Hydrogeochemical assessment and water quality of glacier-fed catchment of Chenab basin, Kishtwar Himalaya, Jammu and Kashmir, India.

Abstract

River basins are cohesive entities that engage with geological formations and human activity. The evaluation and examination of the water quality in the Chenab River basin is essential due to its substantial contribution towards the sustainability of its ecosystem. The aim is to investigate the variability in hydrogeochemical characteristics of the glacier-fed Chenab River catchment (consisting of 72 samples) in the Kishtwar district, Jammu and Kashmir, India. The physicochemical analysis shows the abundance of major cations and anions concentrations in the following orders: Ca²⁺ > Mg²⁺ > Na⁺ > K⁺ and HCO₃¯ > SO₄²¯ > Cl¯ > NO₃¯ > PO₄^3¯, respectively. Results derived from the ionic ratio and Gibbs diagrams suggest the geogenic weathering process as the main source controlling the surface water chemistry in the region with carbonate-dominant lithology. This is supported by the Piper plot as the geochemical composition of water in Chenab River and its tributaries varies with dominant facies including Ca²⁺-Mg²⁺-HCO₃¯, mixed Ca²⁺-Mg²⁺-SO₄²¯, and Ca²⁺-Mg²⁺-Cl¯. The significant variation in water facies results from factors such as climate, lithology, and human activity. The data structure was analyzed using PCA, which identified three components and accounted for 79.85% of the total variation. This suggests that the composition of the water is mainly determined by natural factors, with minor contributions from human activities. Pearson's correlation results indicate a statistically positive correlation among water parameters. The drinking water quality index ranges from excellent to very poor. Overall, 45.83% fall into the good class, 41.67% fall into the poor class, 9.72% fall into the excellent class, and 2.78% fall into the very poor class categories, implying cautious use for drinking in the downstream region. Irrigation indices indicate that most water samples are appropriate for agricultural use. Geographic Information Systems (GIS) were employed simultaneously to visually represent the spatial arrangement of water quality measures and other irrigation indices. Periodic evaluations should be conducted in the Chenab River basin to identify water contamination resulting from the rapid expansion of socio-economic infrastructure and tourism in the area.