Trends in suspended sediment grain size in the upper Yangtze River and its tributaries, as influenced by human activities

The non-uniform sediment input has played a significant role in the bed evolution in the middle and lower Yangtze River, which indirectly influences the amount of the sediment transported into the East China Sea every year. However, it has been dramatically changed by the climate change, especially the human activities in the upper Yangtze River, not only the amount, but also the grading. The average annual sediment load has reached to 402.6 million tons since 1960s, while showing a decreasing and refining trend mostly influenced by the human activities, such as soil and water conservation, and large hydropower projects. The most direct consequence of these changes was to cause severe erosion in the middle and lower Yangtze River, further to bring about fluvial regime adjustment. In this article, a series of daily and annual averaged sediment transport data since 1960’ were collected and analyzed to find the impacts of the significant human activities on the non-sediment input of the middle Yangtze River, and then its variation tendency was predicted, affected by the existed large hydropower projects and to be build ones in the upper Yangtze river. The result shows that the non-uniform sediment input of the middle Yangtze River was slightly reduced by the operation of Gezhouba Project and the up and middle Yangtze River water and soil conservation prevention and control projects, and further less after the impoundment of Three Gorges Reservoir, meanwhile its grading has been getting finer and finer. In future, along with the normal operation of the Three Gorges Reservoir and the built of the cascade reservoirs in the upper main stream and tributaries of the Yangtze River, it will be continuously reduced and refined.

Download Full-text

Anthropogenic impacts on suspended sediment load in the Upper Yangtze river

Regional Environmental Change ◽

10.1007/s10113-011-0222-0 ◽

2011 ◽

Vol 11 (4) ◽

pp. 857-868 ◽

Cited By ~ 21

Author(s):

Jie Wei ◽

Xiubin He ◽

Yuhai Bao

Keyword(s):

Suspended Sediment ◽

Yangtze River ◽

Sediment Load ◽

Anthropogenic Impacts ◽

Suspended Sediment Load ◽

Upper Yangtze River ◽

The Upper Yangtze River

Download Full-text

Recent changes of suspended sediment yields in the Upper Yangtze River and its headwater tributaries

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-367-297-2015 ◽

2015 ◽

Vol 367 ◽

pp. 297-303 ◽

Cited By ~ 2

Author(s):

X. Zhang ◽

Q. Tang ◽

Y. Long ◽

X. He ◽

A. Wen

Keyword(s):

Suspended Sediment ◽

Water Conservation ◽

Yangtze River ◽

Principal Role ◽

Sediment Yields ◽

Upper Yangtze River ◽

Jialing River ◽

Environmental Rehabilitation ◽

Runoff Discharge ◽

The Upper Yangtze River

Abstract. 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.

Download Full-text