A research team from the University of Massachusetts Amherst, the University of Alaska-Anchorage, and Columbia University conducted a wide-ranging hydrological tracer analysis of the Dry Andes region in Chile, Argentina, and Bolivia. The region is home to the majority of the world’s lithium deposits, crucial for the green energy transition, but is also extremely sensitive to activities like mining that can disrupt water systems. The lack of a comprehensive understanding of how hydrological systems work in arid landscapes has hindered environmental regulators in managing the mining industry and transitioning towards a more sustainable future. The research, published in PLOS Water, aims to address this knowledge gap.
The study challenges the traditional assumption that water is homogenous and suggests that there are distinct components to the water budget in the Dry Andes. Research lead Brendan Moran explains that water in the region responds differently to environmental changes and human usage. Of particular importance is the role water plays in lithium extraction, as the element leaches into groundwater from volcanic ash layers when rain or snowmelt passes through. Differentiating between types of water, such as fresh surface water and briny lithium-rich water, is crucial for both ecological conservation and sustainable resource extraction practices.
The research team, including David Boutt and Lee Ann Munk, developed a method to trace the age and origin of water samples using tritium and isotopes like 18O and 2H. This allowed them to determine the relative age of the water and track its interactions with the landscape. By sampling water sources across the Dry Andes, the researchers discovered that old and young waters do not mix and behave differently. Deep, old groundwater sustains the hydrological system in the region, while contemporary surface water is more sensitive to climate change, storm cycles, and human activities like mining.
The findings have significant implications for water management in arid regions like the Dry Andes and beyond. Protecting conduits that channel fresh rainwater into critical lagoons and wetlands is essential. Managers must develop tailored approaches for managing young and old waters, as one-size-fits-all solutions will not work. The research also highlights the universality of these hydrological processes across arid regions globally, suggesting that water managers worldwide need to consider the age and source of their water and implement appropriate policies to support diverse hydrological cycles.
The study’s findings shed light on the fundamental importance of understanding water systems in arid environments for sustainable resource management and environmental conservation. By recognizing the unique characteristics of different types of water and their behaviors in the hydrological cycle, regulators can make informed decisions to protect valuable ecosystems while supporting essential industries like lithium mining. The research team’s work serves as a valuable contribution to the broader conversation around water management in arid regions and the need for context-specific strategies to ensure the long-term sustainability of water resources.
