Articles | Volume 20, issue 8
https://doi.org/10.5194/hess-20-3077-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/hess-20-3077-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Assessing land–ocean connectivity via submarine groundwater discharge (SGD) in the Ria Formosa Lagoon (Portugal): combining radon measurements and stable isotope hydrology
Carlos Rocha
CORRESPONDING AUTHOR
Biogeochemistry Research Group, Geography Department, School of
Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
Cristina Veiga-Pires
Biogeochemistry Research Group, Geography Department, School of
Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
CIMA-Marine and Environmental Research Center, Universidade do
Algarve, Portugal
Jan Scholten
Institute of Geosciences, University of Kiel, Germany
Kay Knoeller
UFZ, Helmholtz Centre for Environmental Research Leipzig/Halle,
Germany
Darren R. Gröcke
Department of Earth Sciences, Durham University, South Road, Durham,
County Durham, DH1 3LE, UK
Liliana Carvalho
Biogeochemistry Research Group, Geography Department, School of
Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
CIMA-Marine and Environmental Research Center, Universidade do
Algarve, Portugal
Jaime Anibal
Biogeochemistry Research Group, Geography Department, School of
Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
CIMA-Marine and Environmental Research Center, Universidade do
Algarve, Portugal
Jean Wilson
Biogeochemistry Research Group, Geography Department, School of
Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
Related authors
No articles found.
Christina Franziska Radtke, Xiaoqiang Yang, Christin Müller, Jarno Rouhiainen, Ralf Merz, Stefanie R. Lutz, Paolo Benettin, Hong Wei, and Kay Knöller
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-109, https://doi.org/10.5194/hess-2024-109, 2024
Preprint under review for HESS
Short summary
Short summary
Most studies assume no difference between transit times of water and nitrate, because nitrate is transported by water. With an 8-year high-frequency dataset of isotopic signatures of both, water and nitrate, and a transit time model, we show the temporal varying difference of nitrate and water transit times. This finding is highly relevant for applied future research related to nutrient dynamics in landscapes under anthropogenic forcing and for managing impacts of nitrate on aquatic ecosystems.
Michael Rode, Jörg Tittel, Frido Reinstorf, Michael Schubert, Kay Knöller, Benjamin Gilfedder, Florian Merensky-Pöhlein, and Andreas Musolff
Hydrol. Earth Syst. Sci., 27, 1261–1277, https://doi.org/10.5194/hess-27-1261-2023, https://doi.org/10.5194/hess-27-1261-2023, 2023
Short summary
Short summary
Agricultural catchments show elevated phosphorus (P) concentrations during summer low flow. In an agricultural stream, we found that phosphorus in groundwater was a major source of stream water phosphorus during low flow, and stream sediments derived from farmland are unlikely to have increased stream phosphorus concentrations during low water. We found no evidence that riparian wetlands contributed to soluble reactive (SR) P loads. Agricultural phosphorus was largely buffered in the soil zone.
Erin L. McClymont, Michael J. Bentley, Dominic A. Hodgson, Charlotte L. Spencer-Jones, Thomas Wardley, Martin D. West, Ian W. Croudace, Sonja Berg, Darren R. Gröcke, Gerhard Kuhn, Stewart S. R. Jamieson, Louise Sime, and Richard A. Phillips
Clim. Past, 18, 381–403, https://doi.org/10.5194/cp-18-381-2022, https://doi.org/10.5194/cp-18-381-2022, 2022
Short summary
Short summary
Sea ice is important for our climate system and for the unique ecosystems it supports. We present a novel way to understand past Antarctic sea-ice ecosystems: using the regurgitated stomach contents of snow petrels, which nest above the ice sheet but feed in the sea ice. During a time when sea ice was more extensive than today (24 000–30 000 years ago), we show that snow petrel diet had varying contributions of fish and krill, which we interpret to show changing sea-ice distribution.
Laia Comas-Bru, Sandy P. Harrison, Martin Werner, Kira Rehfeld, Nick Scroxton, Cristina Veiga-Pires, and SISAL working group members
Clim. Past, 15, 1557–1579, https://doi.org/10.5194/cp-15-1557-2019, https://doi.org/10.5194/cp-15-1557-2019, 2019
Short summary
Short summary
We use an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled climate model to provide a protocol for using speleothem isotopic data for model evaluation, including screening the observations and the optimum period for the modern observational baseline. We also illustrate techniques through which the absolute isotopic values during any time period could be used for model evaluation.
Nnenesi A. Kgabi, Eliot Atekwana, Johanna Ithindi, Martha Uugwanga, Kay Knoeller, Lebogang Motsei, Manny Mathuthu, Gideon Kalumbu, Hilma R. Amwele, and Rian Uusizi
Proc. IAHS, 378, 93–98, https://doi.org/10.5194/piahs-378-93-2018, https://doi.org/10.5194/piahs-378-93-2018, 2018
Short summary
Short summary
High salinity in the groundwater of Cuvelai-Etosha Basin is caused by the weathering of Kalahari sediments, not the evaporation of water on surface prior to groundwater recharge. Low salinity in the Kuiseb Basin derives from rapid recharge by unevaporated rain and limited weathering of the crystalline rocks. Thus, groundwater quality in the two Basins is controlled by water-rock interaction at the surface and in the groundwater aquifer.
