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 CitationGeophysical Research Letters 38 (2011): L11402
Showing items related by title, author, creator and subject.
Geochemical and physical sources of radon variation in a subterranean estuary — implications for groundwater radon activities in submarine groundwater discharge studies Dulaiova, Henrieta; Gonneea, Meagan E.; Henderson, Paul B.; Charette, Matthew A. (2007-12-13)Submarine groundwater discharge (SGD), in form of springs and diffuse seepage, has long been recognized as a source of chemical constituents to the coastal ocean. Because groundwater is two to four orders of magnitude ...
A radiocarbon method and multi-tracer approach to quantifying groundwater discharge to coastal waters Gramling, Carolyn M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2003-09)Groundwater discharge into estuaries and the coastal ocean is an important mechanism for the transport of dissolved chemical species to coastal waters. Because many dissolved species are present in groundwater in ...
Observations of nearshore groundwater discharge : Kahekili Beach Park submarine springs, Maui, Hawaii Swarzenski, Peter W.; Dulai, Henrietta; Kroeger, Kevin D.; Smith, Christopher G.; Dimova, Natasha T.; Storlazzi, Curt D.; Prouty, Nancy G.; Gingerich, Stephen B.; Glenn, Craig R. (Elsevier, 2016-01-14)The study region encompasses the nearshore, coastal waters off west Maui, Hawaii. Here abundant groundwater—that carries with it a strong land-based fingerprint—discharges into the coastal waters and over a coral reef. ...