How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam?

How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam?

Guo, Leicheng (Shanghai Estuarine and Coastal Science Research Center)
Su, Ni (Tongji University)
Zhu, C. (TU Delft Coastal Engineering; Shanghai Estuarine and Coastal Science Research Center)
He, Qing (Shanghai Estuarine and Coastal Science Research Center)

2018

Streamflow and sediment loads undergo remarkable changes in worldwide rivers in response to climatic changes and human interferences. Understanding their variability and the causes is of vital importance regarding river management. With respect to the Changjiang River (CJR), one of the largest river systems on earth, we provide a comprehensive overview of its hydrological regime changes by analyzing long time series of river discharges and sediment loads data at multiple gauge stations in the basin downstream of Three Gorges Dam (TGD). We find profound river discharge reduction during flood peaks and in the wet-to-dry transition period, and slightly increased discharges in the dry season. Sediment loads have reduced progressively since 1980s owing to sediment yield reduction and dams in the upper basin, with notably accelerated reduction since the start of TGD operation in 2003. Channel degradation occurs in downstream river, leading to considerable river stage drop. Lowered river stages have caused a ‘draining effect’ on lakes by fostering lake outflows following TGD impoundments. The altered river–lake interplay hastens low water occurrence inside the lakes which can worsen the drought given shrinking lake sizes in long-term. Moreover, lake sedimentation has decreased since 2002 with less sediment trapped in and more sediment flushed out of the lakes. These hydrological changes have broad impacts on river flood and drought occurrences, water security, fluvial ecosystem, and delta safety.

Changjiang
River discharge
Sediment loads
Streamflow
Three Gorges Dam

http://resolver.tudelft.nl/uuid:c8e4a304-4273-4c58-aecf-4db446e6f353

https://doi.org/10.1016/j.jhydrol.2018.03.035

2018-09-15

0022-1694

Journal of Hydrology, 560, 259-274

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2018 Leicheng Guo, Ni Su, C. Zhu, Qing He