This study focuses on the isotopic characterization of cryospheric water and quantification of different components contributing to Alaknanda River (major tributary of the Ganges River system) at its place of origin near snout of the Satopanth Glacier. A detailed understanding of various sources/flow components contributing to the river is useful for water resource management under changing climate scenario and helpful in risk assessment due to natural hazards in the headwater catchments, Extensive fieldwork was conducted, and water samples were collected from the river, snow, glacial ice, rain, lakes, and supraglacial channels of Satopanth Glacier Basin during the ablation period of 2017 and analysed for δ¹⁸O, δ²H, and ³H along with electrical conductivity. The results helped to establish the spatio-temporal and altitudinal variability in isotopic signatures of rain, snow, and ice in Satopanth Glacier Basin. The altitudinal effect in δ¹⁸O of pre-monsoon and monsoon rainfall is −0.13‰ and −0.41‰ per 100 m rise in elevation, respectively. Snow samples show depleting isotopic trend with an altitude effect of −0.43‰ in δ¹⁸O per 100 m rise in altitude. However, snowpack samples show an enrichment with time indicating post-depositional isotopic fractionation. The contrasting isotopic gradient in debris covered and non-debris covered ice are −0.9‰ and +3.4‰ per 100 m rise in elevation, respectively. These results divulge the spatial as well as temporal variation in cryospheric waters and these variations are used to derive the isotopic signatures of snow melt, glacier melt, and rain water. The results of hydrograph separation show that the snow melt, ice melt and rain water contribute about 33%, 49% and 18% respectively, to the discharge of Alaknanda River during the ablation period. Tracer based hydrograph separation indicates that the snow melt contribution dominates in river discharge during the initial ablation period. River discharge is a mixture of snow melt, glacier melt and rain water during July and August, while there is a dominance of glacier melt during end of the ablation period. The results of the present study highlight the importance of accounting the spatial and temporal variability in tracer signatures of cryospheric water for quantifying the contributions of snow and ice melt in a river originating from glacerised area.

这项研究的重点是冰冻圈水的同位素特征，以及量化在其起源地靠近撒托潘斯冰川的阿拉克南达河（恒河系统的主要支流）的不同成分的数量。深入了解造成河流的各种水源/流量成分，有助于在气候变化情况下进行水资源管理，并有助于对源头流域的自然灾害造成的风险进行评估，开展了广泛的实地考察，并从河流中收集了水样，雪，冰川，雨水，湖泊和supraglacial Satopanth冰川盆地中的2017消融周期通道并分析δ ¹⁸ O，δ ² H，和³H以及电导率。这些结果有助于确定萨托潘斯冰川盆地雨，雪和冰的同位素特征的时空和高度变异性。在δ的海拔效果¹⁸的O-预季风和季风降雨量-0.13‰和每100μm-0.41‰上升抬高，分别。雪样本显示在δ消耗与-0.43‰的高程效应同位素趋势¹⁸O每升高100 m高度。然而，积雪样品显示随时间的富集，表明沉积后同位素分馏。碎片覆盖和非碎片覆盖的冰中，每增加100 m海拔，同位素的相对梯度分别为-0.9‰和+ 3.4‰。这些结果揭示了冰冻圈水域的空间和时间变化，这些变化可用于得出融雪，冰川融化和雨水的同位素特征。水文图分离结果表明，在消融期间，雪融水，冰融水和雨水分别对阿拉克南达河的排放量贡献了33％，49％和18％。基于示踪剂的水文图分离表明，在初始消融期间，融雪贡献在河流排放中占主导。河流排放物是融雪的混合物，在七月和八月，冰川融化和雨水融化，而在消融期结束时，冰川融化占主导地位。本研究的结果强调了在冰冻圈水的示踪剂特征中考虑时空变化的重要性，以量化源自冰川地区的河流中冰雪融化的贡献。