From Water Sharing to Water Scarcity: Managing Depleted Aquifers, Dried Lakes, and Shrinking Glaciers in Transboundary Water Systems

Convener: Ali Torabi Haghighi | Co-conveners: Aziza BaubekovaECSECS, Abror Gafurov, Agnes Tahy, Juraj Parajka, Carla CataniaECSECS

Water scarcity is an escalating challenge in transboundary river basins and shared aquifers under climate change and broader global transformations. Declining precipitation, increasing drought frequency and severity, glacier retreat, groundwater depletion, and growing sectoral water demands are intensifying pressure on shared water resources. At the same time, data gaps and uncertainties in climate projections continue to hinder effective, cooperative transboundary water governance. Arid and semi-arid regions with long-standing exposure to water scarcity, such as the Middle East, Central Asia, and Southern Africa, offer valuable insights into hydrological processes under persistent stress, data-limited environments, modeling strategies, and adaptive management responses. Meanwhile, river basins traditionally considered water-abundant, including the Danube River Basin, are increasingly experiencing droughts, prolonged low-flow conditions, and rising abstractions. These emerging dynamics underscore the need for improved understanding of evolving scarcity patterns and for proactive adaptation strategies. Addressing these complex challenges requires a holistic and integrative approach that explicitly incorporates the Water–Energy–Food-Ecosystem (WEFE) Nexus to support benefit-sharing and cooperation among riparian states. Recent advances in data-driven decision-making, particularly through remote sensing, hydrological and hydro-climatic modeling, and uncertainty assessment, offer significant opportunities to reduce data gaps and strengthen transboundary water management. Equally important is human and institutional capacity building, which remains central to translating scientific knowledge into effective policy and practice. This session aims to foster cross-sectoral and transboundary collaboration, enhance data accessibility, and promote science-based strategies for securing water resources in shared basins under climate change. Contributions are invited that address spatial and temporal patterns and changes in components of the water cycle, and that present innovative approaches and methods for strengthening transboundary cooperation in applied hydrology. Particular emphasis is placed on observations, remote sensing, modeling, uncertainty analysis, and integrated water resources management.