Niels A. G. M. van Helmond, Appy Sluijs, Nina M. Papadomanolaki, A. Guy Plint, Darren R. Gröcke, Martin A. Pearce, James S. Eldrett, João Trabucho-Alexandre, Ireneusz Walaszczyk, Bas van de Schootbrugge, and Henk Brinkhuis
Biogeosciences, 13, 2859–2872, https://doi.org/10.5194/bg-13-2859-2016, https://doi.org/10.5194/bg-13-2859-2016, 2016
Short summary
Short summary
Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past.
Here we investigate the response of phytoplankton, the base of the marine food web, to a rapid cold spell, interrupting greenhouse conditions during the Cretaceous.
Related subject area
Subject: Coasts and Estuaries | Techniques and Approaches: Instruments and observation techniques
River plastic transport affected by tidal dynamics
Monitoring tidal hydrology in coastal wetlands with the “Mini Buoy”: applications for mangrove restoration
Combining resistivity and frequency domain electromagnetic methods to investigate submarine groundwater discharge in the littoral zone
Combining continuous spatial and temporal scales for SGD investigations using UAV-based thermal infrared measurements
Analysis of data characterizing tide and current fluxes in coastal basins
Can mussels be used as sentinel organisms for characterization of pollution in urban water systems?
Turbidity in the fluvial Gironde Estuary (southwest France) based on 10-year continuous monitoring: sensitivity to hydrological conditions
Flooding in river mouths: human caused or natural events? Five centuries of flooding events in the SW Netherlands, 1500–2000
Determining slack tide with a GPS receiver on an anchored buoy
Ground-penetrating radar insight into a coastal aquifer: the freshwater lens of Borkum Island
Seasonal stratification and property distributions in a tropical estuary (Cochin estuary, west coast, India)
Suspended sediment load in the tidal zone of an Indonesian river
Deepwater Horizon oil spill impacts on Alabama beaches
Monitoring water quality in estuarine environments: lessons from the MAGEST monitoring program in the Gironde fluvial-estuarine system
Louise J. Schreyers, Tim H. M. van Emmerik, Thanh-Khiet L. Bui, Khoa L. van Thi, Bart Vermeulen, Hong-Q. Nguyen, Nicholas Wallerstein, Remko Uijlenhoet, and Martine van der Ploeg
Hydrol. Earth Syst. Sci., 28, 589–610, https://doi.org/10.5194/hess-28-589-2024, https://doi.org/10.5194/hess-28-589-2024, 2024
Short summary
Short summary
River plastic emissions into the ocean are of global concern, but the transfer dynamics between fresh water and the marine environment remain poorly understood. We developed a simple Eulerian approach to estimate the net and total plastic transport in tidal rivers. Applied to the Saigon River, Vietnam, we found that net plastic transport amounted to less than one-third of total transport, highlighting the need to better integrate tidal dynamics in plastic transport and emission models.
Thorsten Balke, Alejandra Vovides, Christian Schwarz, Gail L. Chmura, Cai Ladd, and Mohammad Basyuni
Hydrol. Earth Syst. Sci., 25, 1229–1244, https://doi.org/10.5194/hess-25-1229-2021, https://doi.org/10.5194/hess-25-1229-2021, 2021
Short summary
Short summary
Restoration of intertidal wetlands such as mangroves and saltmarshes requires accurate local data on tidal flooding and current velocities. We present the application of a low-cost underwater float equipped with an acceleration data logger, the Mini Buoy, to monitor inundation and tidal currents in intertidal environments. We demonstrate how this tool can be directly applied in hydrological site suitability assessments prior to mangrove restoration in tropical SE Asia.
Marieke Paepen, Daan Hanssens, Philippe De Smedt, Kristine Walraevens, and Thomas Hermans
Hydrol. Earth Syst. Sci., 24, 3539–3555, https://doi.org/10.5194/hess-24-3539-2020, https://doi.org/10.5194/hess-24-3539-2020, 2020
Short summary
Short summary
Fresh groundwater can flow to oceans and seas, possibly adding nutrients and pollutants to coastal ecosystems. For the first time, three complementary (salinity-sensitive) geophysical methods are combined to delineate the outflow in a very dynamic coastal environment. This provides temporal and spatial information on the salt- and freshwater distribution on land, in the intertidal zone, and offshore and visualizes the fresh-groundwater discharge around the low-water line at De Westhoek, Belgium.
