National Centre for Polar and Ocean Research (NCPOR), Ministry of Earth Sciences, Vasco-da-Gama, Goa 403804, India; School of Earth, Ocean, and Atmospheric Sciences, Goa University, Goa 403206, India.
National Centre for Polar and Ocean Research (NCPOR), Ministry of Earth Sciences, Vasco-da-Gama, Goa 403804, India.
Sci Total Environ. 2021 Aug 1;780:146500. doi: 10.1016/j.scitotenv.2021.146500. Epub 2021 Mar 17.
Melting of snow and glaciers from the high-altitude Himalayan region is a significant water source to the major Himalayan rivers, especially in the upper Indus Basin (UIB), which contributes up to 70% of river discharge. Considering Indus Basin as a largest irrigation system dependent on snow and glacier melt runoff, it is imperative to study the rivers' current status and water budget. In this study we have performed a tracer-based hydrograph separation to quantify the contribution of seasonal snow, glacier melt, and groundwater to the Chandra River draining from a semi-arid region of the upper Indus basin, western Himalaya. Our study revealed a negligible control of summer (May-September 2017) precipitation and significant control of summer air temperature (May-September 2017) and winter precipitation over the Chandra River discharge, with 1 °C rise in air temperature leading to 22 ms (15% of mean) increase in the river discharge (R = 0.85; n = 541; p < 0.001). The hydrograph separation of the Chandra River suggests groundwater (38.3 ± 5.6%; 96.8 ms) as a significant source to the river runoff, followed by a direct contribution from glacier melt (30.9 ± 9%; 88.2 ms) and seasonal snowmelt (30.6 ± 5.7%; 84.2 ms), respectively, with negligible contribution from rainfall. Although groundwater is a significant contributor to the river runoff, the infiltration of seasonal snowmelt (54%) and glacier melt (46%) mostly contributed to the groundwater recharge. Present study establishes a linkage between seasonal snowmelt, glacier melt, groundwater, and the river runoff and would be useful to better model and predicts the future changes in the water resources of the upper Indus Basin.
喜马拉雅高海拔地区的冰雪融水是喜马拉雅主要河流的重要水源，特别是在印度河上游流域（UIB），其径流量高达 70%。考虑到印度河流域是一个依赖冰雪融水径流量的最大灌溉系统，研究这些河流的现状和水预算是至关重要的。在这项研究中，我们进行了示踪剂驱动的水文分割，以量化季节性积雪、冰川融水和地下水对源自喜马拉雅西部半干旱地区印度河上游流域的昌德拉河的贡献。我们的研究表明，夏季（2017 年 5 月至 9 月）降水对昌德拉河流量的控制作用可以忽略不计，而夏季气温（2017 年 5 月至 9 月）和冬季降水对昌德拉河流量的控制作用显著，气温升高 1°C 会导致河流流量增加 22 ms（占平均值的 15%）（R=0.85；n=541；p<0.001）。昌德拉河的水文分割表明，地下水（38.3±5.6%；96.8 ms）是河流径流量的重要来源，其次是冰川融水（30.9±9%；88.2 ms）和季节性积雪融水（30.6±5.7%；84.2 ms），而降雨的贡献可以忽略不计。尽管地下水是河流径流量的重要贡献者，但季节性积雪融水（54%）和冰川融水（46%）的渗透主要有助于地下水补给。本研究建立了季节性积雪融水、冰川融水、地下水和河流径流量之间的联系，将有助于更好地模拟和预测印度河上游流域未来水资源的变化。
