Investigation and Eutrophication of Water Quality in a Lake District
Taking a lake body as the research object,permanganate index,chemical oxygen demand(COD),total nitrogen(TN),total phosphorus(TP),ammonia nitrogen(NH4+-N),chlorophyll a(Chl-a),lake clarity(secchi disk depth,SD)and other water quality indexes during 2011-2020 were investigated and analyzed,with reference to the surface water environmental quality standard(GB3838-2002)and the Surface Water Environmental Quality Evalu-ation Measures(Trial).The results showed that TP of the lake area in the past ten years was basically stable at the level of Class Ⅲ,except for 2017-2019,when it exceeded the standard of Class Ⅳ.TN had been exceeding Class m in 2011-2020,reaching a peak of 3.4 mg/L in 2016,and then decreasing to about 1.3 mg/L,but it increased slightly after 2018.Combined with the decreasing trend of concentration of NH4+-N during this period,it was found that the input of organic nitrogen and inorganic nitrogen in the lake increased.Through intensive monito-ring analysis of the water quality of the lake,the concentrations of TN and TP were higher near the east and south shores of the East Lake,and the concentrations of Chl-a were higher near the north of East Lake and the polder area in the northwest of West Lake.By comparing the eutrophication index,since 2014,the rich nutrition level of the lake showed a significant upward trend,and the index of West Lake was a higher than that of East Lake.
lake bodieswater quality indexesintensive monitoring analysiseutrophication
万方数据
维普
