Hydro-chemical Characteristics of Melt Water Draining from Glaciers of Rongdo Basin, Shyok Valley, Ladakh

Physico-chemical parameters of meltwater of 20 water samples from glaciers of Rongdo basin, Shyok valley are presented here. The concentration of cations and anions of the two valleys were found in the order Ca>Mg>Na>K and HCO 3 >SO 4 >Cl>NO 3 respectively. Significant altitudinal variation was found in major ions as indicated by the increase of TDS of glacial melt and stream water samples downstream. Gibbs plot shows chemical weathering of the rock forming minerals as the main cause for contributing ions to the melt water. The dominant order of hydrogeochemical water types identified is Ca-HCO 3 , is due to the water rock interaction which leads to the easy dissolution of carbonate and silicate minerals. However, few glacial melt and stream water have the influence of precipitation and meltwater runoff on chemistry. The hot spring falls in Na-HCO 3 type, a typical of deeper groundwater influenced by ion exchange processes. Scatter plots of HCO 3 +SO 4 vs. Ca/Na Plot and Ca/Na vs. HCO 3 /Na clearly indicates that the weathering of carbonate and silicate play a dominant role on groundwater chemistry. Two chloro-alkaline indices indicate reverse exchange reaction between Na + , K + , Mg 2+ and Ca 2+ . The physical parameters and major ions are within the permissible concentrations as per WHO and BIS indicating water is good for drinking and domestic purposes. The groundwater is suitable for irrigation as per the quality parameters and plots including EC, sodium percent (Na%) and sodium adsorption ratio (SAR).