The trend and downside risk of water quality evolution in Dongting Lake in recent 25 years
LIN Ri-peng1,2,3, Ni Zhao-kui2,3, GUO Shu-kun2,3,4, GONG Jia-jian2,3,4, WANG Sheng-rui1,2,3,4
1. Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Resources Environmental & Chemical Engineering, Nanchang University, Nanchang 330031, China;
2. College of Water Sciences, Beijing Normal University, Beijing 100875, China;
3. Chinese Research Academy of Environmental Sciences, Beijing 100012, China;
4. College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002, China
The evolution characteristics of water quality and major driving factors were investigated by using the data from 1991 to 2015 in Dongting Lake. The effects of declining of water quality on aquatic ecological risks also discussed in this study. The results showed that the water quality declined from 1991 to 2015. TN and TP were the major indexes that caused water quality decline, with the concentrations ranged from 1.06~2.07 and 0.026~0.146, respectively. From 1991 to 2002, the concentrations of TN and TP increased significantly, which could be the effects of water level and sedimentation according to the multiple regression analysis. From 2003 to 2015, TN concentration continuous to increase but TP was relatively stable, which resulted from nitrogen and phosphorus load input and water level. The level of ecological risk of Dongtimg Lake transformed from slightly to moderately from 1991 to 2015. The flood and enhanced agricultural nonpoint source pollution and urbanization were the main drivers, from 1991~2008, the risk all increased in different, especially in western district of Dongting Lake. From 2009 to 2015, the risk in different regions declined, the decrease of eastern district were more significant than western district. Therefore, to protect aquatic ecosystem of Dongting Lake, optimization of hydrologic condition, control of nutrients loading and particular focus on P risk were the most important strategies.
林日彭, 倪兆奎, 郭舒琨, 龚佳健, 王圣瑞. 近25年洞庭湖水质演变趋势及下降风险[J]. 中国环境科学, 2018, 38(12): 4636-4643.
LIN Ri-peng, Ni Zhao-kui, GUO Shu-kun, GONG Jia-jian, WANG Sheng-rui. The trend and downside risk of water quality evolution in Dongting Lake in recent 25 years. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(12): 4636-4643.
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