Ulf Mallast and Christian Siebert
Hydrol. Earth Syst. Sci., 23, 1375–1392, https://doi.org/10.5194/hess-23-1375-2019, https://doi.org/10.5194/hess-23-1375-2019, 2019
Short summary
Short summary
Submarine groundwater discharge is highly variable in spatial and temporal terms. With a novel approach using a hovering drone over a predefined location which recorded 670 surface temperatures images over a period of 167 s, we are able to (i) enhance focused SGD patterns otherwise camouflaged by strong lateral flow dynamics, (ii) show size variation of up to 155 % (focused SGD) and 600 % (diffuse SGD), and (iii) reveal short-term periodicity of the order of 20 to 78 s for diffuse SGD.
Elvira Armenio, Francesca De Serio, and Michele Mossa
Hydrol. Earth Syst. Sci., 21, 3441–3454, https://doi.org/10.5194/hess-21-3441-2017, https://doi.org/10.5194/hess-21-3441-2017, 2017
Short summary
Short summary
The paper aims to investigate current and tide correlation in a basin named Mar Piccolo, located in the inner part of the Ionian Sea. It is considered highly vulnerable, being exposed to urban and industrial discharges as well as to intense naval traffic. A continuous monitoring action of the principal hydrodynamic parameters could be a useful managing tool, considering that the diffusion and dispersions of polluting tracers is strictly connected to currents, tide, and waves propagation.
Elke S. Reichwaldt and Anas Ghadouani
Hydrol. Earth Syst. Sci., 20, 2679–2689, https://doi.org/10.5194/hess-20-2679-2016, https://doi.org/10.5194/hess-20-2679-2016, 2016
Short summary
Short summary
We assessed if nitrogen stable isotopes in mussels are a suitable indicator, capable of resolving spatial and temporal variability of nutrient pollution in an urban estuary. Our results highlight the value of using stable isotope analysis as an integrative tool to establish an understanding of local processes and pollution levels in theses urban aquatic systems. We suggest that mussels can become a robust tool for the detection of emerging anthropogenic pollutants of concern in urban water systems.
I. Jalón-Rojas, S. Schmidt, and A. Sottolichio
Hydrol. Earth Syst. Sci., 19, 2805–2819, https://doi.org/10.5194/hess-19-2805-2015, https://doi.org/10.5194/hess-19-2805-2015, 2015
Short summary
Short summary
This study aims to analyse for the first time suspended sediment dynamics in the fluvial Gironde through a unique set of a 10-year continuous turbidity record. We demonstrate the following: the interest of turbidity-discharge hysteresis loops to evaluate the presence of sediment depositions; the relationships between features of the turbidity maximum zone (TMZ) and river flow; and the definition of hydrological indicators of the persistence and concentration of the TMZ.
A. M. J. de Kraker
Hydrol. Earth Syst. Sci., 19, 2673–2684, https://doi.org/10.5194/hess-19-2673-2015, https://doi.org/10.5194/hess-19-2673-2015, 2015
Short summary
Short summary
Natural floodings caused by storm floods also have important human components determining how disastrous they could be.
Man-made floodings during warfare were only successful if natural conditions and factors were fully used.
Strategic floodings during the 16th-17th centuries dramatically changed landscapes, from which valueble lessons were learnt to perfect this strategy in the 18th and 19th centuries.
M. Valk, H. H. G. Savenije, C. C. J. M. Tiberius, and W. M. J. Luxemburg
Hydrol. Earth Syst. Sci., 18, 2599–2613, https://doi.org/10.5194/hess-18-2599-2014, https://doi.org/10.5194/hess-18-2599-2014, 2014
J. Igel, T. Günther, and M. Kuntzer
Hydrol. Earth Syst. Sci., 17, 519–531, https://doi.org/10.5194/hess-17-519-2013, https://doi.org/10.5194/hess-17-519-2013, 2013
A. Shivaprasad, J. Vinita, C. Revichandran, P. D. Reny, M. P. Deepak, K. R. Muraleedharan, and K. R. Naveen Kumar
Hydrol. Earth Syst. Sci., 17, 187–199, https://doi.org/10.5194/hess-17-187-2013, https://doi.org/10.5194/hess-17-187-2013, 2013
F. A. Buschman, A. J. F. Hoitink, S. M. de Jong, P. Hoekstra, H. Hidayat, and M. G. Sassi
Hydrol. Earth Syst. Sci., 16, 4191–4204, https://doi.org/10.5194/hess-16-4191-2012, https://doi.org/10.5194/hess-16-4191-2012, 2012
J. S. Hayworth, T. P. Clement, and J. F. Valentine
Hydrol. Earth Syst. Sci., 15, 3639–3649, https://doi.org/10.5194/hess-15-3639-2011, https://doi.org/10.5194/hess-15-3639-2011, 2011
H. Etcheber, S. Schmidt, A. Sottolichio, E. Maneux, G. Chabaux, J.-M. Escalier, H. Wennekes, H. Derriennic, M. Schmeltz, L. Quéméner, M. Repecaud, P. Woerther, and P. Castaing
Hydrol. Earth Syst. Sci., 15, 831–840, https://doi.org/10.5194/hess-15-831-2011, https://doi.org/10.5194/hess-15-831-2011, 2011
Cited articles
Almasri, M. N. and Kaluarachchi, J. J.: Assessment and management of long-term nitrate pollution of ground water in agriculture-dominated watersheds, J. Hydrol., 295, 225–245, 2004.
