Study on Recent Evolution and Influencing Factors of Sima Bend in the Yangzhong Reach of the Yangtze River

DOI

10.2991/978-94-6463-780-9_9How to use a DOI?

Keywords

River evolution; River simulation; Meander flow; Sima Bend; Yangzhong reach of the Yangtze River

Abstract

Meandering rivers are a common morphological feature in the middle and lower reaches of the Yangtze River. The apex of these bends has historically been a focus area for riverbank protection and channel management due to the impact of lateral flow impingement. With the operation of the Three Gorges Project and upstream cascade reservoirs, the middle and lower reaches of the Yangtze River have experienced long-term and extensive erosion, exacerbating the risk of bank failure in meandering rivers. This study focuses on the Sima Bend in the Yangzhong Reach of the lower Yangtze River, a well-known critical section characterized by severe meandering and intense bank collapse, where the river dynamics are complex, and management is particularly challenging. River evolution analysis indicates that, after the impoundment of the Three Gorges Reservoir, there has been a significant reduction in upstream sediment load, with an average sediment transport of only 129 Mt per year from 2003 to 2022. Significant floods occurred in the lower Yangtze River in 2016, 2017, and 2020, which further intensified the erosion of the Sima Bend. From 2011 to 2021, the general erosion depth reached 10~15 m, which threatened the safety of infrastructure and bank protection works. Numerical and physical model results indicate that during flood conditions, the river’s main flow is significantly skewed towards the bank, with the impingement point located in the area of the left bank. Moreover, there is a pronounced secondary circulation in the vertical direction, which is the hydrodynamic reason for the continuous near-bank erosion in this area. The findings of this study provide technical support for flood control and the safe operation of water-related projects in meandering river sections.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Hualong Luan
AU  - Chengwei Hu
AU  - Yiming Chen
AU  - Chenlong Gao
AU  - Juanjuan Fang
AU  - Tianyin Sun
AU  - Musong Lin
PY  - 2025
DA  - 2025/07/03
TI  - Study on Recent Evolution and Influencing Factors of Sima Bend in the Yangzhong Reach of the Yangtze River
BT  - Proceedings of the 2025 International Conference on Engineering Management and Safety Engineering (EMSE 2025)
PB  - Atlantis Press
SP  - 73
EP  - 86
SN  - 2352-5401
UR  - https://doi.org/10.2991/978-94-6463-780-9_9
DO  - 10.2991/978-94-6463-780-9_9
ID  - Luan2025
ER  -