长江马鞍山河段演变规律与治理思路研究

Research on evolution law of Ma′anshan reach of Yangtze River and regulation

长江马鞍山河段主流摆动频繁,滩槽演变规律复杂,汊道分流比调整幅度较大,局部崩岸频发,影响防洪安全、河势稳定、航道尺度提升以及沿江涉水工程的正常运行,对长江经济带发展和黄金水道建设造成影响,不利于长江大保护工作开展,有必要对该河段演变规律开展进一步研究。基于前人研究成果,采用实测资料归纳总结了该河段河道演变规律,分析了河道整治的重点问题。研究结果表明:马鞍山河段历史上经历了洲滩合并靠岸、汊道减少、河槽束窄、主支汊易位的变化过程;近期,该河段江心洲汊道一直维持左主右支格局,左汊经历了主流过渡段下移、上提、再下移、固化4个阶段;小黄洲汊道受上游江心洲左汊变化影响较大,呈明显的上下游滩槽联动变化态势。针对受水沙条件变化影响,目前该河段存在局部滩槽变动和汊道分流变化、航道难以满足新标准要求等主要问题,提出了稳定河势、改善航道、修复生态等治理思路,可为该河段后续综合治理提供参考依据。

The Ma′anshan Reach of Yangze River mainstream is noted for frequent swing of channel,complicated channel evolution law,large change of diversion ratio,and frequent local bank collapse,affecting flood control safety,river regime stability,channel level improvement and the normal operation of water projects along the river,so it is adverse for the development of the Yangtze River Economic Belt and the golden waterway construction of the Yangtze River.It is necessary to conduct further research on the evolution law of the Ma′anshan Reach of Yangtze River.This paper analyzed the channel evolution law of the Ma′anshan river reach based on the related research results of predecessors and the measured data,and proposed countermeasures for the new problems in the channel regulation.The results showed that the evolution of the Ma′anshan Reach had experienced processes such as the combination of shoal and shore and converging to bank,the shrinkage of branch channel,the narrowing of channel and the exchange of mainstream and tributary channels.Recently,the Jiangxinzhou branch is still maintaining the pattern of“left dominant,right branch”,and the main stream of left branch has gone through four stages of evolving downstream,evolving upstream,further evolving downstream again and maintaining.The branch of Xiaohuangzhou is affected by the change of the left branch of Jiangxinzhou Reach on upstream,showing obvious joint change of beach and trough at upstream and downstream reach.Affected by the change of water and sand conditions,at present,there are some changes in the local tidal flat and the diversion ratio of the branch in Ma′anshan Reach,which is difficult to meet the new standards and requirements of waterway.In view of these problems,the author puts forward some ideas of stabilizing river regime,improving channel and restoring river ecology,which can provide reference for the follow-up comprehensive treatment of the Ma′anshan Reach.