Regime shift in morphology of the Yangtze Estuary under changing environment and it's management
He Qing
Zhun Chunyan
Guo Leicheng
Hou Lijun
Peng Zhong
Zhang Weiguo
Abstract：The Yangtze Estuary is a large,multi-channel deltaic system controlled by both river runoff and tidal forces.It serves as a ritical area for national strategies such as the Yangtze River Economic Belt and the integrated development of the Yangtze delta.To gain a deeper understanding of the morphological evolution and to support sustainable development of the Yangtze delta,comprehensive analysis of the changing conditions,morphological evolution,challenges and management measures are conducted.The research shows that under the condition of global climate change,the Yangtze Estuary is facing multiple changes such as 75%～90%reduction in river sediment transport,continuous rise of sea level,and increase in the number of human water-related projects,and the transformation of the Yangtze Estuary depositional geomorphic system has begun to appear.It's found that the channels are deepened and narrowed,the shorelines stabilized,the mouth zone is shifting from sedimentation to erosion,and the delta front is experiencing accelerated erosion.The water area has cumulatively decreased by approximately 1500 km² over the past 70 years(1950-2020).The trend of artificial channelization could lead to reduced deposition in the estuary,exacerbating erosion and flood hazards in a sediment-deficient environment.The entire estuary exhibits four-stage of evolution,namely developing trend characterized by natural siltation—stability with adjustment—accretion to erosion transition—erosion and shrinkage.The present Yangtze Estuary is transitioning from a natural,slow depositional system to one characterized by erosion and human-driven adaptive adjustments.Future estuarine management and protection efforts should enhance the understanding of natural-social coupling mechanisms across river-estuary-coast systems.This includes development of real-time field monitoring,medium and long term geomorphic numerical simulations,and digital twin technologies.Balancing ecological protection,resiliece recovery,and safety maintenance is crucial to enhancing the estuarine system's capacity to withstand floods,erosion,and other hazards.
Keywords：Yangtze Estuarytidesedimentmorphologyregime shifthuman activitiessustainable development
Publication Date：2024-08-27
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 12-19 )