Temporal And Spatial Distribution Characteristics Of Nitrogen And Management Strategy In Baiyangdian Lake

This article regareded the Baiyangdian Lake as the research background.Base on the function in the history,the lake was divided into five functional areas,including the original natural area,tourist area,living area,breeding area and entrance area,respectively.The samples of 25 sampling points in five areas were collected in January,April,July and October 2019,which was mainly used to explore the spatial-temporal distribution of the nitrogen.A series of studies provided theoretical references for the control of nitrogen pollution in Baiyangdian lake.The main results were as follows:1)The concentrations of NH₄⁺-N,NO₃^--N and TN were among the range of0.01～0.53 mg·L^-1,0.01～3.21 mg·L^-1,0.84～3.26 mg·L^-1 in Baiyangdian throughout the year.The concentrations of NO₃^--N and TN in the lake of the entrance area and the breeding area were the highest.WQI results showed that the water quality of Baiyangdian Lake was in the“poor”range throughout the year,and the eutrophication of the overall water quality was more serious than 2018.2)The total nitrogen of sediments ranged from 2572.82 to 7398.39 mg·kg^-1,and the average concentration reached 2893.75 mg·kg^-1.The entrance area exhibited the highest total nitrogen concentration.Moreover,the significant difference was showed between interspace water and the overlying water based on the concentration of nitrogen nutrients.The WAEF-N which was the highest concentration among the four convertible nitrogen had a significant correlation with and NH₄⁺-N and NO₃^--N of interspace water and overlying water,suggesting that the sediments had a huge effect on water quality.3)Under the premise of effective control of external pollutants,the analysis of the release flux of endogenous nitrogen from summer sediments and the contribution rate to the water body showed that the release of endogenous nitrogen had a greater impact on water quality.Especially,the nitrogen releases in the entrance area and breeding area were more serious and had the greater impact on the overlying water.Principal component analysis showed that the sedimentary environments of entrance area were quite different.Therefore,in order to control the endogenous nitrogen,it was very important for the managers to distinguish the environmental characteristics of sediment.