Abstract
Radon has been used to determine groundwater velocity and groundwater discharge into wetlands at the southern downstream boundary of the Crau aquifer, southeastern France. This aquifer constitutes an important high-quality freshwater resource exploited for agriculture, industry and human consumption. An increase in salinity occurs close to the sea, highlighting the need to investigate the water balance and groundwater behavior. Darcy velocity was estimated using radon activities in well waters according to the Hamada “single-well method” (involving comparison with radon in groundwater in the aquifer itself). Measurements done at three depths (7, 15 and 21 m) provided velocity ranging from a few mm/day to more than 20 cm/day, with highest velocities observed at the 15-m depth. Resulting hydraulic conductivities agree with the known geology. Waters showing high radon activity and high salinity were found near the presumed shoreline at 3,000 years BP, highlighting the presence of ancient saltwater. Radon activity has also been measured in canals, rivers and ponds, to trace groundwater discharges and evaluate water balance. A model of the radon spatial evolution explains the observed radon activities. Groundwater discharge to surface water is low in pond waters (4 % of total inputs) but significant in canals (55 l/m2/day).
Résumé
Le radon a été utilisé pour déterminer les vitesses de flux et la décharge d’eau souterraine dans les zones humides en limite sud de l’aquifère de la Crau, sud-est de la France. Cet aquifère constitue une importante ressource en eau de bonne qualité exploitée pour l’agriculture, l’industrie et la consommation humaine. Une augmentation de la salinité prend place près de la mer, soulignant la nécessité d’améliorer les connaissances sur le bilan en eau et le comportement des eaux souterraines. La vitesse de Darcy a été estimée en utilisant l’activité en radon dans des forages, suivant la méthode de puits unique d’Hamada (impliquant une comparaison avec le radon des eaux souterraines dans l’aquifère lui-même). Les mesures ont été réalisées à trois profondeurs (7, 15 et 21 m) donnant des vitesses de l’ordre de quelques mm/jours à plus de 20 cm/jour, les vitesses les plus élevées étant observées à 15 m de profondeur. Les conductivités hydrauliques déduites sont en accord avec les informations géologiques connues. Les eaux montrant une activité en radon élevée et une forte salinité sont localisées près de la côte présumée il y à 3000 ans BP, soulignant la présence d’eau salée ancienne. L’activité en radon a également été mesurée dans les canaux, rivières et étangs afin de tracer les zones de décharges d’eau souterraine et évaluer le bilan en eau. Un modèle de la distribution spatiale du radon permet d’expliquer les activités en radon observées. La décharge des eaux souterraines vers les eaux de surface est faible au niveau des étangs (4 % des apports totaux) mais significative dans les canaux (55 l/j/m2).
Resumen
El radón se ha utilizado para determinar la velocidad del agua subterránea y la descarga de agua subterránea en zonas húmedas en el límite sur del acuífero Crau, en el sureste de Francia. Este acuífero constituye un importante recurso de agua dulce de alta calidad explotada para la agricultura, la industria y el consumo humano. Un aumento de la salinidad se produce cerca del mar, destacándose la necesidad de investigar el comportamiento del balance hídrico y del agua subterránea. La velocidad de Darcy se estimó mediante la actividad del radón en los pozos, de acuerdo con el “método de un solo pozo” de Hamada (que implica la comparación con el radón en el agua subterránea del acuífero en sí). Las mediciones hechas a tres profundidades (7, 15 y 21 m) proporcionaron velocidades que van desde pocos mm/día a más de 20 cm/día, con las velocidades más altas observadas en la profundidad de 15-m. La conductividad hidráulica resultante está de acuerdo con la geología conocida. Las aguas que muestren una alta actividad de radón y alta salinidad fueron encontradas cerca de la línea costa supuesta de 3000 años AP, destacando la presencia de agua salada antigua. La actividad del radón también se ha medido en canales, ríos y lagunas, para localizar las descargas de agua subterránea y evaluar el balance hídrico. Un modelo de la evolución espacial del radón explica las actividades de radón observadas. La descarga de agua subterránea al agua superficial es baja en el agua de la laguna (4 % del total de los ingresos) pero es significativa en los canales (55 l/m2/día).
