HIDROQUÍMICA DEL AGUA SUBTERRÁNEA EN UN SECTOR DE LA PLANICIE CENTRAL DE LA PROVINCIA DE LA PAMPA

DALMASO, GABRIELA; DAPEÑA, CRISTINA; MARIÑO, EDUARDO

Calidad del Agua Subterranea

Editorial Científica Universitaria, UNCA

Lugar: San Fernando del Valle de Catamarca; Año: 2016; p. 77 - 84

The paper addresses the hydrochemical evolution of groundwater in an environment of plain, gently undulating, located in the NE of the province of La Pampa, and covering an area of 440 km2, (IGM) Leaf 3763-1-2 "Estancia La Estelita". For that purpose 20 wells were sampled. The physicochemical parameters pH, electrical conductivity, temperature and oxide reduction potential were measured "in situ"; subsequently in the laboratory, it was determined concentration of majority chemical species, total dissolved solids, total hardness, alkalinity, nitrate, nitrite, fluoride, arsenic, iron, boron, aluminum, silica and stable isotopes (2H and 18O). Physicochemical parameters analyzed denote water with slightly basic pH, moderately oxidant and exhibits significant variability in their chemical composition. Hydrochemical characterization indicates the predominance of sodium bicarbonate waters as subordinate sodium chloride and sulfated waters. The isotopic composition of groundwater is consistent with meteoric recharge and its variations are due to several factors such as evaporation previous to infiltration, evaporation from the unsaturated zone and selective recharge of some precipitation. Geochemical processes that determine the composition of groundwater is the dissolution of carbonate materials and cation exchange, according to thermodynamic calculations and the ionic relations used in this study