Almeida, C. and Silva, M. L.: Incidence of agriculture on water quality at Campina de Faro (south Portugal), in: Hidrogeologia-y-Recursos-Hidraulicos, Associacion Españolade Hidrologia Subterranea, Madrid, Spain, 12, 249–257, 1987.
Almeida, C. J., Mendonca, J. J. L., Jesus, M. R., and Gomes, A. J.: Sistemas aquiferos de Portugal Continental (Aquifer Systems of Continental Portugal), Instituto Nacional da Água, INAG, Lisbon, 2000.
Balouin, Y.: Les embouchures mésotidales (tidal inlets) et leur relation avec les littoraux adjacents, exemple de la Barra Nova, sud Portugal, PhD thesis, University of Bordeaux, Bordeaux, 2001.
Barnes, C. J. and Allison, G. B.: The distribution of deuterium and 18O in dry soils: 1. Theory, J. Hydrol., 60, 141–156, 1983.
Barnes, C. J. and Allison, G. B.: Tracing of water movement in the unsaturated zone using stable isotopes of hydrogen and oxygen, J. Hydrol., 100, 143–176, 1988.
Beck, A. J., Tsukamoto, Y., Ovar-Sanchez, A., Huerta-Diaz, M., Bokuniewicz, H. J., and Sañudo-Wilhelmy, S. A.: Importance of geochemical transformations in determining submarine groundwater discharge-derived trace metal and nutrient fluxes, Appl. Geochem., 22, 477–490, 2007.
Blanco, A. C., Watanabe, A., Nadaoka, K., Motooka, S., Herrera, E. C., and Yamamoto, T.: Estimation of nearshore groundwater discharge and its potential effects on a fringing coral reef, Mar. Pollut. Bull., 62, 770–785, 2011.
Blanton, J. O., Amft, J., Oey, L.-Y., and Lee, T. N.: Advection of momentum and buoyancy in a coastal frontal zone, J. Phys. Oceanogr., 19, 98–115, 1989.
Blanton, J. O., Werner, F., Kim, C., Atkinson, L., Lee, T., and Savidge, D.: Transport and fate of low-density water in a coastal frontal zone, Cont. Shelf. Res., 14, 401–427, 1994.
Bratton, J. F.: The three scales of submarine groundwater flow and discharge across passive continental margins, J. Geol., 118, 565–575, 2010.
Burnett, W. C. and Dulaiova, H.: Estimating the dynamics of groundwater input into the coastal zone via continuous radon-222 measurements, J. Environ. Radioactiv., 69, 21–35, 2003.
Burnett, W. C., Taniguchi, M., and Oberdorfer, J.: Measurement and significance of the direct discharge of groundwater into the coastal zone, J. Sea Res., 46, 109–116, 2001a.
Burnett, W. C., Kim, G., and Lane-Smith, D.: A continuous monitor for assessment of 222Rn in the coastal ocean, J. Radioanal. Nucl. Ch., 249, 167–172, 2001b.
Burnett, W. C., Bokuniewicz, H., Huettel, M., Moore, W. S., and Taniguchi, M.: Groundwater and pore water inputs to the coastal zone, Biogeochemistry, 66, 3–33, 2003.
Burnett, W. C., Aggarwal, P. K., Aureli, A., Bokuniewicz, H., Cable, J. E., Charette, M. A., Kontar, E., Krupa, S., Kulkarni, K. M., Loveless, A., Moore, W. S., Oberdorfer, J. A., Oliveira, J., Ozyurt, N., Povinec, P., Privitera, A. M., Rajar, R., Ramessur, R. T., Scholten, J., Stieglitz, T., Taniguchi, M., and Turner, J. V.: Quantifying submarine groundwater discharge in the coastal zone via multiple methods, Sci. Total Environ., 367, 498–543, 2006.
Burnett, W. C., Peterson, R., Moore, W. S., and de Oliveira, J.: Radon and radium isotopes as tracers of submarine groundwater discharge – results from the Ubatuba, Brazil SGD assessment intercomparison, Estuar. Coast. Shelf S., 76, 501–511, 2008.
Cable, J. E., Burnett, W. C., Chanton, J. P., and Weatherly, G. L.: Estimating groundwater discharge into the northeastern Gulf of Mexico using radon-222, Earth Planet. Sc. Lett., 144, 591–604, 1996.
Cable, J. E., Martin, J. B., Swarzenski, P. W., Lindenberg, M. K., and Steward, J.: Advection within shallow pore waters of a coastal lagoon, Florida, GroundWater, 42, 1011–1020, 2004.
Carpenter, S. R., Caraco, N. F., Correll, D. L., Howarth, R. W., Sharpley, A. N., and Smith, V. H.: Nonpoint pollution of surface waters with phosphorus and nitrogen, Ecol. Appl., 8, 559–568, 1998.