摘要
用氡确定地下水流速和地下水排泄到法国东南部Crau含水层南部下游边界的湿地。这个含水层构成了重要的高水质淡水资源,用于农业、工业和人类消费。接近海的区域盐度增加,更加突出了进行水平衡和地下水状态调查的必要性。根据Hamada“单井法”(包括与含水层内的地下水中的氡比较),利用钻孔中的氡活动估算了达西速度。三个深度(7、15和21米)进行的测量得出的速度为几毫米/天到20多厘米/天,15米深度的速度最高。产生的水力传导率与已知的地质状况一致。在假定距今3,000年的海岸线附近发现氡的活动性很高和盐度很高的水,彰显出古海水的存在。在渠道、河流和池塘都测量了氡的活动性以查探地下水排泄及评估水平衡。氡空间演化模型解释了观测到的氡活动性。在池塘水体中地下水排泄到地表水的量很低(大约入水量的4%),但在渠道中地下水排泄到地表水中的量很大(55 l/m2/day)。
Resumo
Radônio tem sido usado para determinar a velocidade das águas subterrâneas e a descarga das águas subterrâneas dentro de áreas úmidas a jusante do limite sul do aquífero do Crau, sudeste da França. Este aqüífero constitui um importante recurso de águas doces de alta qualidade exploradas pela agricultura, indústria e consumo humano. Um aumento da salinidade ocorre perto do mar, destacando a necessidade de investigar o balanço hídrico e o comportamento das águas subterrâneas. A velocidade de Darcy foi estimada usando as atividades do radônio em poços, de acordo com o “método de poço único” de Hamada (envolvendo comparação com radônio nas águas subterrâneas do aquífero em si). Medições feitas em três profundidades (7, 15 e 21 m) forneceram velocidades variando de poucos mm/dia a mais de 20 cm/dia, com maiores velocidades observadas a 15-m de profundidade. As condutividades hidráulicas resultantes concordam com a geologia conhecida. Águas mostrando alta atividade de radônio e alta salinidade foram encontradas perto da costa presumida a 3000 anos AP, destacando a presença de águas salgadas antigas. Atividade de radônio também tem sido medida em canais, rios e lagoas, para traçar descargas das águas subterrâneas e avaliar o balanço hídrico. Um modelo de evolução espacial de radônio explica a atividade de radônio observada. Descarga de águas subterrâneas para águas de superfície é baixa em águas da lagoa (4 % das entradas totais), mas significante em canais (55 l/m2/dia).
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References
Boyer J, Duvail C, Le Strat P, Gensous B, Tesson M (2005) High resolution stratigraphy and evolution of the Rhône delta plain during Postglacial time, from subsurface drilling data bank. Mar Geol 222–223:267–298
BRGM (1995) MARTCRAU: actualisation du modele de la nappe de la Crau [Update of the Crau aquifer model]. Report 94-D-211, BRGM, Orléans, France, 73 pp
BRGM (2015) Dossiers sur le sous-sol (BSS) [Records on the basement (BSS)]. http://infoterre.brgm.fr/dossiers-sur-le-sous-sol-bss. Accessed Oct 2015
Cockenpot S, Claude C, Radakovitch O (2015) Estimation of air-water gas exchange coefficient in a shallow lagoon based on 222Rn mass balance. J Environ Radioact. doi:10.1016/jjenvrad.2015.02.007
Cook PG, Love AJ, Dighton JC (1999) Inferring ground water flow in fractured rock from dissolved radon. Ground Water 37(4):606–610
De Montety V, Radakovitch O, Vallet-Coulomb C, Blavoux B, Hermitte D, Valles V (2008) Origin of groundwater salinity and hydrogeochemical processes in a confined coastal aquifer: case of the Rhône delta (southern France). Appl Geochem 23(8):2337–2349
Dimova N, Burnett WC, Lane-Smith D (2009) Improvements in the automated analyses of radon (222Rn) and thoron (220Rn) in water. Environ Sci Technol 43(22):8599–8603
Dimova NT, Burnett WC, Chanton JP, Corbett JE (2013) Application of radon-222 to investigate groundwater discharge into small shallow lakes. J Hydrol 486:112–122
Dulaiova H, Peterson R, Burnett WC, Lane-Smith D (2005) A multi-detector continuous monitor for assessment of Rn-222 in the coastal ocean. J Radioanal Nucl Chem 263:361–365
GIZCAM (2009) Constraints, limits and perspectives for integrated coastal zone management in the Rhone River delta. Liteau 2 final report, Tour du Valat, Arles, France
Graves B (ed) (1987) Radon, Radium and Other Radioactivity in Groundwater. Lewis Publishers,Chelesea, Michigan
Hamada H (2000) Estimation of groundwater flow rate using the decay of Rn-222 in a well. J Environ Radioact 47:1–13
Harris SA, Billmeyer ER, Robinson MA (2006) Evaluation of repeated measurements of radon-222 concentrations in well water sampled from bedrock aquifers of the Piedmont near Richmond, Virginia, USA: effects of lithology and well characteristics. Environ Res 101:323–333
Holman IP, Allen DM, Cuthbert MO, Goderniaux P (2012) Towards best practice for assessing the impacts of climate change on groundwater. Hydrogeol J 20:1–4
INRA (2013) Sustainable use of irrigation water in the Mediterranean region. Report D5.3, SIRRIMED. http://www.sirrimed.org/catalogo/d4_4_d4_5_model_adaptation_coupling_v03.pdf. Accessed Oct 2015
