Quantitative relationship between channels and bars in a tidal reach of the lower Yangtze River: Implications for river management

Deep-water navigation channels in the tidal reaches of lower Yangtze River are affected by water and sediment fluxes that produce complex shoals unstable channel conditions. The Fujiangsha reach is particularly difficult to manage, as it has many braided within fluctuation zone. In this study, hydrologic topographic data from 2012 2017 were used examine variations deposition erosion, flow diversion, shoals, Since Three Gorges Dam became operational storage was initiated, shown an overall tendency toward erosion. Channels deeper than 10 m accounted for 83.7% total erosion during 2012–2017. Moreover, dominant channel-forming sediments have gradually changed suspended a mixed load bed-load sediments. Deposition volumes these varied significantly among different channels, but mainly occurred Fubei channel. Furthermore, periodic Jingjiang point bar followed deposition-erosion-deposition pattern, downstream Shuangjian shoal mid-channel been scoured shortened. Approximately 44.0% bed upstream deposited 12.5-m deep increased river flood season constituted 59.3% 40.7%, respectively, amount siltation