Abstract:The Tibetan Plateau is the source zone of major rivers, which provide water resources for more than 2 billion people downstream. Compared with runoff, riverine sediment load is considered as a more sensitive variable in response to climate and land surface process changes, and also as an important index to quantify regional land degradation and soil resource changes. In this study, 8 major rivers originated in the Tibetan Plateau, including Yerqiang River, Shule River, Heihe River, Yarlung Tsangpo River, Nujiang River, Yellow River, Yangtze River, and Lancang River, were selected to study the variation of sediment load in the source zone or upper reaches. Firstly, the general amount and spatial variation of runoff and sediment load of these rivers were explored. Secondly, the changes of riverine sediment load in recent decades (1960-2017) were analyzed, with the spatial and temporal variations of sediment load compared to climate (temperature, precipitation) and land surface process (glacier, frozen soil, vegetation cover) factors. Thirdly, the uncertainty of sediment load variation associated with interaction of multi-factors was discussed. Finally, the significant impacts of sediment load variation on the ecological environment and the safety of hydropower projects was pointed out with typical cases. Nowadays, the scarcity of hydrometeorological data is a major challenge to understand the variation of riverine sediment load from the Tibetan Plateau and assess the impacts. It is urgent to strengthen observation and modeling studies to reveal the complex mechanism of sediment transport changes, so as to provide scientific basis for the sustainable utilization of water and soil resources on the Tibetan Plateau and the downstream water resources management, so as to serve the national ecological security.