Abstract:Under the combined impacts of climate change and human activities, the ecological barrier regions of western China exhibit significant reductions in solid water storage, increases in liquid water, declining water resource stability and non-steady-state characteristics in hydrological systems. Water allocation risks have increased, making it exponentially more difficult to ensure water security. Transboundary water resource development can lead to spillover risks, requiring urgent research on sustainable water resource use and adaptation strategies. The water cycle in western China is driven by both natural and anthropogenic factors, yet fundamental research on water cycle dynamics and resource management under changing environments remains weak. There is a lack of systematic solutions for theoretical breakthroughs and core technologies aligned with new water governance paradigm. Based on the analysis of water resource changes and existing challenges in the ecological barrier regions, this study proposes to focus on key scientific and technological issues: water cycle dynamics and water resources implications in the Qinghai-Xizang Plateau, efficient water utilization and conservation technologies, water-energy-food-ecology nexus and regional sustainable development under changing environments, transboundary water resources management for international rivers, surface water-groundwater-ecosystem interactions and safetyensuring technologies, “space-air-ground” integrated digital twin basin technologies, and flood/drought disaster early warning systems. Policy recommendations are provided to strengthen scientific and technological support for sustainable water resource management in the western ecological barrier regions.