Assessing groundwater recharge in an Andean closed basin using isotopic characterization and a rainfall-runoff model: Salar del Huasco basin, Chile


Jorge Gironás


Hydrogeology Journal


Pontificia Universidad Católica de Chile


Ciencias de la Tierra


  1. Javier Uribe, Geohidrología Consultores Limitada-Arcadis Chile, Santiago, Chile. Departamento de Ingeniería Hidráulica y Ambiental Pontificia Universidad Católica de Chile, Santiago, Chile
  2. José F. Muñoz, Departamento de Ingeniería Hidráulica y Ambiental Pontificia Universidad Católica de Chile, Santiago, Chile
  3. Jorge Gironás, Departamento de Ingeniería Hidráulica y Ambiental Pontificia Universidad Católica de Chile, Santiago, Chile. Centro Interdisciplinario de Cambio Global Pontificia Universidad Católica de Chile, Santiago, Chile. Centro Nacional de Investigación para la Gestión Integrada de Desastres Naturales CONICYT/FONDAP/15110017, Santiago, Chile
  4. Ricardo Oyarzún, Departamento Ingeniería de Minas Universidad de La Serena, La Serena, Chile. Centro de Estudios Avanzados en Zona Áridas (CEAZA), La Serena, Chile
  5. Evelyn Aguirre, Laboratorio de Isótopos Ambientales, Comisión Chilena de Energía Nuclear, Santiago, Chile
  6. Ramón Aravena, Department of Earth and Environmental Sciences University of Waterloo, Waterloo, Canada


Closed basins are catchments whose drainage networks converge to lakes, salt flats or alluvial plains. Salt flats in the closed basins in arid northern Chile are extremely important ecological niches. The Salar del Huasco, one of these salt flats located in the high plateau (Altiplano), is a Ramsar site located in a national park and is composed of a wetland ecosystem rich in biodiversity. The proper management of the groundwater, which is essential for the wetland function, requires accurate estimates of recharge in the Salar del Huasco basin. This study quantifies the spatio-temporal distribution of the recharge, through combined use of isotopic characterization of the different components of the water cycle and a rainfall-runoff model. The use of both methodologies aids the understanding of hydrological behavior of the basin and enabled estimation of a long-term average recharge of 22 mm/yr (i.e., 15 % of the annual rainfall). Recharge has a high spatial variability, controlled by the geological and hydrometeorological characteristics of the basin, and a high interannual variability, with values ranging from 18 to 26 mm/yr. The isotopic approach allowed not only the definition of the conceptual model used in the hydrological model, but also eliminated the possibility of a hydrogeological connection between the aquifer of the Salar del Huasco basin and the aquifer that feeds the springs of the nearby town of Pica. This potential connection has been an issue of great interest to agriculture and tourism activities in the region.


Groundwater recharge, Stable isotopes, Closed basin, High plateau, Chile


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