Source: AGU Advances
Himalayan river flow is an essential source of water for downstream communities. Understanding the future of this resource requires investigating where the precipitation moisture comes from and gets transferred to the river flow. After precipitation, the intermediate water storage in groundwater, snow, and ice plays an important role that needs to be understood. To determine the characteristic signature of different moisture sources partitioning into storage, samples collected from water sources in Central Himalayas in Nepal were analyzed for isotope composition. Combining these with satellite observations and models, Hassenruck-Gudipati et al.  showed that the rainfall before the Indian Summer Monsoon is derived from the Gangetic foreland, while monsoon precipitation is from the Indian Ocean and Arabian Sea. During the dry season, groundwater was the principal source of river flow. This works highlights how water sources feeding the rivers change throughout the year and how isotope analysis can be used as an effective tool in similar future studies.
Citation: Hassenruck-Gudipati, H. J., Andermann, C., Dee, S., Brunello, C. F., Baidya, K. P., Sachse, D., et al. . Moisture sources and pathways determine stable isotope signature of Himalayan waters in Nepal. AGU Advances, 4, e2022AV000735. https://doi.org/10.1029/2022AV000735
—Tissa Illangasekare, Editor, AGU Advances