Linkage between riverbed scouring or deposition and the evolution of central bars: Case study in the Yangzhong reach of the Yangtze River

Understanding the relationship between unbalanced riverbed scouring or deposition and the evolution of central bars in natural conditions and human activity is useful for river regime control and waterway improvement projects. Toward this end, we utilized the Yangzhong reach in the lower reaches of the Yangtze River as a case study and evaluated runoff, sediment content, and topographical data measured over the past 70 years (1951–2021). With the decrease in the amount of incoming sediment in the river basin, the Yangzhong reach exhibited a continuous state of scouring. The cumulative riverbed scouring volumes of the low-water and flood channels from 1981 to 2021 were 3.97×108 and 4.14×108 m3, respectively, with the riverbed scouring volume of the low-water channel accounting for 95.9