Advancing isotope-based understanding of water resources in glacierized catchments to adapt to a changing climate

The livelihoods of millions of people worldwide depend on meltwater from glacierized catchments, which are critical resources for drinking water, agriculture, and power production. However, climate warming profoundly affects the water storage and transfer functions of these catchments, posing significant challenges to water resource management in mountain regions. In alignment with the United Nations’ designation of 2025 as the International Year of Glacier Protection and the pursuit of Sustainable Development Goal 6 (Clean Water and Sanitation), there is an urgent need to understand and address these changes and develop adaptive strategies.The relative contributions of glacier melt, snow melt, precipitation, groundwater, and other sources to streamflow remain poorly understood in many glacierized regions. This knowledge gap complicates efforts to predict and manage water resources amid expected climatic changes. Isotope-based methodologies provide a powerful tool to quantify these contributions, offering valuable insights into the current and future status of water resources in glacierized catchments.As part of the coordinated research project initiative titled “Understanding Hydrological Processes in Glacierized Catchments under Changing Climate using Isotope-Based Methodologies (F33031)” by the International Atomic Energy Agency (IAEA), a key objective is to develop a comprehensive database of isotopic signatures for the various endmembers contributing to streamflow. These endmembers, which vary depending on the specific catchment, include for example glacier melt, snowmelt, precipitation, groundwater and outflow from rock-glaciers and ice-cored moraines.This research aims to establish a global reference framework to support the development and application of isotope-based methodologies, enabling a standardized approach to understanding flow paths and their contributions to streamflow. By elucidating these dynamics, the framework will help assess how contributions evolve with seasonal and inter-annual climatic variations. These insights are essential for accurately evaluating changes in total discharge volumes and implementing sustainable water management strategies to address the impact of climate change on mountain hydrology.