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TitreApplication of the tracer radon-222 to identify groundwater discharge hotspots along the Lake Simcoe shoreline
TéléchargerTéléchargement (publication entière)
AuteurRobinson, C; Wallace, H; Ji, T
SourceRegional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house; par Russell, H A J; Ford, D; Priebe, E H; Commission géologique du Canada, Dossier public 8212, 2017 p. 31, https://doi.org/10.4095/299798
Année2017
ÉditeurRessources naturelles Canada
RéunionOntario Geological Survey and Geological Survey of Canada groundwater geoscience open house; Guelph; CA; mars 1-2, 2017
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/299798
Mediaen ligne; numérique
Référence reliéeCette publication est contenue dans Russell, H A J; Ford, D; Priebe, E H; (2017). Regional-scale groundwater geoscience in southern Ontario: an Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario open house, Commission géologique du Canada, Dossier public 8212
Formatspdf
ProvinceOntario
SNRC31D/03; 31D/04; 31D/05; 31D/06; 31D/11; 31D/12
Lat/Long OENS -80.0000 -79.0000 44.7500 44.0000
Sujetseau souterraine; aquifères; ressources en eau souterraine; gestion des ressources; planification; résurgence des eaux souterraines; taux de décharge; eaux de surface; lacs; littoraux; etudes isotopiques; isotopes; radon; qualité de l'eau; substances polluantes; levés géochimiques; régimes des eaux souterraines; modèles; hydrogéologie; géochimie; géologie de l'environnement
Consultation
Endroit
 
Bibliothèque de Ressources naturelles Canada - Ottawa (Sciences de la Terre)
 
ProgrammeAquifer Assessment & support to mapping, Géoscience des eaux souterraines
Diffusé2017 02 22
Résumé(disponible en anglais seulement)
Groundwater discharge can be an important pathway for transporting pollutants, including nutrients, metals, and chloride into large inland lakes. Quantification of groundwater inputs into large lakes is often challenging due to high spatial variability in discharge patterns. While prior studies have identified offshore groundwater discharge locations (submarine hollows and vents) into Lake Simcoe, there is limited understanding of the magnitude of groundwater discharge to the lake including identification of areas that may be hotspots for discharge. The objective of this study was to evaluate the use of the natural tracer radon-222 (222Rn) for evaluating groundwater discharge along the shoreline of Lake Simcoe. 222Rn is a suitable tracer for quantifying groundwater discharge to inland lakes as its concentrations are typically 3-4 orders of magnitude higher in groundwater than in surface water. Regional scale 222Rn boat surveys were conducted along the shoreline of Lake Simcoe in summer 2015 and 2016 to identify potential groundwater discharge hotspots. Measurements were conducted using portable radon instrumentation (RAD 7 and RAD AQUA, Durridge Inc.). Groundwater discharge hotspots were located along the north shore of Kempenfelt Bay and along the south shore of Lake Simcoe. Regional-scale survey results were compared with hydrogeological studies previously conducted for subwatersheds around Lake Simcoe to gain understanding of the hydrogeological controls on the detected groundwater hotspot areas. High spatial resolution 222Rn surveys were also carried out in identified hotspot areas and a steady-state mass balance model which considers the various sources and sinks of 222Rn (e.g., air evasion, offshore mixing) was applied to estimate groundwater discharge rates. The challenge of applying a 222Rn mass balance is minimizing uncertainties associated with 222Rn loss through air evasion, as well as adequately characterizing 222Rn concentrations in the groundwater endmember. High resolution survey results confirmed high groundwater discharge in the hotspot areas with discharge highest near the shore and decreasing offshore. The development of regional-scale methods such as 222Rn for evaluating groundwater discharge to large inland waters including Lake Simcoe is critical for developing effective and targeted management plans aimed reducing the contribution of groundwater pollutants to degrading lake water quality.
GEOSCAN ID299798