Managing the Nile under climate change: A systematic review of hydrological shifts and adaptive strategies for transboundary water security

Study Region: The Nile River Basin (NRB), spanning 11 countries in East Africa and supporting over 300 million people. Study Focus: This study synthesizes three decades of research using an AI-enhanced PRISMA review to assess impacts of climate change, land-use change, and infrastructure on water availability and risks across the basin. New Hydrological Insights for the Region: The review reveals pronounced spatial heterogeneity in hydrological responses. In the Blue Nile, discharge trends are mixed and often statistically insignificant, with recent changes increasingly linked to land-use dynamics rather than climate alone. In the White Nile, hydrology shows multi-decadal variability rather than consistent long-term trends. A major regime shift in 1961, associated with a positive Indian Ocean Dipole (IOD), raised Lake Victoria by about 2 m and increased baseline outflows. Flows declined through the 1990s, dropped sharply in the early 2000s due to dam operations, and reached record highs in 2020 following IOD-driven extreme rainfall. Attribution studies indicate climate change has likely contributed to increased White Nile flows in recent decades, although uncertainties remain regarding the roles of climate, land use, and human interventions. Future rainfall and river flow projections show wide divergence, ranging from − 10 % to + 25 % for rainfall and − 20 % to + 40 % for discharge by late century, highlighting uncertainty in future water availability and increasing pressure on transboundary water management.