Basin-Scale Geochemical Assessment of Water Quality in the Ganges River during the Dry Season

Identification of sources and transport pathways heavy metals major ions is crucial for effective water quality monitoring, particularly in large river systems. The Ganges basin, the largest most populous basin India, remains poorly studied this regard. We conducted a basin-level analysis ions, metals, stable isotopes nitrate during pre-monsoon season to constrain quantify inorganic chemical composition its lean flow. Bedrock weathering, anthropogenic interferences, contribution through tributaries, surface water-groundwater interaction were identified as driver metal ion variability river. Heavy showed highest concentrations upper section river, whereas ionic loads variable middle. find significant impact tributaries on lower reaches. Isotopic dissolved suggested synthetic fertilizers industrial wastes main sources. that otherwise clean waters can show high ionic/metallic at isolated stretches (As: up 36 µg/L), suggesting frequent monitoring source region maintain quality. Except collected from Yamuna Kannauj middle stretch Alaknanda Rishikesh stretch, WQI acceptable sampled stations. These findings provide an insight into modifications their different sections needed mitigating site-specific pollution roadmap evaluating other rivers world.