Spatial distribution of Electrical Conductivity and Stable Isotopes in groundwater in large catchments: a geostatistical approach in the Quequén Grande River Catchment, Argentina.

QUIROZ LONDOÑO, MAURICIO; MARTINEZ, DANIEL E.; MASSONE, HECTOR; LONDOÑO CIRO, LIBARDO A.; DAPEÑA, CRISTINA

ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2015 vol. 51 p. 411 - 425

1025-6016

Stable isotopes and electrical conductivity in groundwater were used as natural tracers to adjust the hydrogeological conceptual model in one of the largest catchments within the inter-mountainous Pampa Plain, Argentina. Geostatistical tools were used to define the model that best fitted the spatial distribution of each tracer and information was obtained in areas where there was a lack of data. The conventional isotopic analysis allowed the identification of three groundwater groups with different isotopic fingerprints. One group containing 56 % of the total groundwater samples suggested a well-mixed system and soil infiltration precipitation as the main recharge source to the aquifer. The other groups included samples with a lighter or higher isotopic composition, 25.5 and 18.5 %, respectively. The combination of δ18O, δ2H and electrical conductivities maps suggested ascending regional flows and water transfer from the Quequén Grande River catchment to the Moro creek. The spatial interpretation of these tracers modified the conceptual hydrogeological model of Quequén Grande Rive