A novel approach for direct estimation of fresh groundwater discharge to an estuary
Figure S1: Flood and ebb tide index velocity calibrations relating center-channel velocity with channel-average velocity. (1.246Mb)
Figure S3: Index salinity calibration relating depth-averaged, channel-edge salinity (index salinity) with channel-average salinity. (1.195Mb)
Ganju, Neil K.
MetadataShow full item record
Coastal groundwater discharge is an important source of freshwater and nutrients to coastal and estuarine systems. Directly quantifying the spatially integrated discharge of fresh groundwater over a coastline is difficult due to spatial variability and limited observational methods. In this study, I applied a novel approach to estimate net freshwater discharge from a groundwater-fed tidal creek over a spring-neap cycle, with high temporal resolution. Acoustic velocity instruments measured tidal water fluxes while other sensors measured vertical and lateral salinity to estimate cross-sectionally averaged salinity. These measurements were used in a time-dependent version of Knudsen's salt balance calculation to estimate the fresh groundwater contribution to the tidal creek. The time-series of fresh groundwater discharge shows the dependence of fresh groundwater discharge on tidal pumping, and the large difference between monthly mean discharge and instantaneous discharge over shorter timescales. The approach developed here can be implemented over timescales from days to years, in any size estuary with dominant groundwater inputs and well-defined cross-sections. The approach also directly links delivery of groundwater from the watershed with fluxes to the coastal environment.
This paper is not subject to U.S. copyright. The definitive version was published in Geophysical Research Letters 38 (2011): L11402, doi:10.1029/2011GL047718.
Suggested CitationArticle: Ganju, Neil K., "A novel approach for direct estimation of fresh groundwater discharge to an estuary", Geophysical Research Letters 38 (2011): L11402, DOI:10.1029/2011GL047718, https://hdl.handle.net/1912/4648
Showing items related by title, author, creator and subject.
The magnitude and origin of groundwater discharge to Eastern U.S. and Gulf of Mexico coastal waters Befus, Kevin Martin; Kroeger, Kevin D.; Smith, Christopher G.; Swarzenski, Peter W. (John Wiley & Sons, 2017-10-28)Fresh groundwater discharge to coastal environments contributes to the physical and chemical conditions of coastal waters, but the role of coastal groundwater at regional to continental scales remains poorly defined due ...
Russoniello, Christopher J.; Konikow, Leonard F.; Kroeger, Kevin D.; Fernandez, Cristina; Andres, A. Scott; Michael, Holly A. (2016-05-02)Submarine groundwater discharge (SGD) is a small portion of the global water budget, but a potentially large contributor to coastal nutrient budgets due to high concentrations relative to stream discharge. A numerical ...
Isotope tracing of submarine groundwater discharge offshore Ubatuba, Brazil : results of the IAEA–UNESCO SGD project Povinec, Pavel P.; Bokuniewicz, H. J.; Burnett, William C.; Cable, J.; Charette, Matthew A.; Comanducci, J.-F.; Konta, E. A.; Moore, Willard S.; Oberdorfer, J. A.; de Oliveira, J.; Peterson, R.; Stieglitz, T.; Taniguchi, M. (2008-06-12)Results of groundwater and seawater analyses for radioactive (3H, 222Rn, 223Ra, 224Ra, 226Ra, 228Ra) and stable (2H, 18O) isotopes are presented together with in situ spatial mapping and time-series 222Rn measurements in ...