PIAHS Proceedings of the International Association of Hydrological Sciences PIAHS Proc. IAHS 2199-899X Copernicus Publications Göttingen, Germany 10.5194/piahs-367-297-2015 Recent changes of suspended sediment yields in the Upper Yangtze River and its headwater tributaries Zhang X. 1 Tang Q. 1 2 Long Y. 1 He X. 1 Wen A. 1 Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institution of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China University of Chinese Academy of Sciences, Beijing 100049, China 03 03 2015 367 297 303 Copyright: © 2015 X. Zhang et al. 2015 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://piahs.copernicus.org/articles/367/297/2015/piahs-367-297-2015.html The full text article is available as a PDF file from https://piahs.copernicus.org/articles/367/297/2015/piahs-367-297-2015.pdf

Suspended sediment yields in the Upper Yangtze River and its four headwater tributaries (i.e. Jinsha, Min, Jialing and Wu) have declined significantly during recent decades. Compared with 1956–1970, mean annual suspended sediment yield during 2001–2011 was reduced by 84% in the Upper Yangtze River at Yichang, by 34% in the Jinsha at Pingshan, by 84% in the Jialing at Beibei, by 75% in the Wu at Wulong, and by 48% in the Min at Gaochang. Linking these observed decadal changes of runoff discharge and suspended sediment load to dam construction and multiple environmental rehabilitation projects (e.g. soil-water conservation, reforestation) during the past decades, it can be concluded that the construction of large dams on the main stem and major tributaries of the Upper Yangtze River has played a principal role in the reduction of fluvial suspended sediment yields, while the environment rehabilitation projects may make limited contributions to the changes in suspended sediment yields, except for the Jialing River.