A detailed analytical study of major cations (Ca²⁺, Mg²⁺, Na⁺, K⁺) and anions (SO$^{2−}_{4}$, HCO$^{−}_{3}$, Cl⁻, NO$^{−}_{3}$) of meltwater draining from Gangotri Glacier was carried out to understand major ion chemistry and to get an insight into geochemical weathering processes controlling hydrochemistry of the glacier. In the meltwater, the abundance order of cations and anions varied as follows: Ca²⁺ > Mg²⁺ > K⁺ > Na⁺ and SO$^{2−}_{4}$ > HCO$^{−}_{3}$ < Cl⁻ > NO$^{−}_{3}$, respectively. Calcium and magnesium are dominant cations while sulphate and bicarbonate are dominant anions. Weathering of rocks is the dominant mechanism controlling the hydrochemistry of drainage basin. The relative high contribution of (Ca+Mg) to the total cations (TZ⁺), high (Ca+Mg)/(Na+K) ratio (2.63) and low (Na+K)/TZ⁺ ratio (0.29) indicate the dominance of carbonate weathering as a major source for dissolved ions in the glacier meltwater. Sulphide oxidation and carbonation are the main proton supplying geochemical reactions controlling the rock weathering in the study area. Statistical analysis was done to identify various factors controlling the dissolved ionic strength of Gangotri Glacier meltwater.

Glaciers are widely recognized as sensitive indicators for regional climate change. Very few studies have been conducted to investigate the long term deglaciation status in the Himalaya. In the present study, glaciers in the Beas basin, Himachal Pradesh, India were mapped by interpretation of various glaciomorphological features using the Landsat and IRS images. The mapping of 224 glaciers during the period 1972–2006 reveals that the glacier cover reduced from 419 to 371 km², witnessing approximately 11.6% deglaciation in the Beas basin. A higher rate of retreat of the glaciers was observed during 1989–2006 as compared to the retreat during 1972–1989. Also, the loss has been more prominent in the glaciers with an areal extent of 2–5 km². The number of glaciers increased from 224 to 236 due to fragmentation in this period. The average elevation of the ablation zone basin showed an upward shift from 3898 m (1972) to 4171 m (2006) which may be a consequence of a shift in Equilibrium Line Altitude (ELA) reflecting imbalance.