Analysis of future nitrogen and phosphorus loading in watershed and the risk of lake blooms under the influence of complex factors: Implications for management

Zhen Wei; Yanxin Yu; Yujun Yi

doi:10.1016/j.jenvman.2023.118662

Analysis of future nitrogen and phosphorus loading in watershed and the risk of lake blooms under the influence of complex factors: Implications for management

J Environ Manage. 2023 Nov 1:345:118662. doi: 10.1016/j.jenvman.2023.118662. Epub 2023 Jul 20.

Authors

Zhen Wei¹, Yanxin Yu², Yujun Yi³

Affiliations

¹ School of Environment, Beijing Normal University, Beijing, 100875, China; Key Laboratory for Water and Sediment Science, Ministry of Education, Beijing Normal University, Beijing, 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: wz_water@sina.com.
² School of Environment, Beijing Normal University, Beijing, 100875, China; Key Laboratory for Water and Sediment Science, Ministry of Education, Beijing Normal University, Beijing, 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: yuhe_f@sina.com.
³ School of Environment, Beijing Normal University, Beijing, 100875, China; Key Laboratory for Water and Sediment Science, Ministry of Education, Beijing Normal University, Beijing, 100875, China; State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, 100875, China. Electronic address: yiyujun@bnu.edu.cn.

PMID: 37480666
DOI: 10.1016/j.jenvman.2023.118662

Abstract

For the management of eutrophic lakes, watershed nitrogen and phosphorus control is oriented to future water quality. Assessing future nutrient dynamics and the risk of lake eutrophication is necessary. However, current assessments often lack integrated consideration of socioeconomic and climatic factors, which reduces the reference value of the results. In this study, a typical large shallow lake Chaohu, which is highly influenced by human activities, was selected as the study area, and the current and future total nitrogen (TN) and total phosphorus (TP) loading in the basin were analysed using the improved MARINA model, and the risk of water bloom were assessed. The results showed that socioeconomic factors alone varied future TN and TP loading by -24% to 32% and -40% to 34%, respectively, under different development patterns. After considering the effect of increased precipitation, the changes of TN and TP loading became -10% to 163% and -29% to 108%, respectively. The effect on loading reduction under the sustainable development pattern was weakened (58% and 28% for TN and TP loading, respectively) and the increase in loading under the brutal development pattern was significantly amplified (409% and 215% for TN and TP loading, respectively). The adoption of active environmental policies remained an effective way of loading control. However, the risk of water bloom in local lake areas might persist due to factors such as urbanization. Timely and comprehensive assessments can provide managers with more information to identify key factors that contribute to the risk of water blooms and to develop diverse water quality improvement measures. The insights from our study are applicable to other watersheds around the world with similar socio-economic background and climatic conditions.

Keywords: ATAF; Eutrophication; Nutrient loading; SSPs; Shallow lake; Threshold.

MeSH terms

Environmental Policy*
Eutrophication
Fabaceae*
Humans
Nitrogen
Phosphorus

Substances

Nitrogen
Phosphorus