Application of Stable Isotopes of Water to Study Coupled Submarine Groundwater Discharge and Nutrient Delivery

摘要: Submarine groundwater discharge (SGD)—including terrestrial freshwater, density-driven flow at the saltwater–freshwater interface, and benthic exchange—can deliver nutrients to coastal areas, generating a negative effect in quality of marine water bodies. It is recognized that stable isotopes (18O 2H) can be helpful tracers identify different paths origins water. Here, we show they also applied when assessing sources areas. A field site near lagoon (Ringkobing Fjord, Denmark) has been monitored metric scale test if used achieve better understanding hydrochemical processes taking place aquifers, where there transition from freshwater saltwater. Results 18O 2H differentiate aquifer into three zones: Freshwater, shallow, deep saline zones, which corresponded well with zones having distinct concentrations inorganic phosphorous. The explanation associated mechanisms: (1) Differences sediment composition, (2) chemical reactions triggered by mixing type fluxes, (3) biochemical diffusive bed. behaviors Ringkobing Fjord need considered management. PO4 underneath exceeds concentration inland, thus demonstrating an intra-lagoon origin, while NO3, higher inland due anthropogenic activity, denitrified study area before reaching lagoon.