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, M.; MARTINEZ D.E.; MASSONE H.E.; LONDOÑO C.L.; DAPEÑA, C.

ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2015 vol. 53 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 catchment within the inter-mountainous Pampa Plain, Argentina. Geostatistical tools were used to define the model that best fit the spatial distribution of each tracer and obtained information in areas with lack of data. The conventional isotopic analysis allowed identifying three groundwater groups with different isotopic fingerprints. One group containing 56% of the total groundwater samples suggests a well-mixed system and rainfall as the main recharge source to the aquifer. The other groups include samples with a lighter and enriched isotopic content, 25.5 and 18.5 %, respectively. The combination of δ18O, δ2H and electrical conductivities maps suggest ascending regional flows and water transfer from the Quequén Grande River catchment to the Moro creek. The spatial interpretation of these tracers modifies the conceptual hydrogeological model of Quequén Grande River.