Carreira, P. M.: Mechanisms of Salinization of Coastal Aquifers in the Algarve, MSc thesis, ICEN/INETI, 143 pp., 1991.
Carreira, P. M., Araújo, M. F., and Nunes, D.: Isotopic composition of rain and water vapour samples from Lisbon region: characterization of monthly and daily events, in: Isotopic Composition of Precipitation in the Mediterranean Basin in Relation to Air Circulate Patterns and Climate, IAEA-TECDOC-1453, IAEA, Vienna, Austria, 141–156, 2005.
Celle-Jeanton, H., Travi, Y., and Blavoux, B.: Isotopic typology of the precipitation in the western Mediterranean region at three different time scales, Geophys. Res. Lett., 28, 1215–1218, 2001.
Charette, M. A. and Sholkovitz, E. R.: Trace element cycling in a subterranean estuary: Part 2. Geochemistry of the pore water, Geochim. Cosmochim. Ac., 70, 811–826, 2006.
Charette, M. A., Sholkovitz, E. R., and Hansel, C. M.: Trace element cycling in a subterranean estuary: Part 1. Geochemistry of the permeable sediments, Geochim. Cosmochim. Ac., 69, 2095–2109, 2005.
Church, T. M.: An underground route for the water cycle, Nature, 380, 579–580, 1996.
Clark, I. D. and Fritz, P.: Environmental Isotopes in Hydrogeology, CRC Press, Boca Raton, Florida, 1997.
Colbert, S. L. and Hammond, D. E.: Temporal and spatial variability of radium in the coastal ocean and its impact on computation of nearshore cross-shelf mixing rates, Cont. Shelf. Res., 27, 1477–1500, 2007.
Colbert, S. L. and Hammond, D. E.: Shoreline and seafloor fluxes of water and short-lived Ra isotopes to surface water of San Pedro Bay, CA, Mar. Chem., 108, 1–17, 2008.
Colbert, S. L., Hammond, D. E., and Berelson, W. M.: Radon-222 budget in Catalina Harbor, California: 1. Water mixing rates, Limnol. Oceanogr., 53, 651–658, 2008a.
Colbert, S. L., Berelson, W. M., and Hammond, D. E.: Radon-222 budget in Catalina Harbor, California: 2. Flow dynamics and residence time in a tidal beach, Limnol. Oceanogr., 53, 659–665, 2008b.
Corbett, D. R., Burnett, W. C., Cable, P. H., and Clark, S. B.: A multiple approach to the determination of radon fluxes from sediments, J. Radioanal. Nucl. Ch., 236, 247–253, 1998.
Craig, H.: Standard for reporting concentrations of deuterium and oxygen-18 in natural waters, Science, 133, 1833–1834, 1961a.
Craig, H.: Isotopic variations in meteoric waters, Science, 133, 1702–1703, 1961b.
Craig, H. and Gordon, L. I.: Deuterium and oxygen-18 variations in the ocean and the marine atmosphere, in: Proceedings of a Conference on Stable Isotopes in Oceanographic Studies and Paleotemperatures, Spoleto, Italy, edited by: Tongiorgi, E., 9–130, 1965.
Crusius, J., Koopmans, D., Bratton, J. F., Charette, M. A., Kroeger, K., Henderson, P., Ryckman, L., Halloran, K., and Colman, J. A.: Submarine groundwater discharge to a small estuary estimated from radon and salinity measurements and a box model, Biogeosciences, 2, 141–157, https://doi.org/10.5194/bg-2-141-2005, 2005.
Dansgaard, W.: Stable isotopes in precipitation, Tellus, 16, 436–468, 1964.
Dias, J. M. and Sousa, M. C.: Numerical modeling of Ria Formosa tidal dynamics, J. Coast. Res., 56, 1345–1349, 2009.
Edmunds, W. M.: Renewable and non-renewable groundwater in semi-arid and arid regions, in: Developments in Water Science, Vol. 50, edited by: Alsharhan, A. S. and Wood, W. W., Elsevier, Amsterdam, 265–280, 2003.
EM-DAT: The OFDA/CRED International Disaster Database, Université Catholique de Louvain, Brussels, Belgium, available at: www.emdat.be, last access: June 2013.
Engelen, G. B. and van Beers, P. H.: Groundwater systems in the eastern Algarve, Portugal, in: Developments in the Analysis of Groundwater Flow Systems, IAHS Red Book Series 163, edited by: Engelen, G. B. and Jones, G. P., UNESCO/IAHS, Wallingford, UK, 325–331, 1986.
Ferreira, J. G., Simas, T., Nobre, A., Silva, M. C., Shifferegger, K., and Lencart-Silva, J.: Identification of Sensitive Areas and Vulnerable Zones in Transitional and Coastal Portuguese Systems, Instituto da Água and Institute of Marine Research, 168 pp., available at: http://www.eutro.org/documents/NEEA Portugal.pdf (last access: 3 July 2015), 2003.
