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Recent climate change has caused an increase in warming-driven erosion and sediment transport processes on the Tibetan Plateau (TP). Yet a lack of measurements hinders our understanding of basin-scale sediment dynamics and associated spatiotemporal changes. Here, using satellite-based estimates of suspended sediment, we reconstruct the quantitative history and patterns of erosion and sediment transport in major headwater basins from 1986 to 2021. Out of 13 warming-affected headwater regions, 63% of the rivers have experienced significant increases in sediment flux. Despite such intensified erosion, we find that 30% of the total suspended sediment flux has been temporarily deposited within rivers. Our findings reveal a pronounced spatiotemporal heterogeneity within and across basins. The recurrent fluctuations in erosion-deposition patterns within river channels not only result in the underestimation of erosion magnitude but also drive continuous transformations in valley morphology, thereby endangering local ecosystems, landscape stability, and infrastructure project safety. Climate change intensifies erosion and sediment transport in rivers of the Tibetan Plateau. Satellite data unveil unprecedented patterns of sediment deposition in rivers. Pronounced spatiotemporal heterogeneities within and across basins are found. [ABSTRACT FROM AUTHOR]

Alpine grasslands are the dominant vegetation of the Tibetan Plateau (TP) and are essential to understanding the mechanism of change in water use efficiency (WUE) in high-cold ecosystems in a changing environment. However, it is still unclear how the WUE of different alpine grasslands respond to changes in precipitation. Therefore, we investigated the variations in growing season WUE and its drivers among different grassland types, including alpine meadow of permafrost (PAM), alpine meadow of seasonal frost (SAM), alpine steppe of permafrost (PAS), and alpine steppe of seasonal frost (SAS), in different precipitation years. The mean growing season WUE was significantly higher for alpine meadow and seasonal frost regions and lower for alpine steppe and permafrost regions. WUE increased significantly in the alpine meadow (PAM and SAM) but decreased (PAS) or varied little (SAS) in the alpine steppe during the period of 1982–2014. Compared to normal years, WUE in the PAS region increased by 22% and 10% in severe and mild dry years, respectively, and decreased by approximately 10% in wet years. For the alpine meadow, WUE decreased more in severe dry years than in mild dry years and increased slightly in wet years. In different precipitation years, WUE for all grassland types was mainly controlled by the vegetation factor. Results suggest that the WUE in alpine grasslands, especially in the PAS region, may decline if the "dry gets wet, wet gets dry" happen over the TP in the future. • Increasing soil moisture dominated the increasing water use efficiency (WUE) in the alpine meadow ecosystems. • Decreasing WUE in the alpine steppe of permafrost was due to the negative effect of precipitation and soil moisture on WUE. • Contrasting responses of WUE to precipitation changes were observed in the alpine steppe and alpine meadow ecosystems. [ABSTRACT FROM AUTHOR]