Delineating groundwater potential in arid closed basins under dual-constraints of water quantity and quality: An integrated LASSO regression and Geospatial-AHP approach

Bayin River watershed, a typical arid endorheic watershed on Qinghai-Xizang Plateau. Delineating groundwater potential zones remains a global challenge in arid endorheic watersheds, where groundwater availability is constrained by both quantity and quality. This study aims to identify zones with favorable groundwater quantity and quality and to elucidate the hydrological mechanisms governing their spatial differentiation in an arid closed basin. The integrated groundwater potential (IGP) of different geomorphic units in the Bayin River watershed shows pronounced spatial heterogeneity. High IGP is concentrated in the alluvial-proluvial plain, where thick and laterally continuous aquifers, strong river seepage, and irrigation return flow jointly enhance groundwater storage and renewal. In contrast, the proluvial plain exhibits moderate groundwater potential due to thin aquifers and the absence of stable recharge sources. The alluvial-lacustrine plain is characterized by low integrated potential despite relatively favorable storage conditions, owing to shallow groundwater depth, weak hydraulic gradients, intense evaporation, and agricultural activities that promote groundwater salinization. These results highlight the critical role of aquifer structure and geomorphic conditions in controlling both groundwater quantity and quality in arid endorheic basins. A conceptual model is developed to synthesize these subsurface hydrological processes, providing a hydrologically grounded framework to support groundwater source field selection, sustainable groundwater development, and ecological protection in arid regions. • Proposing integrated groundwater potential considering water quantity and quality. • LASSO regression performs exceptionally well in feature selection. • Subsurface hydrological processes dictate the groundwater potential zones. • Desalting high-saline groundwater rise resilience of arid cities to climate change.