Finkl, C. W. and Krupa, S. L.: Environmental impacts of coastal-plain activities on sandy beach systems: hazards, perception and mitigation, J. Coast. Res., 35, 132–150, 2003.
Frot, E., van Wesemael, B., Vandenschrick, G., Souchez, R., and Benet, A. S.: Origin and type of rainfall for recharge of a karstic aquifer in the western Mediterranean: a case study from the Sierra de Gador–Campo de Dalias (southeast Spain), Hydrol. Process., 21, 359–368, 2007.
Gat, J. R.: Oxygen and hydrogen isotopes in the hydrologic cycle, Annu. Rev. Earth Pl. Sc., 24, 225–262, 1996.
Gat, J. R. and Carmi, I.: Evolution of the isotopic composition of atmospheric waters in the Mediterranean Sea area, J. Geophys. Res., 75, 3039–3048, 1970.
Gat, J. R., Bowser, C. J., and Kendall, C.: The contribution of evaporation from the Great Lakes to the continental atmosphere: estimate based on stable isotope data, Geophys. Res. Lett., 21, 557–560, 1994.
Gibson, J. J. and Edwards, T. W. D.: Regional water balance trends and evaporation–transpiration partitioning from a stable isotope survey of lakes in northern Canada, Global Biogeochem. Cy., 16, 10–11, 2002.
Gilfedder, B. S., Frei, S., Hofmann, H., and Cartwright, I.: Groundwater discharge to wetlands driven by storm and flood events: Quantification using continuous Radon-222 and electrical conductivity measurements and dynamic mass-balance modeling, Geochim. Cosmochim. Ac., 165, 161–177, 2015.
Gonneea, M. E., Morris, P. J., Dulaiova, H., and Charette, M. A.: New perspectives on radium behavior within a subterranean estuary, Mar. Chem., 109, 250–267, 2008.
Hampel, F. R.: The influence curve and its role in robust estimation, J. Am. Stat. Assoc., 69, 383–393, 1974.
Hancock, G. J. and Murray, A. S.: Source and distribution of dissolved radium in the Bega River Estuary, southeastern Australia, Earth Planet. Sc. Lett., 138, 145–155, 1996.
Hancock, G. J., Webster, I. T., Ford, P. W., and Moore, W. S.: Using Ra isotopes to examine transport processes controlling benthic fluxes into a shallow estuarine lagoon, Geochim. Cosmochim. Ac., 64, 3685–3699, 2000.
IAEA/WMO: Global Network of Isotopes in Precipitation, The GNIP Database, available at: http://www.iaea.org/water (last access: June 2014), 2013.
Ibánhez, J. S. P., Leote, C., and Rocha, C.: Porewater nitrate profiles in sandy sediments hosting submarine groundwater discharge described by an Advection–Dispersion-Reaction Model, Biogeochemistry, 103, 159–180, 2011.
Ibánhez, J. S. P., Leote, C., and Rocha, C.: Seasonal enhancement of Submarine Groundwater Discharge (SGD) – derived nitrate loading into the Ria Formosa coastal lagoon assessed by 1-D modeling of benthic NO3-profiles, Estuar. Coast. Shelf S., 132, 56–64, 2013.
IH: Instituto Hidrografico: Marés 81/82 Ria de Faro. Estudo das marés de oito estações da Ria de Faro, Rel. FT-MC 4/86, IH, Instituto Hidrografico, Lisbon, 1986.
Kjerfve, B.: Comparative oceanography of coastal lagoons, in: Estuarine Variability, edited by: Wolfe, D. A., Academic Press, New York, 63–81, 1986.
Kroeger, K. D., Swarzenski, P. W., Greenwood, W. J., and Reich, C.: Submarine groundwater discharge to Tampa Bay: nutrient fluxes and biogeochemistry of the coastal aquifer, Mar. Chem., 104, 85–97, 2007.
Kwon, E. Y., Kim, G., Primeau, F., Moore, W. S., Cho, H. M., DeVries, T., Sarmiento, J. L., Charette, M. A., and Cho, Y. K.: Global estimate of submarine groundwater discharge based on an observationally constrained radium isotope model, Geophys. Res. Lett., 41, 8438–8444, 2014.
Lee, D. R.: A device for measuring seepage flux in lakes and estuaries, Limnol. Oceanogr., 22, 140–147, 1977.
Leote, C., Ibánhez, J. S., and Rocha, C.: Submarine groundwater discharge as a nitrogen source to the Ria Formosa studied with seepage meters, Biogeochemistry, 88, 185–194, 2008.
Li, L., Barry, D. A., Stagnitti, F., and Parlange, J.-Y.: Submarine groundwater discharge and associated chemical input to a coastal sea, Water Resour. Res., 35, 3253–3259, 1999.
Lobo-Ferreira, J. P., Oliveira, M. M., Diamantino, C., and Leitão, T. E.: LNEC Contribution to D24: AR needs in Campina de Faro, Julho, LNEC, Lisbon, 6 pp., 2007.
