Operational Monitoring of Brine-Based Lithium Production Facilities Using Sentinel-2 Time-Series Imagery and Assessment of Potential Supply-Chain Applications: A Case Study of the Olaroz and Cauchari Salars, Argentina

Lithium demand is increasing with the expansion of electric vehicles and energy storage systems, making the operational status of production facilities and supply-chain stability increasingly important.Detailed operational information on production facilities is generally not disclosed, whereas large evaporation ponds used in brine-based lithium production remain exposed at the surface, enabling continuous observation using satellite imagery.This study analyzed changes in the operational states of final lithium evaporation ponds in the Olaroz and Cauchari areas of Argentina using Sentinel-2 time-series imagery.Time-series Normalized Difference Water Index (NDWI) was applied to identify brine filling, concentration, depletion, and re-filling, revealing pond-specific operational characteristics and repetitive cycles.Distinct depletion states were observed at Olaroz in March 2023 and February 2024, and brine refilling after depletion was identified in RGB imagery.A comparison of operational-state changes with publicly available production and shipment records indicated cases in which depletion was observed before reported production records.These findings suggest that satellite imagery can provide baseline information for interpreting operational status, production readiness, and lithium supply-chain monitoring.