title: The impact of an underground cut-off wall on nutrient dynamics in groundwater in the lower Wang River watershed, China.
abstract: Underground cut-off walls in coastal regions are mainly used to prevent saltwater intrusion, but their impact on nutrient dynamics in groundwater is not clear. In this study, a combined analysis of multiple isotopes ([Formula: see text]) and nitrogen and phosphorus concentrations is used in order to assess the impact of the underground cut-off walls on the nutrient dynamics in groundwater in the lower Wang River watershed, China. Compared with the nitrogen and phosphorus concentrations in groundwater downstream of the underground cut-off walls, high [Formula: see text] and total dissolved nitrogen concentrations and similar concentration levels of [Formula: see text] and total dissolved phosphorus are found in groundwater upstream of the underground cut-off walls. The isotopic data indicated the probable occurrence of denitrification and nitrification processes in groundwater upstream, whereas the fingerprint of these processes was not shown in groundwater downstream. The management of fertilizer application is critical to control nitrogen concentrations in groundwater restricted by the underground cut-off walls.
authors.affiliation: a Department of Water Conservancy Engineering , North China University of Water Conservancy and Electric Power , Zhengzhou , People's Republic of China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Kang
authors.affiliation: b Institute of Water and Environmental Research, Faculty of Infrastructure Engineering , Dalian University of Technology , Dalian , People's Republic of China.
authors.forename: Shiguo
authors.initials: S
authors.lastname: Xu
mesh_terms: D002681:China; D004784:Environmental Monitoring; D060587:Groundwater / Q000032:analysis*; D009566:Nitrates / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis*; D009587:Nitrogen Isotopes / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009566:Nitrates; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Groundwater; Wang River; hydrogen-2; isotope hydrology; multiple isotopes approach; nitrogen transformation process; nitrogen-15; oxygen-18; phosphorus; underground cut-off wall