scholarly journals Modeling Nitrate-contaminated Groundwater Discharge to the Ria Formosa Coastal Lagoon (Algarve, Portugal)

2017 ◽  
Vol 17 ◽  
pp. 650-653 ◽  
Author(s):  
Rui Hugman ◽  
Tibor Stigter ◽  
Luis Costa ◽  
José Paulo Monteiro
Keyword(s):  
Coastal Lagoon ◽  
Groundwater Discharge ◽  
Contaminated Groundwater ◽  
Ria Formosa

Groundwater discharge rates and uncertainties in a coastal lagoon using a radon mass balance

2021 ◽  
pp. 126436
Author(s):  
Katie M. Coluccio ◽  
Isaac R. Santos ◽  
Luke C. Jeffrey ◽  
Leanne K. Morgan
Keyword(s):  
Mass Balance ◽  
Coastal Lagoon ◽  
Groundwater Discharge ◽  
Discharge Rates

scholarly journals Assessing land–ocean connectivity via submarine groundwater discharge (SGD) in the Ria Formosa Lagoon (Portugal): combining radon measurements and stable isotope hydrology

2016 ◽  
Vol 20 (8) ◽  
pp. 3077-3098 ◽  
Author(s):  
Carlos Rocha ◽  
Cristina Veiga-Pires ◽  
Jan Scholten ◽  
Kay Knoeller ◽  
Darren R. Gröcke ◽  
...  
Keyword(s):  
Submarine Groundwater Discharge ◽  
Large Fraction ◽  
Groundwater Discharge ◽  
Point Sources ◽  
Total N ◽  
Ria Formosa ◽  
Basin Scale ◽  
Wide Range ◽  
Dominant Feature ◽  
Submarine Groundwater

Abstract. Natural radioactive tracer-based assessments of basin-scale submarine groundwater discharge (SGD) are well developed. However, SGD takes place in different modes and the flow and discharge mechanisms involved occur over a wide range of spatial and temporal scales. Quantifying SGD while discriminating its source functions therefore remains a major challenge. However, correctly identifying both the fluid source and composition is critical. When multiple sources of the tracer of interest are present, failure to adequately discriminate between them leads to inaccurate attribution and the resulting uncertainties will affect the reliability of SGD solute loading estimates. This lack of reliability then extends to the closure of local biogeochemical budgets, confusing measures aiming to mitigate pollution.Here, we report a multi-tracer study to identify the sources of SGD, distinguish its component parts and elucidate the mechanisms of their dispersion throughout the Ria Formosa – a seasonally hypersaline lagoon in Portugal. We combine radon budgets that determine the total SGD (meteoric + recirculated seawater) in the system with stable isotopes in water (δ2H, δ18O), to specifically identify SGD source functions and characterize active hydrological pathways in the catchment. Using this approach, SGD in the Ria Formosa could be separated into two modes, a net meteoric water input and another involving no net water transfer, i.e., originating in lagoon water re-circulated through permeable sediments. The former SGD mode is present occasionally on a multi-annual timescale, while the latter is a dominant feature of the system. In the absence of meteoric SGD inputs, seawater recirculation through beach sediments occurs at a rate of  ∼  1.4  ×  106 m3 day−1. This implies that the entire tidal-averaged volume of the lagoon is filtered through local sandy sediments within 100 days ( ∼  3.5 times a year), driving an estimated nitrogen (N) load of  ∼  350 Ton N yr−1 into the system as NO3−. Land-borne SGD could add a further  ∼  61 Ton N yr−1 to the lagoon. The former source is autochthonous, continuous and responsible for a large fraction (59 %) of the estimated total N inputs into the system via non-point sources, while the latter is an occasional allochthonous source capable of driving new production in the system.

Nutrients and particulate matter exchanges through the Ria Formosa coastal lagoon, Portugal

2013 ◽  
Vol 165 ◽  
pp. 1999-2004 ◽  
Author(s):  
Alexandra Cravo ◽  
Sara Cardeira ◽  
Catarina Pereira ◽  
Mónica Rosa ◽  
Miguel Madureira ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Coastal Lagoon ◽  
Ria Formosa
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