GEOQUÍMICA Y 222Rn COMO HERRAMIENTAS PARA ESTABLECER RELACIONES AGUA SUPERFICIAL-SUBTERRANEA EN EL ARROYO AJI (CBA., ARG

BECHER QUINODOZ, F. N; BLARASIN, M.; DUCOS, E. I.; PANARELLO, H.O.

Mar del Plata

Simposio; III Reunión Argentina de Geoquímica de la Superficie; 2014

Universidad Nacional de Mar del Plata

AbstractThe study area comprises the middle-low basin of the Ají stream. The objective of this workis to characterize the hydraulic/geochemical relationships between surface water andgroundwater, adding 222Rn measures to validate the model. The aquifer-stream relationships were effluent/influent, varying in space as a result of geomorphology and human actions. The stream water samples and those abstracted from adjacent wells exhibit the same geochemical type (sodium bicarbonate) due to induced recharge. Considering that the surface water flows in areas with different groundwater salinity (up to 10.000 μS/cm in the low basin), it was interpreted that surface water control the water mixture process, diluting the salts that enter from the aquifer, as a result of its high velocity. This point is validated by 222Rn and the numerical modeling which indicate a small contribution from the aquifer (2-4 %) in summer. The isotopic behavior of both hydrological systems indicate water mixtures.