Studyon Evolution Mechanism And Channel Regulation Of Shiyezhou Braided Channel In The Zhenyang Reach Of The Yangtze River

The zhenyang reach of the Yangtze River is consist of Yizheng waterway,Shiyezhou braidedchannel, Liuwei bend, Hechangzhou braided channel, Dagang waterway from upstream todownstream, is a component of the middle and lower Yangtze River and one of sections that theevolution of river regime is the most complex, renovation is the most difficult to,the cross-straiteconomy is the most developed and the waterborne traffic is the most busy.so the Zhenyangreach has also been identified as a key management section in the main river channel harnessingplanning of the Yangtze River.The situation of shiyezhou braided channel of main channel in the right and branchchanne1in the left was relatively stable in the nineteen eighties.With the reasons of the upperriver regime variation, geological condition, morphological characteristics of channel, the changespeed of left branch to develop and right branch to decline is accelerating in the nearly tenyears.Shiyezhou left branch developing, while the main branch is the right branch begins toshrink, the main hazards of that are firstly effects the flood control safety of peripheral city, at thesecond,right branch blight is bound to impact the usage of "Gold Coast", those established port,power, industrial dock and water intake facilities can not normal use.Thirdly directly influencesthe shipping of the Yangtze River and river regime stability of downstream.Therefore, riverchannel evolution mechanism and evolution law of exploration and research and evolution of thetrend prediction and research on waterway regulation scheme has important theoretical andpractical significance for this section.This paper summarizes the predecessor research results as foundation, based on theprototype observation data,more deeply analyzes cross-sectional form adjustment on the rivercoming water and sediment conditions response. The main research work are as follows:(1) Systematically analyzes riverbed evolution of Shiyezhou braided channel, mainlyincluding the changes of division ratio, thalweg, level, deep slot, reach surface and sectionalcharacteristic value etc.;(2) Explores the main factors of influencing channel evolution of Shiyezhou braidedreach are river regime changes of the upper and lower reaches,riverbed boundary conditions,coming water and sediment conditions and the influence of human activity;(3)Summarizes the main factors of effecting of Shiyezhou braided channel, revealing themain reason of Shiyezhou left branch of development is the convex of sanjiangkou collapse leadto studies node out of control, Shiyezhou branching diversion point fell sharply, changed inflowconditions of the left branch and made a development in left branch and atrophy in the right branch.And according to the above research results,makes channel evolution trend prediction forthe Shiyezhou braided channel;(4)According to the reason of Shiyezhou braided channel evolution and evolution trend,put forward the overall scheme of the regulation, and do movable bed model test for the overallrenovation scheme, the whole scheme of No.3was selected as regulation scheme.