Impact of climate change and vegetation greening on sediment transport in the Yarlung Tsangpo River

The Yarlung Tsangpo River (YTR), an essential headwater of the Tibetan Plateau, has experienced rapid warming and significant changes in sediment load over recent decades, threatening aquatic ecosystems, infrastructure integrity, and downstream water security. However, the relative and combined impacts of climate change, cryosphere degradation, and vegetation greening on sediment load remain insufficiently quantified, particularly across spatially heterogeneous cryosphere-fed river basins. Here, we integrate long-term (1981–2008/2009) in-situ hydrological observations with high-resolution meteorological and vegetation datasets to examine the sediment dynamics of the YTR in response to changing climate, cryospheric processes, and vegetation conditions. Our results reveal that sediment load has increased by 50–88 %, outpacing the 20–27 % rise in runoff during the study period. In the relatively cold and arid upstream region, sediment load is sensitive to both temperature (35 ± 2 %) and precipitation (45 ± 5 %), with warming-induced glacier retreat and permafrost thaw further amplifying sediment supply. In contrast, the relatively warm and humid downstream region is dominated by pluvial erosion associated with intensified rainfall (53 ± 3 %). These findings highlight pronounced spatial variations in sediment-climate-connectivity interactions and underscore their growing impacts on water quality, reservoir sedimentation, and hydropower efficiency. The pre-dam observational data presented here serve as a valuable baseline for future assessments of infrastructure impacts, offering critical support for hydropower planning, ecosystem protection, and adaptive sediment management under changing environmental conditions.