Analysis of Shoal-Channel Evolution and Navigation Conditions in Zhou-Tian Reach of the Middle Yangtze River

Taking the Zhou-Tian reach in the middle Yangtze River as the study object, this research analyzes the evolution characteristics of shoals and channels along with navigation conditions changes after the first-phase Jingjiang regulation project, based on measured hydrological and topographic data. Key findings from March 2022 to May 2024 include: The Jiuhuasi fluvial bar showed slight upstream advancement at its head and variations at its tail, while the Qijiatai bar on the opposite bank remained stable.The Zhougongdi central bar and Jiaoziyuan bar exhibited alternating erosion-deposition patterns along their right margins, with minor retreat observed at the tail of Jiaoziyuan bar.The Xinchang bar maintained morphological stability, while the left margin of Tianxingzhou head experienced erosion.Navigation channel observations revealed: A continuous 4.5-meter-deep channel formed at the entrance (Jiuhuasi area) with stable morphology.The Yanjiatai area showed planar morphological variations in its 4.5m channel.Sand tongues (<4.5m depth) intruded into main channels near Tanjiazhou-Caofangguan (left bank) and Jiaoziyuan bar tail, creating interlaced 4.5m channels.While Tianxingzhou waterway maintained continuous 4.5m channels, small sand tongues near Hufengou and boundary fluctuations at Tuoyangshu bar adversely affected navigation stability.