Study of isotopic seasonality to assess the water source of proglacial stream in Chhota Shigri Glaciated Basin, Western Himalaya

Autor: Arindan Mandal, Naveen Kumar, Mohd Soheb, Shyam Ranjan, Aman Arora, Alagappan Ramanathan, Parmanand Sharma
Rok vydání: 2019
Předmět:
Zdroj: Hydrological Processes. 34:1285-1300
ISSN: 1099-1085
0885-6087
DOI: 10.1002/hyp.13676
Popis: The impact of surface melt patterns and the Indian summer monsoon (ISM) is examined on the varying contributions of end member (snow, glacier ice, and rain) to proglacial streamflow during the ablation period (June–October) in the Chhota Shigri glaciated basin, Western Himalaya. Isotopic seasonality observed in the catchment precipitation was generally reflected in surface runoff (supraglacial melt and proglacial stream) and shows a shift in major water source during the melt season. Isotopically correlated (δ¹⁸O–δD) high deuterium intercept in the surface runoff suggests that westerly precipitation acts as the dominant source, augmenting the other snow‐ and ice‐melt sources in the region. The endmember contributions to the proglacial stream were quantified using a three‐component mixing. Overall, glacier ice melt is the major source of proglacial discharge. Snowmelt is the predominant source during the early ablation season (June) and the peak ISM period (August and September), whereas ice melt reaches a maximum in the peak melt period (July). The monthly contribution of rain is on the lower side and shows a steady rise and decline with onset and retreat of the monsoon. These results are persistent with the surface melt pattern observed in Chhota Shigri glacier, Upper Chandra basin. Moreover, the role of the ISM in Chhota Shigri glacier is unvarying to that observed in other glacierized catchments of Upper Ganga basin. Thus, this study augments the significant role of the ISM in glacier mass balance up to the boundary of the central‐western Himalayan glaciated region.
Databáze: OpenAIRE
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