The distal reach of the Lower Jingjiang River (LJR) in the middle of the Yangtze River consists of five adjacent bends, among which the Qigongling Bend is a Ω-shaped meander with a mean sinuosity of 2.2 and the narrowest neck 525 m in width. This bend is slowly approaching neck cutoff owing to progressive bank erosion. An abnormal phenomenon has occurred in this bend since the Three Gorges Reservoir (TGR) began to operate in 2003 which is erosion in the inner bank zone and deposition in the outer bank zone. This problem has not been fully understood because of the interplay of changes in water-sediment, bank erosion, and artificial bank revetment. In this study, aerial and remote sensing images, hydrological data, channel topography, and an existing bank erosion model are used to reveal channel morphodynamics of this bend and the trend of the potential neck cutoff induced by bank erosion. The study results show that the clear water released from the TGR has provided by forcefully eroded the point bar of inner bank but failed to scour the outer bank due to the protection of bank revetment since the 1990s. Thus far, the outer bank zone near the bend apex has increasingly widened in conjunction with the formation of 2 emerging sand bars. Consequently, the thalweg of the main channel has laterally shifted toward the inner bank by roughly 800 m. More severely, the rate of bank retreat on the upstream side of the bend neck was about 4.5 m/yr in 2010–2019, but the downstream side of this neck was experienced slight deposition. Bank erosion could be accelerated by progressively increasing erosion and eventually trigger the occurrence of neck cutoff in the next few decades, thereby significantly altering the quasi-equilibrium regime of channel morphodynamics in the LJR.

长江中下游的靖江下游（LJR）的远端由五个相邻的弯道组成，其中，气功岭弯道呈Ω形，平均弯曲度为2.2，最窄的颈部为525 m。由于逐渐的堤岸侵蚀，该弯曲逐渐接近颈部切除。自三峡水库（TGR）于2003年开始运行以来，此弯道发生了异常现象，这是内河岸区的侵蚀和外河岸区的沉积。由于水沉积物变化，河岸侵蚀和人为河岸护岸的变化相互影响，因此尚未完全理解此问题。在这项研究中，航空和遥感影像，水文数据，河道地形，并利用现有的堤岸侵蚀模型揭示了该弯道的河道形态动力学以及堤岸侵蚀引起的潜在颈部割断的趋势。研究结果表明，自1990年代以来，TGR释放出的清水是通过强力侵蚀内河岸的堤坝而提供的，但由于对河岸护岸的保护，未能冲刷外河岸。到目前为止，随着形成两个新出现的沙洲，弯曲顶点附近的外岸区域越来越宽。因此，主河道的海藻已向内堤横向偏移了约800 m。更严重的是，2010-2019年，弯颈上游侧的岸岸退缩速度约为4.5 m / yr，但该颈流的下游侧出现了轻微的沉积。