Assessment of hydrological systems associated with groundwater discharges in arid high mountain environments of the Argentine Andes

Abstract

In arid high mountain regions, groundwater discharge in the form of springs is a vital water resource for rural people living in these remote areas. In this context, the aim of this study is to evaluate the processes that condition the hydrochemistry and isotopic signal of springs in hydrological systems associated with complex geological-structural environments in selected areas of Cordillera Frontal and Cordillera Principal in the Andean Region. A detailed geological study was carried out and spring water samples were taken for the determination of major ions and stable isotopes. The results obtained show that there are hydrochemical and isotopic differences between the studied areas. Hydrochemical facies are conditioned by the composition of the rocks through which the groundwater flow occurs before discharge. Isotopic differences are explained by different origins of moisture sources affected by the geo-structural features of the area. The groundwater of Cordillera Principal is isotopically depleted with a signal similar to that of the Pacific rains. Meanwhile, the more enriched groundwater in the Cordillera Frontal would be associated with rainfall contributions from the Atlantic. These isotopic differences provide evidence that the effects of climate change may affect these Andean regions differently.