Nutrient dynamics and discharge in a coastal sandy beach aquifer

It is of great significance to understand the behavior of nutrients in the groundwater seawater mixing zone (GSMZ) and quantify the input of terrestrial nutrients into the sea. This study focuses on the coastal sandy beach of Beijin Bay, Guangdong Province. Based on the stratified sampling and analy...

Full description

Saved in:
Bibliographic Details
Main Authors: Xuejing WANG, Yifan GUO, Shengchao YU, Qianqian WANG, Hailong LI, Chunmiao ZHENG
Format: Article
Language:zho
Published: Editorial Office of Hydrogeology & Engineering Geology 2025-01-01
Series:Shuiwen dizhi gongcheng dizhi
Subjects:
Online Access:https://www.swdzgcdz.com/en/article/doi/10.16030/j.cnki.issn.1000-3665.202409063
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1841524908173033472
author Xuejing WANG
Yifan GUO
Shengchao YU
Qianqian WANG
Hailong LI
Chunmiao ZHENG
author_facet Xuejing WANG
Yifan GUO
Shengchao YU
Qianqian WANG
Hailong LI
Chunmiao ZHENG
author_sort Xuejing WANG
collection DOAJ
description It is of great significance to understand the behavior of nutrients in the groundwater seawater mixing zone (GSMZ) and quantify the input of terrestrial nutrients into the sea. This study focuses on the coastal sandy beach of Beijin Bay, Guangdong Province. Based on the stratified sampling and analysis of the hydrochemical composition of coastal groundwater, this study investigated the distribution characteristics, migration, and transformation of nutrients in coastal groundwater.The submarine groundwater discharge (SGD) and associated nutrient flux into the sea were also evaluated, exploring the potential environmental impacts on coastal water. The results show that compared with surface water, coastal groundwater had higher nutrient content. The concentrations of nitrate and nitrite (\begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document}), phosphate (\begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document}) and silicate (Si) in groundwater gradually decreased from land to sea and from shallow layer to deep layer. Non-conservative removal of \begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document} and \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document} occurred after passing through the GSMZ. \begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document} was mainly removed by denitrification reaction, with the concentration decreasing by 95.81% from land to sea, while \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document} was mainly removed primarily by the adsorption to iron oxide/hydroxide end products. A hotspot of ammonia nitrogen (\begin{document}$ {\mathrm{N}\mathrm{H}}_{4}^{+} $\end{document}) was generated in the middle of the aquifer, and non-conservative addition of \begin{document}$ {\mathrm{N}\mathrm{H}}_{4}^{+} $\end{document} occurred, mainly due to the decomposition and release of organic matter. The estimated SGD rate was 1.49×106 m3/d, comparable to local river discharge. SGD-derived nutrients were estimated to be 983.0 kg/d for dissolved inorganic nitrogen (DIN), 37.00 kg/d for \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document}, and 4023 kg/d for Si, making SGD a a significant source of nutrients to coastal waters. In addition, groundwater had a high ratio of nitrogen to phosphorus (mean:139.6) and ratio of silicon to phosphorus (mean:274.1), while the ratios in seawater were 21.03 and 33.12, respectively. SGD with high ratio of nitrogen to phosphorus had important impacts on the nutrient structure of coastal seawater. Sandy beaches are widely distributed, and the findings of this study can provide scientific basis for the management of ecological environment in similar areas.
format Article
id doaj-art-8ca20c9ea03a4f68905a6cbb6b28bd9d
institution Kabale University
issn 1000-3665
language zho
publishDate 2025-01-01
publisher Editorial Office of Hydrogeology & Engineering Geology
record_format Article
series Shuiwen dizhi gongcheng dizhi
