Water Quality and Sediment Behaviour of the Future: Predictions for the 21st Century (Proceedings of Symposium HS2005 at IUGG2007, Perugia, July 2007).  IAHS Publ. 314, 2007, 11-19

 

Impacts of human activities on the sediment regime of the Yangtze River

 

QIONGFANG LI, ZHENHUA ZOU, ZIQIANG XIA, Wei zhang & huiqing wang

State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China

qfli@hhu.edu.cn

 

Abstract The Yangtze River (Changjiang) is one of the most important rivers in the world, and the alterations in its hydrological regime have global-scale impacts. However, with population increase and economic growth, the sediment regime of the Yangtze River has been altered to some extent by human activities, including dam construction, deforestation, soil and water conservation, etc. The alteration in the sediment regime of the Yangtze River will unavoidably influence its morphology and geomorphology, the delta evolution and the ecosystem health and stability. To assess dam-induced alterations in the sediment regime of the Yangtze River quantitatively, the Danjiangkou Reservoir, the Gezhouba Reservoir and the Three Gorges Reservoir have been selected as case study sites, and the whole study period was divided into four sub-periods according to the years when these three reservoirs started to store water. On the basis of the time series of daily sediment discharge from six key hydrological stations (Wanxian, Yichang, Hankou, Datong, Baihe and Xiantao), the changes in annual, seasonal and monthly sediment load in different sub-periods, and the driving forces, were explored. The results in this paper could provide a reference for the assess­ment of impacts of human activities on the health and stability of the Yangtze River ecosystem.

 

Key words Yangtze River; Danjiangkou Reservoir; Gezhouba Reservoir; Three Gorges Reservoir; sediment regime; hydrological changes