Aplicación de la hidrología isotópica en la gestión de las aguas transfronterizas: Conclusión del proyecto piloto en la Cuenca Transfronteriza Tierra de los Lípez (Proyecto de cooperación técnica BOL-7005 del Estado Plurinacional de Bolivia). Depósito Legal 4-1-637-2022 P.O.

Abstract

This publication presents the scientific results of the pilot study conducted in the Tierra de los Lípez Transboundary Basin, developed under the Technical Cooperation Project BOL-7005 of the Plurinational State of Bolivia and the International Atomic Energy Agency (IAEA). The study applies advanced isotope hydrology techniques to characterize groundwater dynamics in one of South America’s most arid high-altitude basins shared by Bolivia, Chile, and Argentina. The research integrates stable isotopes (δ¹⁸O, δ²H, δ¹³C), radioactive isotopes (³H, ¹⁴C, ²²²Rn), hydrochemistry, hydrogeology, lithology, geophysics, topography, and GIS analyses to reconstruct the hydrodynamic functioning of the transboundary aquifer system, particularly the Laguna Colorada sub-basin. The results provide evidence on recharge mechanisms, evaporation processes, groundwater residence times, mixing patterns between shallow and deep flow systems, and discharge pathways toward the endorheic depressions of the region. The publication also establishes a conceptual hydrogeological model of the Tierra de los Lípez Transboundary Aquifer, contributing baseline scientific information essential for transboundary water governance, early cooperative frameworks, and hydrodiplomacy between neighboring countries. This document was conceptualized, led, and written by Gabriela Patricia Flores Avilés (PhD), as part of the national scientific program on isotope hydrology implemented by the Bolivian Nuclear Energy Agency (ABEN). It represents one of the first comprehensive applications of nuclear techniques to transboundary aquifer assessment in Bolivia.