Macintyre, S., Wanninkhof, R., and Chanton, J. P.: Trace gas exchange across the air–sea interface in freshwater and coastal marine environments, in: Biogenic Trace Gases: Measuring Emissions from Soil and Water, edited by: Matson, P. A. and Harris, R. C., Blackwell Science Ltd, Cambridge, MA, 52–97, 1995.
Martin, J. B., Cable, J. E., Swarzenski, P. W., and Lindenberg, M. K.: Enhanced submarine ground water discharge from mixing of pore water and estuarine water, Ground Water, 42, 1000–1010, 2004.
Michael, H. A., Lubetsky, J. S., and Harvey, C. F.: Characterizing submarine groundwater discharge: A seepage meter study in Waquoit Bay, Massachusetts. Geophys. Res. Lett., 30, 1297, 30-1–30-4, 2003
Michael, H. A., Mulligan, A. E., and Harvey, C. F.: Seasonal oscillations in water exchange between aquifers and the coastal ocean, Nature, 436, 1145–1148, 2005.
Monteiro, J. P. and Costa Manuel, S.: Dams groundwater modelling and water management at the regional scale in a coastal Meditrranean area (the southern Portugal Region – Algarve), Larhyss J., 3, 157–169, 2004.
Moore, W. S.: Large groundwater inputs to coastal waters revealed by 226Ra enrichments, Nature, 380, 612–614, 1996.
Moore, W. S.: The subterranean estuary: a reaction zone of ground water and seawater, Mar. Chem., 65, 111–125, 1999.
Moore, W. S.: Determining coastal mixing rates using radium isotopes, Cont. Shelf. Res., 20, 1993–2007, 2000.
Moore, W. S.: The role of submarine groundwater discharge in coastal biogeochemistry, J. Geochem. Explor., 88, 389–393, 2006.
Moore, W. S.: The effect of submarine groundwater discharge on the ocean, Annu. Rev. Mar. Sci., 2, 59–88, 2010.
Moore, W. S. and Arnold, R.: Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter, J. Geophys. Res.-Oceans, 101, 1321–1329, 1996.
Moore, W. S. and Church, T. M.: Submarine groundwater discharge, Nature, 382, 122, 1996.
Mulligan, A. E. and Charette, M. A.: Intercomparison of submarine groundwater discharge estimates from a sandy unconfined aquifer, J. Hydrol., 327, 411–425, 2006.
Munksgaard, N. C., Wurster, C. M., Bass, A., Zagorskis, I., and Bird, M. I.: First continuous shipboard δ18O and δD measurements in sea water by diffusion sampling – Cavity Ring-Down Spectrometry, Environ. Chem. Lett., 10, 301–307, 2012.
Pacheco, A., Ferreira, Ó., Williams, J. J., Garel, E., Vila-Concejo, A., and Dias, J. A.: Hydrodynamics and equilibrium of a multiple-inlet system, Mar. Geol., 274, 32–42, 2010.
Povinec, P. P., Bokuniewicz, H., Burnett, W. C., Cable, J., Charette, M., Comanducci, J.-F., Kontar, E. A., Moore, W. S., Oberdorfer, J. A., de Oliveira, J., Peterson, R., Stieglitz, T., and Taniguchi, M.: Isotope Tracing of Submarine Groundwater Discharge Offshore Ubatuba, Brazil: Results of the IAEA, UNESCO SGD Project, J. Environ. Radioact., 99, 1596–1610, 2008.
Prieto, C. and Destouni, G.: Is submarine groundwater discharge predictable?, Geophys. Res. Lett., 38, L01402, https://doi.org/10.1029/2010GL045621, 2010.
Robinson, C., Li, L., and Barry, D. A.: Effect of tidal forcing on a subterranean estuary, Adv. Water Resour., 30, 851–865, 2007.
Rocha, C., Ibanhez, J., and Leote, C.: Benthic nitrate biogeochemistry affected by tidal modulation of Submarine Groundwater Discharge (SGD) through a sandy beach face, Ria Formosa, southwestern Iberia, Mar. Chem., 115, 43–58, 2009.
Rodgers, P., Soulsby, C., Waldron, S., and Tetzlaff, D.: Using stable isotope tracers to assess hydrological flow paths, residence times and landscape influences in a nested mesoscale catchment, Hydrol. Earth Syst. Sci., 9, 139–155, https://doi.org/10.5194/hess-9-139-2005, 2005.
Rohling, E. J.: Progress in paleosalinity: overview and presentation of a new approach, Paleoceanography, 22, PA3215, https://doi.org/10.1029/2007PA001437, 2007.
Salles, P.: Hydrodynamic Controls on Multiple Tidal Inlet Persistence, PhD thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution Joint Program in Oceanography/Applied Ocean Sci. and Engineering, Boston, MA, 2001.
