Department of Earth Sciences, University of Kashmir, Srinagar, India.
Geosciences Division, Physical Research Laboratory (PRL), Ahmadabad, India.
Isotopes Environ Health Stud. 2022 Mar;58(1):18-43. doi: 10.1080/10256016.2021.2011725. Epub 2021 Dec 10.
We used stable water isotopes of oxygen and hydrogen to identify and estimate the seasonal contribution of precipitation to the regional hydrology of Sindh and Rambiara catchments of western Himalayas. The different source waters exhibit significant spatio-temporal variations that correspond to the change in seasonal meteorology, precipitation form and moisture sources. The two-component hydrograph separation based on -excess suggests that the western disturbances (WD) contribute dominantly (76 ± 4 %) to the regional hydrology, compared to Indian summer monsoon (ISM) rainfall (24 ± 4 %). A comparison of -excess values of WD and ISM indicates the groundwater consists of 90 ± 3 % WD sources and 10 ± 2 % ISM sources, signifying distinct seasonal variations in groundwater recharge sources. The sine wave model results showed that the annual mean residence time (MRT) of groundwater for the Sindh catchment (5.8 ± 0.6 months) is greater than the Rambiara groundwater (3.6 ± 0.5 months). The lower isotope values observed in the river water than in the precipitation suggest its origin from the snowmelt. This study provides valuable insights into the hydrological processes operating in the high altitude Himalayan catchments to facilitate the improved understanding of runoff generation mechanisms and water resource management in future climate change scenarios.
我们使用稳定的氧和氢同位素来识别和估计西喜马拉雅山信德和兰比拉亚流域的降水对区域水文学的季节性贡献。不同的水源表现出显著的时空变化，与季节性气象变化、降水形式和水汽源的变化相对应。基于 -excess 的双组分水文分离表明，与印度夏季季风（ISM）降雨（24 ± 4%）相比，西风扰动（WD）对区域水文学的贡献更大（76 ± 4%）。WD 和 ISM 的 -excess 值的比较表明，地下水由 90 ± 3%的 WD 来源和 10 ± 2%的 ISM 来源组成，这表明地下水补给来源具有明显的季节性变化。正弦波模型结果表明，信德流域地下水的年平均停留时间（MRT）（5.8 ± 0.6 个月）大于兰比拉亚地下水（3.6 ± 0.5 个月）。河水的同位素值低于降水，表明其来源于融雪。本研究深入了解了高海拔喜马拉雅流域的水文过程，有助于在未来气候变化情景下更好地理解径流生成机制和水资源管理。
