Abstract
Environmental stable isotopes (δ18O, δ2H), tritium (3H) and carbon (14C and 13C), together with geochemical data were used in order to identify the origin of salinization in the Lower Sado aquifer (Portugal). Groundwater salinization occurs, which may reach values of several grams of total dissolved salts per liter and above permissible limits of drinking water. The source of this high mineralization could be: (a) seawater intrusion (ancient vs. modern); (b) brine dissolution at depth. Stable and environmental radioactive isotopes together with geochemical signatures of waters have provided an effective label for seawater and freshwater to enable tracing of seawater intrusion, as well as identifying other processes that may be responsible for water salinization, such as salt minerals dissolution and ion exchange processes. The apparent groundwater ages estimated for the Miocene aquifer present an average around 20 ka Before Present indicating the presence of paleowaters. However, in the northern part of the basin modern seawater intrusion seems to play the major role in the groundwater mineralization in the shallow aquifer, where the increase of salinization is not followed by a groundwater ageing increase.
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References
Astier JL (1979) Etude des resources em eaux souterraines de la péninsule de Setúbal—Portugal. Geophysique. Nouveaux résultats de la prospection électrique. UNDP—Unesco, Dir. Geral Serv. Hidraulicos
Bouchaou L, Michelot JL, Vengosh A, Hsissou Y, Qurtobi M, Gaye CB, Bullen TD, Zuppi GM (2008) Application of multiple isotopic and geochemical tracers for investigation of recharge, salinization, and residence time of water in the Souss-Massa aquifer, southwest of Morocco. J Hydrol 352:267–287
Carreira PM, Soares AMM, Silva MAM, Araguás-Araguás L, Rozanski K (1996) Application of environmental isotope methods in assessing groundwater dynamics of an intensively exploited coastal aquifer in Portugal. In: Isotopes in water resources management, IAEA, Vienna, vol 2, pp 45–58
Carreira PM, Marques JM, Nunes D (2014) Source of groundwater salinity in coastline aquifers based on environmental isotopes (Portugal): natural vs. human interference. A review and reinterpretation. Appl Geoch 41:163–175
Edmunds WM (2005) Groundwater as an archive of climatic and environmental change. In: Aggarwal PK, Gat JR, Froehlich KFO (eds) Isotopes in the water cycle. Past, present and future of a developing science. Springer, The Netherlands, pp 341–352
Edmunds WM, Droubi A (1998) Groundwater salinity and environmental change. Isotope techniques in the study of environmental change. IAEA, Vienna, pp 503–518
Gonfiantini R, Zuppi GM (2003) Carbon isotopic exchange rate of DIC in karst groundwater. Chem Geol 197:319–336
Jalali M (2007) Salinization of groundwater in arid and semi-arid zones: an example from Tajarak, Western Iran. Environ Geol 52:1133–1149
Pennisi M, Bianchini G, Muti A, Kloppmann W, Gonfiantini R (2006) Behaviour of boron and strontium isotopes in groundwater–aquifer interactions in Cornia Plain (Tuscany, Italy). Appl Geochem 21:1169–1183
Re V, Sacchi E (2017) Tackling the salinity-pollution nexus in coastal aquifers from arid regions using nitrate and boron isotopes. Environ Sci Pollut Res 24:1–15
Salem O, Visser JM, Deay M, Gonfiantini R (1980) Groundwater flow patterns in western Lybian Arab Jamahitiya evaluated from isotope data. In: Arid zone hydrology: investigations with isotope techniques. IAEA. Vienna, pp 165–179
Simões MMM (1998) Contribuição para o conhecimento hidrogeológico do cenozoico na Bacia do Baixo Tejo (Contribution to the hydrogeological knowledge of the Cenozoic in the Baixo Tejo Basin). Ph.D. dissertation, Faculdade de Ciências e Tecnologia (FCT), Universidade Nova de Lisboa (in portuguese)
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The C2TN/IST author gratefully acknowledge the FCT support through the UID/Multi/04349/2013 Project, and CERENA/IST author acknowledges the FCT support through the UID/ECI/04028/2013 Project.
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Carreira, P.M., Marques, J.M. (2018). Groundwater Salinity and Environmental Change Over the Last 20,000 Years: Isotopic Evidences in the Lower Sado Aquifer Recharge, Portugal. In: Calvache, M., Duque, C., Pulido-Velazquez, D. (eds) Groundwater and Global Change in the Western Mediterranean Area. Environmental Earth Sciences. Springer, Cham. https://doi.org/10.1007/978-3-319-69356-9_8
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