spelling doaj-art-8ca20c9ea03a4f68905a6cbb6b28bd9d2025-01-18T03:52:24ZzhoEditorial Office of Hydrogeology & Engineering GeologyShuiwen dizhi gongcheng dizhi1000-36652025-01-01521122210.16030/j.cnki.issn.1000-3665.202409063202409063Nutrient dynamics and discharge in a coastal sandy beach aquiferXuejing WANG0Yifan GUO1Shengchao YU2Qianqian WANG3Hailong LI4Chunmiao ZHENG5School of Earth System Science, Tianjin University, Tianjin 300072, ChinaSchool of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, ChinaSchool of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, ChinaState Key Laboratory of Estuaries and Coastal Research (East China Normal University), Shanghai 200241, ChinaSchool of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, ChinaSchool of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, ChinaIt is of great significance to understand the behavior of nutrients in the groundwater seawater mixing zone (GSMZ) and quantify the input of terrestrial nutrients into the sea. This study focuses on the coastal sandy beach of Beijin Bay, Guangdong Province. Based on the stratified sampling and analysis of the hydrochemical composition of coastal groundwater, this study investigated the distribution characteristics, migration, and transformation of nutrients in coastal groundwater.The submarine groundwater discharge (SGD) and associated nutrient flux into the sea were also evaluated, exploring the potential environmental impacts on coastal water. The results show that compared with surface water, coastal groundwater had higher nutrient content. The concentrations of nitrate and nitrite (\begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document}), phosphate (\begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document}) and silicate (Si) in groundwater gradually decreased from land to sea and from shallow layer to deep layer. Non-conservative removal of \begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document} and \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document} occurred after passing through the GSMZ. \begin{document}$ {\mathrm{N}\mathrm{O}}_{{x}}^{-} $\end{document} was mainly removed by denitrification reaction, with the concentration decreasing by 95.81% from land to sea, while \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document} was mainly removed primarily by the adsorption to iron oxide/hydroxide end products. A hotspot of ammonia nitrogen (\begin{document}$ {\mathrm{N}\mathrm{H}}_{4}^{+} $\end{document}) was generated in the middle of the aquifer, and non-conservative addition of \begin{document}$ {\mathrm{N}\mathrm{H}}_{4}^{+} $\end{document} occurred, mainly due to the decomposition and release of organic matter. The estimated SGD rate was 1.49×106 m3/d, comparable to local river discharge. SGD-derived nutrients were estimated to be 983.0 kg/d for dissolved inorganic nitrogen (DIN), 37.00 kg/d for \begin{document}$ {\mathrm{P}\mathrm{O}}_{4}^{3-} $\end{document}, and 4023 kg/d for Si, making SGD a a significant source of nutrients to coastal waters. In addition, groundwater had a high ratio of nitrogen to phosphorus (mean:139.6) and ratio of silicon to phosphorus (mean:274.1), while the ratios in seawater were 21.03 and 33.12, respectively. SGD with high ratio of nitrogen to phosphorus had important impacts on the nutrient structure of coastal seawater. Sandy beaches are widely distributed, and the findings of this study can provide scientific basis for the management of ecological environment in similar areas.https://www.swdzgcdz.com/en/article/doi/10.16030/j.cnki.issn.1000-3665.202409063sandy aquifercoastal groundwater mixing zonenutrientssubmarine groundwater discharge (sgd)beijin bay
spellingShingle Xuejing WANG
Yifan GUO
Shengchao YU
Qianqian WANG
Hailong LI
Chunmiao ZHENG
Nutrient dynamics and discharge in a coastal sandy beach aquifer
Shuiwen dizhi gongcheng dizhi
sandy aquifer
coastal groundwater mixing zone
nutrients
submarine groundwater discharge (sgd)
beijin bay
title Nutrient dynamics and discharge in a coastal sandy beach aquifer
title_full Nutrient dynamics and discharge in a coastal sandy beach aquifer
title_fullStr Nutrient dynamics and discharge in a coastal sandy beach aquifer
title_full_unstemmed Nutrient dynamics and discharge in a coastal sandy beach aquifer
title_short Nutrient dynamics and discharge in a coastal sandy beach aquifer
title_sort nutrient dynamics and discharge in a coastal sandy beach aquifer
topic sandy aquifer
coastal groundwater mixing zone
nutrients
submarine groundwater discharge (sgd)
beijin bay
url https://www.swdzgcdz.com/en/article/doi/10.16030/j.cnki.issn.1000-3665.202409063
work_keys_str_mv AT xuejingwang nutrientdynamicsanddischargeinacoastalsandybeachaquifer
AT yifanguo nutrientdynamicsanddischargeinacoastalsandybeachaquifer
AT shengchaoyu nutrientdynamicsanddischargeinacoastalsandybeachaquifer
AT qianqianwang nutrientdynamicsanddischargeinacoastalsandybeachaquifer
AT hailongli nutrientdynamicsanddischargeinacoastalsandybeachaquifer
AT chunmiaozheng nutrientdynamicsanddischargeinacoastalsandybeachaquifer