Estimación de la descarga de agua subterránea en un río de montaña perturbado antrópicamente (Sierras Pampeanas).

CAMPODONICO, V.A.; PASQUINI, A.I.; LECOMTE KL; ALVAREZ, BRENDA Y.; GARCÍA, M. G.

Congreso; XII REUNION ARGENTINA DE GEOQUIMICA DE LA SUPERFICIE; 2025

The surface water - groundwater interactions in a small anthropically affected mountainwatershed (Salsipuedes River) in the Sierras Pampeanas (central Argentina) wereanalyzed and quantified by means of 222Rn mass balance modeling. Moreover, itsimplications in hydrochemistry and water quality were examined. Surface waters, springsand groundwater were sampled during the 2021–2022 hydrological year. The studiedwaters are alkaline and of the bicarbonate - calcium type, with no spatial or seasonalvariations. 222Rn modeling indicates that near the headwaters, the Salsipuedes Riverrecharges the aquifer, whereas downstream the river acts as a gaining stream. Anthropicinfluence is noticeable in nitrate concentrations, derived from domestic wastes and septictanks. The highest concentrations of these ions in surface waters are found in theurbanized area, where the river stretch corresponds to a gaining stream, reflecting thateven small amounts of groundwater inputs can alter the chemical composition of streams.