Kasztovszky Z, Sajo-Bohus L, Fazekas B (2000) Parametric changes of radon (222Rn) concentration in ground water in northeastern Hungary. J Environ Radioact 49:171–180
Lazar B, Weinstein Y, Paytan A, Magal E, Bruce D, Kolodny K (2008) Ra and Th adsorption coefficients in lakes: Lake Kinneret (Sea of Galilee) “natural experiment”. Geochim Cosmochim Acta 72(14–72):3446–3459
MacIntyre S, Wanninkhof R, Chanton JP (1995). Trace gas exchange across the air-sea interface in freshwater and coastal marine environments. In: Matson PA, Harriss C (eds) Methods in ecology - Biogenic trace gases: measuring emissions from soil and water. Blackwell Science, Oxford, pp 52–97
Molliex S, Siame LL, Bourlès DL, Bellier O, Braucher R, Clauzon G (2013) Quaternary evolution of a large alluvial fan in a periglacial setting (Crau Plain, SE France) constrained by terrestrial cosmogenic nuclide (10Be). Geomorphology 195:45–52
Mullinger NJ, Pates JM, Binley AM, Crook NP (2009) Controls on the spatial and temporal variability of 222Rn in riparian groundwater in a lowland Chalk catchment. J Hydrol 376:58–69
Olioso A, Lecerf R, Baillieux A, Chanzy A, Ruget F, Banton O, Lecharpentier P, Trolard F, Cognard-Plancq A-L (2013) Modelling of drainage and hay production over the Crau aquifer for analysing impact of global change on aquifer recharge. Procedia Environ Sci 19:691–700
Peng TH, Akatashi TT, Broecker WS (1974) Surface radon measurements in the north Pacific Ocean Station Papa. J Geophys Res 79:1772–1780. doi:10.1029/JC079i012p01772
Radakovitch O, Mayer A, Garcia Orellana J, Garcia Solsona E, Claude C, Masque Barri P, Chauvelon P, Ollivier P (2007) Submarine groundwater discharge estimates on coastal waters based on 222Rn measurements. Proceedings of 38th CIESM Congress, Istanbul, April 2007, 698 pp
Radakovitch O, Mayer A, Chauvelon P, Vallet-Coulomb C, Claude C, Parisot JC, Hermitte D (2009) Groundwater inputs in the Vaccares lagoon (South France) estimated from 222Rn budget. ECOCLR: 4th European Congress on Lagoon Research, Montpellier, France, December 2009
Rodellas V, Garcia-Orellana J, Garcia-Solsona E, Masqué P, Domínguez JA, Ballesteros BJ, Mejías M, Zarroca M (2012) Quantifying groundwater discharge from different sources into a Mediterranean wetland by using 222Rn and Ra isotopes. J Hydrol 466–467:11–12
Roure S, Duvail C, Aunay B, Le Strait P (2004) Geodynamique des Systemes Plio-quaternaires des Nappes Alluviales de la Plaine de la Crau [Geodynamic of the Plio Quaternary systems of the Alluvial sediments of the Crau plain]. BRGM report, RP-53088-RR, BRGM, Orléans, France
Schubert M, Brueggemann L, Knoeller K, Schirmer M (2011) Using radon as an environmental tracer for estimating groundwater flow velocities in single-well tests. Water Resour Res 47(3). doi:10.1029/2010WR009572
Seeton CJ (2006) Viscosity–temperature correlation for liquids. Tribol Lett 22:67–78. doi:10.1007/s11249-006-9071-2
Shi H, Singh A (2003) Status and interconnections of selected environmental issues in the global coastal zones. AMBIO 32(2):145–152. doi:10.1579/0044-7447
Stieglitz TC, van Beek P, Souhaut M, Cook PG (2013) Karstic groundwater discharge and seawater recirculation through sediments in shallow coastal Mediterranean lagoons, determined from water, salt and radon budgets. Mar Chem 156:73–84
Vella C, Fleury TJ, Raccasi G, Provensal M, Sabatier F, Bouricier M (2005) Evolution of the Rhone delta plain in the Holocene. Mar Geol 222–223:235–265
Werner AD, Bakker M, Post VEA, Vandenbohede A, Lu C, Ataie-Ashtiani B, Simmons CT, Barry DA (2013) Seawater intrusion processes, investigation and management: recent advances and future challenges. Adv Water Resour 51:3–26
Acknowledgements
This work has been supported by the Ministry of Training and Education of France and Vietnam (French-Vietnamese cooperation). We thank ‘Grand Port de Marseille’ and ‘Syndicat Mixte de Gestion de la Nappe Phréatique de la Crau’ for data provided and ‘Reserve Naturelle des Marais du Vigueirat’ for access to sites.
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Mayer, A., Nguyen, B.T. & Banton, O. Using radon-222 to study coastal groundwater/surface-water interaction in the Crau coastal aquifer (southeastern France). Hydrogeol J 24, 1775–1789 (2016). https://doi.org/10.1007/s10040-016-1424-9
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DOI: https://doi.org/10.1007/s10040-016-1424-9