Unforeseen nitrate accumulation under nutrient mitigation measures in the east Pearl River Estuary: Phenomenon, drivers and implications

Wang，Linlin1,3; Lei，Xiaoyu2; Zhou，Yang1; Mao，Xian zhong2; Han，Jing Cheng1; Li，Bing2; Huang，Yuefei2,3,4; Zhao，Runqi2; Bi，Hongsheng5; Tang，Zhaozhao1; Wang，Yongqiang6; Li，Hailong7

2023-12-01

10.1016/j.ejrh.2023.101554

Journal of Hydrology: Regional Studies   影响因子和分区

2214-5818

Study region: Shenzhen Bay (SZB) in the east Pearl River Estuary, China Study focus: Either NO or NH is the dominant component of dissolved inorganic nitrogen (DIN) in most estuarine waters, but few studies focused on the mechanisms of ongoing DIN transformations under various hydrologic regimes. This analysis spans 31 years of DIN component changes and involves numerical simulations to identify the roles of various driving factors including runoff and biogeochemical actions. These new insights into DIN change mechanisms from the coupling biogeochemical and hydrodynamic processes would help to boost effective mitigation measures to deal with nitrate accumulation in estuarine waters, thereby supporting integrated land-ocean nutrient management. New hydrological insights for the region: The dominant DIN component in the SZB was found to transition from NH to NO between 1990 and 2020. Particularly in the -upper bay, there was an unexpected increase in the mean concentration fraction of NO in DIN, rising from 19.5% (1990-2017) to 65.5% (2018-2020). This change can be partially attributed to reduced runoff NH inputs. Both runoff and tidal current can transport NH and NOdownstream, but the high background levels of NO in the lower bay contributed to sustaining NO in the upper bay through ebb and flow. Biogeochemical actions further strengthened the decline of NH and the rise of NO. Even in scenarios without terrestrial source inputs, the simulated biogeochemical processes continued to help reduce NH levels throughout the bay while increasing NO concentrations in the middle and lower bay.

Estuary and runoff Hydrologic regime Nitrate accumulation Numerical simulation Nutrient mitigation

SCI

英语

其他

WOS:001109810300001

2-s2.0-85174703991

Scopus

1.Water Science and Environmental Engineering Research Center,College of Chemical and Environmental Engineering,Shenzhen University,Shenzhen,518060,China
2.Tsinghua Shenzhen International Graduate School,Tsinghua University,Shenzhen,518055,China
3.State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing,100084,China
4.State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining,810016,China
5.University of Maryland Center for Environmental Science,Chesapeake Bay Laboratory,Solomons,20688,United States
6.Changjiang River Scientific Research Institute,Wuhan,430010,China
7.State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control,School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Wang，Linlin,Lei，Xiaoyu,Zhou，Yang,et al. Unforeseen nitrate accumulation under nutrient mitigation measures in the east Pearl River Estuary: Phenomenon, drivers and implications[J]. Journal of Hydrology: Regional Studies,2023,50.

Wang，Linlin.,Lei，Xiaoyu.,Zhou，Yang.,Mao，Xian zhong.,Han，Jing Cheng.,...&Li，Hailong.(2023).Unforeseen nitrate accumulation under nutrient mitigation measures in the east Pearl River Estuary: Phenomenon, drivers and implications.Journal of Hydrology: Regional Studies,50.

Wang，Linlin,et al."Unforeseen nitrate accumulation under nutrient mitigation measures in the east Pearl River Estuary: Phenomenon, drivers and implications".Journal of Hydrology: Regional Studies 50(2023).