Water and sediment yield in the source region of the Yellow River, northeastern Tibetan Plateau: Historical pattern, future evolution, and attribution analysis

Understanding water and sediment yield is essential for effective watershed management, ecological conservation, and socio-economic development, particularly in alpine regions like the Tibetan Plateau (TP), which are highly sensitive to climate change. However, quantifying past and projecting future spatial–temporal changes in water and sediment yield in these areas remains a significant challenge due to the limited availability of long-term observed data. Here, we comprehensively examined the historical patterns, future evolution, and driving factors of water and sediment yield in the source region of the Yellow River (SRYR) on the northeastern TP. The results indicate that from 1990 to 2020, the SRYR exhibited an increasing trend in water yield (10.31 mm per decade) and sediment yield (0.93 t ha⁻¹ per decade), with higher yield observed in the southern part compared to the north. Future projections suggest continued increases in water yield, especially under SSP1-2.6 and SSP2-4.5 scenarios, while sediment yield is expected to decline across all scenarios. The decrease in water and sediment yield is most prominent in the northern and northwestern parts of the basin, while sediment yield increases in the central and western regions. Climatic factors have a stronger influence on the spatial variation of water and sediment yield than underlying surface factors. For water yield, climatic factors explained 39.4–85.3 % of the variability, with precipitation being the most significant factor. For sediment yield, climatic factors explained 22.2–56.3 % of the variation, with dominant factors changing over time—from potential evapotranspiration around 1990, to snow depth around 2000 and 2010, and to temperature around 2020. These findings emphasize the critical role of climate drivers in shaping hydrological and sediment dynamics, offering valuable insights for sustainable management of the TP and Yellow River.