Hydrogeochemical characteristics of the Indus river water system

Abstract

ABSTRACT The Indus River is the most prominent freshwater source of the northwestern part of the Indian subcontinent. Glacier/snow melting during the summer season is the main source of water. Here, we are presenting the major ion chemistry of the Indus river water, its tributary rivers, including small streams (nallahs), mainly in the territory of India, to know the overall quality of water, and geochemical processes controlling the solute acquisition and sources of elements in the catchment region. The analytical results indicate that the water samples are mildly acidic to alkaline in nature and have Ca2+ and Mg2+ dominance in cationic and HCO3 - and Cl- in anionic composition. Overall, alkaline-earth elements (Ca2+ + Mg2+) dominate over alkalis (Na+ + K+), and weak acids (HCO3 -) exceed strong acids (SO4 2- + Cl-) in the river/stream water samples. The hydrogeochemical diagrams, molar ratios, and statistical analysis suggest that carbonate and silicates minerals’ weathering mainly control the solute acquisition process with negligible contribution from marine or anthropogenic sources. Most of the surface water samples are fit for drinking and domestic uses except the hot spring and saline lake waters.