Abstract
The riverine sediment flux (SF) is an essential pathway for nutrients and pollutants delivery and considered as an important indicator of land degradation and environment changes. With growing interest in environmental changes over the Tibetan Plateau (TP), this work investigated the variation of the SF in response to climate change in the headwater of the Yangtze River over the past 30 years. Annual time series of hydro-meteorological variables during 1986–2014 indicate significantly increasing trends of air temperature, precipitation, ground temperature, river discharge, suspended sediment concentration and SF. Stepwise changes were identified with significantly higher values of the above variables in 1998–2014 compared with 1986–1997, which could potentially be attributed to the strong 1997 El Niño event. Double-mass plots indicated that both meltwater and rainfall contributed to the increased river discharge while the increased SF mostly resulted from enhanced erosive power and transport capacities of the increased discharge. However, it was buffered by a decrease in sediment source due to the shift of maximum monthly rainfall from June/July to July/August during which period a denser vegetation cover prevents soil erosion. Partial least squares structural equation modeling analysis confirmed the dominance of warming on the increase of discharge amplified by increased precipitation. It also confirmed that the increased precipitation drives the increase in suspended sediment concentration. Both processes conspire and equally contribute to the stepwise increase of SF. This study provides important insights into the controlling processes for recent SF changes and gives guidance for water and soil conservation on the TP.
| Original language | English |
|---|---|
| Pages (from-to) | 410-418 |
| Number of pages | 9 |
| Journal | Science Bulletin |
| Volume | 65 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 15 Mar 2020 |
Bibliographical note
Funding Information:This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program (2019QZKK0203) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20060202). Fan Zhang designed the research and wrote majority of the paper; Xiaonan Shi, Chen Zeng, Li Wang, Xiong Xiao, Guanxing Wang, Yao Chen, and Hongbo Zhang conducted data analysis and results interpretation; Xixi Lu and Walter Immerzeel gave suggestions on the research design and improvement; all authors contributed to the writing with Fan Zhang as the lead author.
Funding Information:
This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program ( 2019QZKK0203 ) and the Strategic Priority Research Program of the Chinese Academy of Sciences ( XDA20060202 ). Fan Zhang is a professor at Institute of Tibetan Plateau Research, Chinese Academy of Sciences. She received her B.S. and M.S. degrees from Tsinghua University in 1998 and 2000, respectively, and Ph.D. degree from University of Central Florida in 2005. Her research focuses on watershed hydrology, soil erosion and sediment transport, and reactive transport modeling. Xiaonan Shi is an associate professor at Institute of Tibetan Plateau Research, Chinese Academy of Sciences. She received her B.S. and M.S. degrees from Xi’an University of Technology in 2003 and 2006, respectively, and Ph.D. degree from China Agricultural University in 2010. Her main research interests focus on the fields of watershed hydrology and mass transport in water (including sediment, solution, and stable isotope).
Publisher Copyright:
© 2019 Science China Press
Funding
This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program (2019QZKK0203) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20060202). Fan Zhang designed the research and wrote majority of the paper; Xiaonan Shi, Chen Zeng, Li Wang, Xiong Xiao, Guanxing Wang, Yao Chen, and Hongbo Zhang conducted data analysis and results interpretation; Xixi Lu and Walter Immerzeel gave suggestions on the research design and improvement; all authors contributed to the writing with Fan Zhang as the lead author. This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program ( 2019QZKK0203 ) and the Strategic Priority Research Program of the Chinese Academy of Sciences ( XDA20060202 ). Fan Zhang is a professor at Institute of Tibetan Plateau Research, Chinese Academy of Sciences. She received her B.S. and M.S. degrees from Tsinghua University in 1998 and 2000, respectively, and Ph.D. degree from University of Central Florida in 2005. Her research focuses on watershed hydrology, soil erosion and sediment transport, and reactive transport modeling. Xiaonan Shi is an associate professor at Institute of Tibetan Plateau Research, Chinese Academy of Sciences. She received her B.S. and M.S. degrees from Xi’an University of Technology in 2003 and 2006, respectively, and Ph.D. degree from China Agricultural University in 2010. Her main research interests focus on the fields of watershed hydrology and mass transport in water (including sediment, solution, and stable isotope).
Keywords
- Alpine catchment
- Changing trend
- Climate change
- Sediment flux
