Comprehensive assessment of the Torud Playa Basin hydrogeological reserves in NE Iran: Insights from utilizing pumping test methods

• Emphasizing the hydrogeological reserves of the Torud Playa. • Advanced pumping test methods to explore the water resources of the Torud Playa. • Prioritizing long-term management strategies for the region. • Accurate determination of water levels in the Torud Playa aquifer. • Ensuring sustainable groundwater usage and effective management in Torud Playa. The Torud Playa Basin in northeastern Iran possesses significant brine and hydrocarbon exploration potential. Its complex geology—comprising playa basins, evaporites, and multi-layered aquifers—presents unique challenges for pumping test implementation. The Torud Playa hydrogeological reserves were evaluated through multi-level pumping tests and hydrogeochemical analysis. These methods addressed the basin's complex evaporite geology. The study aims to understand reservoir behavior and develop effective management strategies, including improved water management practices and the identification of new exploration targets. The study's results have significantly contributed to understanding the reservoir behavior and developing effective management strategies. It is indicated that the studied area is divided into four sections, with poor permeability in the central parts (<1.5 m/day) and good permeability in the northern region (>3 m/day). This work identifies the north-northeastern parts of the Torud Playa suitable for potash reserves, with an estimated volume of 27,200.18 million cubic meters (Mm 3 ) solutes in the playa and salt crust and an excavated volume of 18,133.45 Mm 3 . Sustainable exploitation requires limiting extraction to 40-60% of static reserves (327-490 Mm³) to maintain hydrological balance, with 90% extraction causing 3.2 m water table decline and 62% habitat loss. These findings provide novel insights into reserve assessment methodologies for playa basins, integrating hydrodynamic and geochemical approaches to guide evidence-based resource management in arid regions.