TY - JOUR
T1 - Optimizing nitrogen management for pollution control in Lake Baiyangdian following water replenishment
AU - Hao, Peixian
AU - Yang, Jing
AU - Liu, Xia
AU - Strokal, Maryna
AU - van Wijk, Dianneke
AU - Bai, Zhaohai
AU - Ma, Lin
PY - 2024/12
Y1 - 2024/12
N2 - Eutrophication is an ecological process showing the state shift of a lake. This shift could be triggered when the external nitrogen (N) loads exceed N thresholds. Meanwhile, external water inputs and the resulting changes in lake water depth could affect N thresholds. Thus, the shift towards eutrophication may occur more quickly when the N thresholds decrease. Lake Baiyangdian is located in the North China Plain and plays an essential role in ecosystem service provision. However, this lake may have seen a decrease in the N threshold decrease due to frequent water replenishment since 2015. In this study, we compared the external N loads to Lake Baiyangdian with the N thresholds from 2012 to 2017. For this, we considered the effects of water replenishment by linking the MARINA-Lakes and the PCLake + models. Then, we assessed how N thresholds could be met by external N loads from sub-basins of Lake Baiyangdian under 2017 and different N management cases, including improved crop yield and efficiency (S1), improved sewage treatment (S2), improved manure management (S3), and combined options (S4). Results indicate that a 45% reduction in river export of N to Lake Baiyangdian was found from 2012 to 2017. Agricultural sources (fertilizer and manure) accounted for 59% of river exports of N in 2017. River N exports to the lake are projected to be reduced by 13–67% under the four cases. In 2017, the N-load response curve exhibited hysteresis with a 56–87% decrease in N thresholds compared to 2012. Measures in S4 can help to reduce external N exports to Lake Baiyangdian below the N thresholds. Our study emphasizes the importance of combined N management strategies to mitigate the eutrophication risk of the lake. These results offer valuable insights for N management in lake basins experiencing increasing water depth resulting from water replenishment.
AB - Eutrophication is an ecological process showing the state shift of a lake. This shift could be triggered when the external nitrogen (N) loads exceed N thresholds. Meanwhile, external water inputs and the resulting changes in lake water depth could affect N thresholds. Thus, the shift towards eutrophication may occur more quickly when the N thresholds decrease. Lake Baiyangdian is located in the North China Plain and plays an essential role in ecosystem service provision. However, this lake may have seen a decrease in the N threshold decrease due to frequent water replenishment since 2015. In this study, we compared the external N loads to Lake Baiyangdian with the N thresholds from 2012 to 2017. For this, we considered the effects of water replenishment by linking the MARINA-Lakes and the PCLake + models. Then, we assessed how N thresholds could be met by external N loads from sub-basins of Lake Baiyangdian under 2017 and different N management cases, including improved crop yield and efficiency (S1), improved sewage treatment (S2), improved manure management (S3), and combined options (S4). Results indicate that a 45% reduction in river export of N to Lake Baiyangdian was found from 2012 to 2017. Agricultural sources (fertilizer and manure) accounted for 59% of river exports of N in 2017. River N exports to the lake are projected to be reduced by 13–67% under the four cases. In 2017, the N-load response curve exhibited hysteresis with a 56–87% decrease in N thresholds compared to 2012. Measures in S4 can help to reduce external N exports to Lake Baiyangdian below the N thresholds. Our study emphasizes the importance of combined N management strategies to mitigate the eutrophication risk of the lake. These results offer valuable insights for N management in lake basins experiencing increasing water depth resulting from water replenishment.
KW - Baiyangdian
KW - Basin N management
KW - Nitrogen threshold
KW - Water replenishment
U2 - 10.1016/j.jenvman.2024.123374
DO - 10.1016/j.jenvman.2024.123374
M3 - Article
AN - SCOPUS:85209647432
SN - 0301-4797
VL - 372
JO - Journal of Environmental Management
JF - Journal of Environmental Management
M1 - 123374
ER -