长江镇扬河段世业洲汊道近期河床演变分析

Analysis of Recent Riverbed Evolution in Shiyezhou Branch of Zhenyang Reach of Yangtze River

摘要: 世业洲汊道长期以来处于“左兴右衰”的发展态势，为维护右汊的主汊地位，已进行了一系列的河道和航道整治工程。通过收集大通水文站的水文数据及1959年以来世业洲汊道的分流比、地形等监测数据，将整治工程及特殊水情作为主因分析近期的河床演变。结果表明：世业洲左汊道分流比以1993和2015年为界，分为平台期、上升期和调整期，平台期、调整期引起汊道分流比变化的主因分别是大洪水的冲刷作用、整治工程的实施。其中调整期内世业洲汊道“左兴右衰”的发展态势得到了遏制，调整期内左汊分流比下降了约5%，说明调整期内整治工程实施初期效果明显，汊道分流比尚处于调整期，后期应密切关注分流比变化。本文探讨了世业洲汊道河床演变的影响因素，后期应更注重世业洲左右汊进口段的防护和监测分析，密切关注世业洲左汊潜坝工程上下游区域的冲淤变化。

Abstract: Shiyezhou branch has been in the trend of left branch develops and right branch decays for a long time. In order to maintain the status of the main branch of the right branch, a series of river and channel regulation projects have been carried out. By the hydrological information of Datong hydrological station and the monitoring data of diversion ratio and topography of Shiyezhou branch since 1959, the regulation project and special water regime are taken as the main factors to analyze the recent riverbed evolution. The results show that the diversion ratio of the left branch of Shiyezhou is divided into platform period, rising period and adjustment period by 1993 and 2015. The main reasons for the change of the diversion ratio of the branch during the platform period and the adjustment period are the scouring effect of the flood and the implementation of the regulation project. During the adjustment period, the development trend of Shiyezhou left branch rise and right branch decline has been curbed. During the adjustment period, the diversion ratio of the left branch has decreased by about 5%, indicating that the initial effect of the regulation project during the adjustment period is obvious. The diversion ratio of the branch is still in the adjustment period, and the change of the diversion ratio should be paid close attention to in the later period. The influence factors of riverbed evolution of Shiyezhou branch are discussed. In the later stage, more attention should be paid to the protection and monitoring analysis of the inlet section of the left and right branches of Shiyezhou, and the erosion and deposition changes in the upstream and downstream areas of the left branch submerged dam project of Shiyezhou should be paid attention to as well.