摘要
白洋淀是华北平原上最大的草型浅淀,最大蓄水量为10.4×10^(8) m^(3),总面积约为366 km^(2)。白洋淀上游流域共有8条入淀河流,淀区内现行的补水方案包括“引黄入淀”补水、“西大洋和王快水库”补水和“南水北调”补水等。近年来,由于人类活动的剧烈干扰,白洋淀水环境质量在不断变差。为了提高白洋淀的水环境质量,不仅要控制外源污染物的排入,而且更要消减内源污染。以采蒲台水域的水质改善综合治理工程为案例,模拟研究水质改善综合治理工程对该区水动力、水质和水交换的影响。采蒲台水域位于白洋淀东南部,北接安新县,南邻任丘市,总面积为0.6 km^(2)。应用MIKE 21软件,构建了水动力和水质模型,在未实施和实施了水质改善综合治理工程条件下,模拟了采蒲台水域的水交换和水质状况。研究结果表明,采蒲台水域的流场主要由风速场主导,水体流动速度普遍较小;水动力模拟结果显示,在实施了拆除围埝和清淤0.4 m等工程的条件下,采蒲台水域水体更新时间(37 d)更短,平均水交换率(0.868)更大,采蒲台区域水交换能力变强,有利于水体中污染物的稀释和扩散;水质模拟结果显示,在实施了工程的条件下,在水体结冰期间,采蒲台水域水体中的化学需氧量、氨氮和总磷含量都大幅度减小,冰面融化后,因风场扰动,使底泥中污染物的释放通量增大,导致水体中的化学需氧量、氨氮和总磷含量都波动增大;白洋淀水体的富营养化程度可以利用营养状态综合指数进行判定,从营养状态综合指数的时间变化上看,在模拟初期,采蒲台水域水体严重富营养化,当“引黄入淀”补水时,采蒲台水域的水环境质量有所好转,在实施了工程的条件下,水体处于中营养化状态,营养状态综合指数的最小值为29.54,说明拆除围埝和清淤等水质改善工程可以在一定程度上降低采蒲台水域水体的富营养化水平。
Baiyangdian Lake is the largest shallow lake in the North China Plain,belonging to grass type lake.The maximum water storage capacity of Baiyangdian Lake is 1.04×10^(8) m^(3),and its total area is about 366 km^(2).Eight rivers flow into Baiyangdian Lake from the upstream watershed.The current water transfer schemes for the lake area include water transferred from Yellow River,Xidayang Reservoir and Wangkuai Reservoir,South-North Water Transfer Project and so on.In recent years,water quality of Baiyangdian Lake gradually declined due to the aggravation of human activities.In order to improve water quality of the lake,exogenous pollutants should be controlled.Besides,internal pollutants should also be reduced.Taking the comprehensive project on improving water quality of Caiputai water area as an example,this study simulated and analyzed the effects of the project on hydrodynamics,water quality and water exchange in this area.Caiputai water area is located in the southeast of Baiyangdian Lake,and it is connected with Anxin county in the north and Renqiu city to the south.The total area is 0.6 km^(2).Based on MIKE,a hydrodynamic and water quality model was established.Under conditions of unimplemented and implemented treatment projects,the water exchange and water quality were simulated.The results showed that the flow field was mainly dominated by wind speed field and water velocity was generally small in this area.The hydrodynamic simulation results showed that the renewal time of water body was shorter(37 d)and average water exchange rate was higher(0.868)in Caiputai water area under condition of demolishing the cofferdam and removing 0.4 m of silt.The water exchange capacity of Caiputai water area promoted,which was helpful for the dilution and diffusion of pollutants in water body.The simulation results of water quality showed that during the icing time,concentrations of chemical oxygen demand,ammonia nitrogen and total phosphorus greatly decreased in this area under condition of implementing treatment project.After the ice melts,the release of sediment pollutants increases due to the disturbance of wind field.Thus,concentrations of chemical oxygen demand,ammonia nitrogen and total phosphorus entirely increased.The eutrophication degree of Baiyangdian Lake could be determined by comprehensive index of trophic state.From the time change of comprehensive index of trophic state,the water body of Caiputai water area was seriously eutrophic at the beginning of simulation.When water transferred from Yellow River discharge into the lake,water quality of Caiputai water area was improved.The trophic state of water quality was mesotropher under condition of implementing treatment project.The minimum value of the comprehensive index of trophic state was 29.54.It indicated that the eutrophication degree could be decreased by implementing comprehensive treatment projects of water quality such as demolishing cofferdam and removing silt.
作者
傅长锋
陈平
武亚辉
尤学一
尹健婷
FU Changfeng;CHEN Ping;WU Yahui;YOU Xueyi;YIN Jianting(Hebei Research Institute of Investigation and Design of Water Conservancy and Hydropower,Tianjin 300250,P.R.China;School of Environmental Science&Engineering,Tianjin University,Tianjin 300072,P.R.China)
出处
《湿地科学》
CSCD
北大核心
2021年第6期651-658,共8页
Wetland Science
基金
河北省水利科研与推广计划项目(2017-06)
天津市重点研发计划项目(18YFHBZC00010)资助。
关键词
水交换
水质
模拟
MIKE模型
富营养化
采蒲台
白洋淀
water exchange
water quality
simulation
MIKE model
eutrophication
Caiputai
Baiyangdian Lake
