Author(s): Chao Guo; Dongfang Liang; Yuan Yuan; Lingyun Li; Xiaohu Guo; Jinyou Lu
Linked Author(s): Jinyou Lu, Dongfang Liang, Lingyun Li
Keywords: Large reservoirs; Hydro-sediment regime; River channel evolution; Multifaceted influences; Middle-lower Yangtze River
Abstract: Under the influence of human activities, particularly the construction of large reservoirs, the comprehensive impact on rivers has become a globally focal point of research. It holds crucial implications for reservoir planning, river conservation, and management. The construction and operation of the Three Gorges Reservoir (TGR), along with other mega dams constructed upstream, have resulted in significant alterations to the hydro-sediment regime, exerting multifaceted influences on river. This study focuses on the channel evolution and impacts in the middle-lower reaches of the Yangtze River over the past two decades, based on the analysis of measured data since the operation of TGR in 2003. This study elucidated the spatiotemporal variation in runoff and sediment flux. In the past 20 years, the overall runoff has remained stable, while the distribution has been flattened. Sediment flux has significantly decreased and the distribution within the year has become more concentrated. From 2003 to 2020, the reach from Yichang to Datong experienced a scouring of 3108.87 Mm3, with an average scouring depth of about 1.8 m. Subsequently, an assessment of the comprehensive impacts of hydro-sediment regime changes and river channel evolution on flood control, navigation, and river infrastructure is conducted. The research findings contribute to supporting the conservation and management of the Yangtze River, and provide valuable insights for the management of similar river basins worldwide.
Year: 2024