Study On The Applicability Of Taipingkou Channel Waterway Regulation In The Middle Reaches Of Yangtze River

After the Three Gorges Project impounds successfully,most upstream flow and sediment are stopped in the reservoir,which causes an earthshaking change on the coming water and sediment condition of lower reach and river bed evolution rule.Taipingkou water channel is the first sandy shoal with microbend bifurcation of the Three Gorges Project’s lower reach,which is impacted most by the Three Gorges,and the swale structure is adjusted remarkably so that the channel conditions are not stable,therefore the channel has been the “barrier” of the main line of C hangjiang river,which influences the comprehensive trafficabilit y of the main line of C hangjiang river,as well as to be the big stumbling block in harmonious development of regional economy.In order to achieve golden effect of “golden channel”,to promote the development of Changjiang River Economic Zone,the researc h on recent Taipingkou water channel is in urgent need so as to start the channel regulation work,improve the channel dimension of middle reaches of C hangjiang River and give play to the potential of C hangjiang River transportation.This paper bases on large amounts of measured data,employs two-dimension flow and sediment mathematical simulation,conducts an analysis on the Taipingkou channel’s character of river bed evolution and navigation obstacle,and proposes economic,effective and reasonable channe l improvement measure,which provides reference to subsequent treatment of this channel,the principal research results are:(1).After the impoundment of Three Gorges Reservoir,a newsilt-discharge condition has been formed.This paper makes an analysis of historical development,recent evolution of Taipingkou channel’s river bed and discusses the reach’s flow and sediment change rule,erosion and deposition of river bed,channel conditions’ change,forming reasons of shoal and their mutual re lation.(2).In this paper,a two-dimensional mathematical modelis established and verified,which is about 22 km long reach of the Chenjiawan to the Yuheping to predict the Taipingkou channel’s river bed evolution and developing trend of channel structure after the Three Gorges’ impounding so as to gain the result that south channel generally remains stable,north branch trends to an unfavorable direction as the continuous right shift of sedimentation in Yanglinji and the south branch get worse.(3).According to the already-built project and ready-to-build project,this paperproposes the channel regulation scheme targeted with extending“south channel-north branch”,and verifiestheirs feasibility of the two kinds of engineering layout of the scheme,meanwhile,combines with channel evolution trend and raises a second channel treatment scheme with more pertinence and breakthrough.(4).Contrasted with channel regulation schemes,the first scheme not only costs large amount of investment,manpower and material resources,but also the regulating effect is not very remarkable.Therefore,I suggest to select the second scheme which has more efficiency,effectiveness and mee ts the changing trend of the current channel as the follow-up treatment scheme.