长江太仓—南通河段河道演变特性与航道治理思路分析

长江太仓—南通段深水航道治理是江苏省境内12.5 m深水航道建设的首期工程。该河段地处长江潮汐河口的过渡段,径流与潮流强弱交替变化频繁,水沙运动复杂多变,洲滩冲淤演变剧烈,航道条件极不稳定,治理难度大。通过长期观测分析,辨析河床演变规律,揭示碍航浅区成因,从疏浚、全面控制洲滩形态、控制洲滩关键边界等不同治理对策进行深入研究,形成"稳定航道主边界、增强浅区落潮动力"的治理认识。目前,控制洲滩关键边界、利用河流动力延伸工程效力的治理方案已通过审批,即将开工实施。

Regulation scheme of Taicang-Nantong deep-water fairway in Yangtze River

The regulation of Taicang-Nantong deep-water fairway in Yangtze River is the first project of a 12.5 m deep-water fairway built in Jiangsu province.Since the river reach is located in a crossing of tidal estuary of the Yangtze River,it is characterized by a frequent alternative change in runoff and tidal flow,an intricate and changeable water and sediment movement and an acute erosion and deposition of islands and bars,so its fairway condition is highly unstable and it is difficult to be regulated.Through a long-term measurement and analysis,the regularities of riverbed evolution is discriminated and contributing factors to cause navigation-obstructing shoal zones are revealed,and an in-depth study are carried out from different regulation countermeasures such as dredging,the overall control of shapes of islands and bars and the control of key boundaries of islands and bars,thereby forming a regulation concept of"stabilizing main boundary of fairway and enhancing the ebb-tide dynamics of shoal zones".At present,a regulation scheme of controlling the key boundary of islands and bars,and utilizing the function of a river dynamic extension project has been examined and approved,and will be implemented.