Spatial Heterogeneity of Groundwater Hydrochemistry, Quality, and Degradation Mechanisms in Hyperarid Endorheic Watersheds: Insights From the Qaidam Basin on Tibetan Plateau
Hydrochemical assessment reveals widespread groundwater degradation and elevated nitrogen health risks for infants, indicating agricultural and evaporative drivers.
Key Points
To systematically evaluate groundwater quality suitability, nitrogen-driven human health risks, and geochemical degradation mechanisms across an arid endorheic basin.
Assessed phreatic groundwater hydrochemistry and suitability using the Entropy Weight Water Quality Index across upstream to downstream zones.
Quantified non-carcinogenic human health risks associated with nitrogen contamination across multiple age groups.
Only 37.78% of evaluated groundwater meets criteria for human use (EWQI < 100), exhibiting severe deterioration from upstream mountains to downstream salt marsh plains.
Nitrite (NO2−) represents the dominant nitrogen hazard, with infants experiencing the highest health risk among all demographic groups.
Water degradation is driven primarily by intense evaporative concentration in salt marsh plains and nonpoint-source agricultural pollution in loess plains.