Integrated oxygen consumption characteristic and influencing factors in inflow river impact zone of Baiyangdian Lake
Regarding the phenomenon of low dissolved oxygen(DO)concentration in the affected area of the Baiyangdian River during summer,this study employed time series analysis of water quality data,comprehensive oxygen consumption experiments on water bodies,and correlational statistical analysis to research the diurnal variation patterns of dissolved oxygen(DO)concentration at the Nanliuzhuang national control section within the Fu River's influence zone,the water oxygen demand over different underlying surface types,and their influencing factors during summer.The results showed that the DO concentration at the Nanliuzhuang section exhibited a seasonal pattern of higher levels in spring and autumn and lower levels in summer,with the concentration dropping to around 1.5 mg·L-1 in summer of 2022 despite overall improvements in water quality over the years.The daily fluctuation range of DO concentration varied between 0.5～5.7 mg·L-1,with an average of 2.3 mg·L-1,showing a trend of summer＞spring＞autumn.The water oxygen demand in the Fu River's influence zone ranged from 0.024 0 to 0.049 9 mg·(L·h)-1,with the water bodies showing a pattern of canal ≈ lake surface＞ditch in terms of different underlying surface water types.The water oxygen demand generally exhibited a trend of bottom layer＞surface layer and middle layer across different depths.The ratio of sediment oxygen demand to water oxygen demand in the comprehensive oxygen consumption rates of water bodies was 1.55,indicating that both water and sediment oxygen demand significant reasons for the low DO concentration.The annual variation trend of DO concentration at the Nanliuzhuang section showed a significant negative correlation with chlorophyll a(Chla)content(p＜0.01),turbidity(p＜0.01),and CODMn concentration(p＜0.01),and the water oxygen demand was significantly positively correlated with chlorophyll a(Chla)content(p＜0.01),DOC concentration(p＜0.05),and CODMn concentration(p＜0.05).Reducing the turbidity of river inflows,suppressing the explosive growth of phytoplankton in the river inflow influence area during summer,and periodically conducting ecological dredging to reduce the high oxygen consumption background caused by sediment and pore water pollutant diffusion were fundamental to ensuring the stable achievement of Class Ⅲ water quality standards in Baiyangdian Lake.
Baiyangdian Lakeinflow river impact zone of Baiyangdian Lakedissolved oxygenwater comprehensive oxygen consumptioninfluencing factors
万方数据
维普
