This study examined the temporal and spatial distribution characteristics and causes of water pollution in Dongting Lake based on water quality data from twenty sections of the lake and its inflow rivers and outlet from 2013 to 2022.The findings indicated that the annual average total nitrogen mass concentration ρ(TN)ranged from 1.21 to 2.60 mg/L in Dongting Lake,from 1.28 to 2.88 mg/L in the inflow rivers,and from 1.47 to 2.17 mg/L in the outlet.In addition,the annual average total phosphorus mass concentration ρ(TP)varied from 0.036 to 0.128 mg/L in Dongting Lake,from 0.035 to 0.167 mg/L in the inflow rivers,and from 0.048 to 0.132 mg/L in the outlet.The analysis revealed significant spatial differences and temporal variations in water quality.Spatially,the concentrations of TN and TP were higher in the inflow rivers compared to the outlet of Dongting Lake,while the outlet concentrations were greater than those in the lake body.Temporally,the concentrations of TN and TP exhibited a downward trend from 2013 to 2020,followed by a slowed decline or a significant increase from 2020 to 2022.Redundancy analysis further indicated that the water quality of Dongting Lake was influenced by its inflow rivers and fluctuations in lake water levels,as well as other pollution factors.These findings underscore the importance of enhancing the control of external pollutants and implementing active hydrological regulation across different hydrological stages to improve Dongting Lakes water quality.
关键词
洞庭湖/总氮/总磷/时空分布/污染评价
Key words
Dongting Lake/total nitrogen(TN)/total phosphorus(TP)/temporal and spatial distribution/pollution assessment
维普
万方数据