空变化特征研究

Spatial and temporal characteristics of eutrophication in Baiyangdian Lake from 2013 to 2022

作为华北平原最大的淡水湖泊,白洋淀水质安全与区域生态环境健康息息相关。基于2013—2022年逐月监测数据(总磷(TP)、总氮(TN)、叶绿素a(Chl-a)、溶解氧(DO)、化学需氧量(COD)、五日生化需氧量(BOD_(5))、氨氮和高锰酸盐指数),采用综合营养状态指数(TLI(Σ))揭示了白洋淀水体营养状态分布特征,以期为未来白洋淀水质提升工作提供科学依据。结果显示,2022年白洋淀水体处于中营养状态,TLI(Σ)较2013年下降6%。白洋淀水体营养程度呈现西高东低特征。2022年南刘庄在春季和夏季处于轻度富营养状态,春季属于磷限制,夏季属于氮+磷双限制,春、夏季应严格管控入淀水中氮、磷的浓度;采蒲台在夏季处于轻度富营养状态,属于磷限制,应通过控制底泥释放、加强水草收割管理等措施控制其夏季水体中磷的含量。

As the largest freshwater lake in the North China Plain,Baiyangdian’s water quality safety is closely related to the health of the regional ecosystem.Based on the monthly monitoring data(TN,TP,Chl-a,DO,COD,BOD_(5),ammonia nitrogen and permanganate index)from 2013 to 2022,this paper revealed the spatial and temporal distribution characteristics of eutrophication in Baiyangdian Lake by using the trophic level index(TLI(Σ)),which was expected to provide scientific basis for the effective improvement of Baiyangdian Lake water quality in the future.The results showed that TLI(Σ)in Baiyangdian Lake decreased by 6%compared with 2013.The overall water quality was in mesotrophic status.The eutrophication degree of Baiyangdian Lake was high in the west and low in the east.Nanliuzhuang experienced light eutrophication in both spring and summer in 2022.The spring was phosphorus-limited,while the summer was limited by both nitrogen and phosphorus,so nitrogen/phosphorus concentration in the inflow river should be strictly controlled in spring and summer.Caiputai exhibited light eutrophication in summer,characterized by phosphorus limitation.Controlling the release of sediment and strengthening the management of aquatic plant harvesting were effective measures to regulate the phosphorus content in the water body in summer.