Evolution of the main channel of the Yangtze River

作者：Jinyou Lu, Yonghui Zhu, Zhongwu Jin, Xiaohu Guo, Chao Guo, Peng Chen, Yanjun Wang, Chengwei Hu, Yuan Yuan · 发表于：River · 年份：2023 · DOI：10.1002/rvr2.52 · 被引用次数：15 · 研究领域：Hydrology and Watershed Management Studies、Hydrology and Sediment Transport Processes、Soil erosion and sediment transport

Abstract The construction and operation of the Three Gorges Reservoir and the cascade reservoirs upstream have significantly altered the processes of flow and sediment in the main and tributary channels of the Yangtze River. This has led to substantial adjustments in the riverbed through erosion and deposition, thereby impacting flood protection, water resource utilization, navigation, and the aquatic environment in the Yangtze River basin. In this study, prototype measurements were used to analyze the variations in runoff and sediment load in the main channel of the Yangtze River, as well as the changes and evolution of the riverbed. Mathematical modeling was done to predict the trends in reservoir sedimentation and riverbed adjustments. The results indicate that, apart from the significantly increased runoff and sediment load in the river source region (Zhimenda station) over the past two decades, there is no clear unidirectional trend of increasing or decreasing in the main and tributary annual runoff of the Yangtze River. However, the release of reservoir outflows undergoes significant changes throughout the year due to reservoir regulation. Suspended sediment load in the upper Yangtze River has been decreasing since the 1990s, especially after the operation of the Three Gorges Reservoir and the four cascade reservoirs in the lower reach of the Jinsha River. The factors influencing flow and sediment variations include mainly climate change and human activities such as res...