Santos, I. R., Burnett, W. C., Chanton, J., Dimova, N., and Peterson, R. N.: Land or ocean? Assessing the driving forces of submarine groundwater discharge at a coastal site in the Gulf of Mexico, J. Geophys. Res., 114, 1–11, 2009.
Santos, I. R., Eyre, B. D., and Huettel, M.: The driving forces of porewater and groundwater flow in permeable coastal sediments: a review, Estuar. Coast. Shelf S., 98, 1–15, 2012.
Schubert, M., Paschke, A., Lieberman, E., and Burnett, W. C.: Air–water partitioning of 222Rn and its dependence on water temperature and salinity, Environ. Sci. Technol., 46, 3905–3911, 2012.
Schubert, M., Knoeller, K., Rocha, C., and Einsiedl, F.: Evaluation and Source Attribution of Freshwater Contributions to Kinvarra Bay, Ireland, Using 222Rn, EC and Stable Isotopes as Natural Indicators, Environ. Monit. Assess., 187, 1–15, 2015.
Silva, A. V., Portugal, A., and Freitas, L.: Groundwater flow model and salinization of coastal aquifers between Faro and Fuseta, Comun. Ser. Geol. Portugal, 72, 71–87, 1986.
Slomp, C. P. and Van Cappellen, P.: Nutrient inputs to the coastal ocean through submarine groundwater discharge: controls and potential impact, J. Hydrol., 295, 64–86, 2004.
Spiteri, C., Slomp, C. P., Tuncay, K., and Meile, C.: Modeling biogeochemical processes in subterranean estuaries: effect of flow dynamics and redox conditions on submarine groundwater discharge of nutrients, Water Resour. Res., 44, 1–18, 2008.
Stieglitz, T. C., Cook, P. G., and Burnett, W. C.: Inferring coastal processes from regional-scale mapping of 222radon and salinity: examples from the Great Barrier Reef, Australia, J. Environ. Radioactiv., 101, 544–552, 2010.
Stigter, T. Y. and Monteiro, J. P.: Strategies for integrating alternative groundwater sources into the water supply system of the Algarve, Portugal, Water Asset Management International – IWA 01/2008, 4, 19–24, 2008.
Stigter, T. Y., Carvalho Dill, A. M. M., Ribeiro, L., and Reis, E.: Impact of the shift from groundwater to surface water irrigation on aquifer dynamics and hydrochemistry in a semi-arid region in the south of Portugal, Agr. Water Manage., 85, 121–132, 2006.
Swarzenski, P. W., Orem, W. H., McPherson, B. F., Baskaran, M., and Wan, Y.: Biogeochemical transport in the Loxahatchee River Estuary, Florida: the role of submarine groundwater discharge, Mar. Chem., 101, 248–265, 2006.
Taniguchi, M., Burnett, W. C., Smith, C. F., Paulsen, R. J., O'Rourke, D., Krupa, S. L., and Christoff, J. L.: Spatial and temporal distributions of Submarine Groundwater Discharge rates obtained from various types of seepage meters at a site in the Northeastern Gulf of Mexico, Biogeochemistry, 66, 35–53, 2003.
Tett, P., Gilpin, L., Svendsen, H., Erlandsson, C. P., Larsson, U., Kratzer, S., Fouilland, E., Janzen, C., Lee, J.-Y., Grenz, C., Newton, A., Ferreira, J. G., Fernandes, T., and Scory, S.: Eutrophication and some European waters of restricted exchange, Cont. Shelf. Res., 23, 1635–1671, 2003.
Turner, S. M., Malin, G., Nightingale, P. D., and Liss, P. S.: Seasonal variation of dimethyl sulphide in the North Sea and an assessment of fluxes to the atmosphere, Mar. Chem., 54, 245–262, 1996.
Vila-Concejo, A., Ferreira, Ó., Morris, B. D., Matias, A., and Dias, J. M. A.: Lessons from inlet relocation: examples from southern Portugal, Coast. Eng., 51, 967–990, 2004.
Webster, I. T., Hancock, G. J., and Murray, A. S.: Use of radium isotopes to examine pore-water exchange in an estuary, Limnol. Oceanogr., 39, 1917–1927, 1994.
Webster, I. T., Hancock, G. J., and Murray, A. S.: Modelling the effect of salinity on radium desorption from sediments, Geochim. Cosmochim. Ac., 59, 2469–2476, 1995.
Zektser, I. S. and Loaiciga, H. A.: Groundwater fluxes in the global hydrologic cycle: past, present and future, J. Hydrol., 144, 405–427, 1993.
Short summary
We combine radon and stable isotopes in water to determine total submarine groundwater discharge (SGD) in the Ria Formosa and discriminate its component modes. We show that tidal action filters the entire water volume in the lagoon through local beaches 3.5 times a year, driving an estimated 350Ton nitrogen/year into the system. Conversely, fresh groundwater is discharged into the lagoon only occasionally, adding ~ 61 Ton nitrogen/year, but is capable of driving new production in the system.
We combine radon and stable isotopes in water to determine total submarine groundwater discharge...