Study On The Evolution And Regulation Measures Of Zhoutian Reach In The Middle Reaches Of The Yangtze River

The Yangtze River is China's largest river,the most important water main channel through the eastern and western regions,cargo volume exceeded 2 billion tons,which has been ranked 12 years in the global river first.The middle reaches of the Yangtze River from Yichang,down to the Poyang Lake Hukou,up to 900 km,is an important link to connect the upstream and downstream waterways.Maintaining the smooth flow of the Yangtze River channel will have a positive effect on promoting the social benefit of the Yangtze River golden water channel as soon as possible.However,in Zhoutian River,which is located in the middle of the Yangtze River,the pattern of the beach trough changes frequently and the channel condition is poor,which is always the focus and difficulty of the management of the middle reaches of the Yangtze River.Zhoutian River from the Haoxue waterway,down to the Ouchikou waterway,a total length of about 28 km,and is divided into Zhougongdi waterway and Tianxingzhou waterway by the Hufengou.The river is not only the beach beach scouring and changing,the mainstream swing uncertain,and the upper and lower waterway interaction,close relationship,so that the Zhoutian River has the characteristics of frequent variation of the Shangjingjiang River,and the significant correlation between the upper and lower reaches of the Xiajingjiang River,the evolution of the law is very complex;Recently,after the impoundment of the Three Gorges Reservoir,the change of water and sediment conditions has a dramatic effect on the evolution of the lower reaches of the dam,Zhoutian River is as the river that the earlier affected by the Three Gorges Reservoir,The continuous erosion of the "clear water" causes the waterway to worsen,impeding navigation problems,and seriously restricting the smooth flow of the middle reaches of the Yangtze River,the urgent need to carry out the law of the evolution of the rules and channel regulation measures to improve the Zhoutian section of the navigation condition.Based on Zhoutian River Channel Regulation Project in the middle reaches of Yangtze River as the backing,based on the hydrology and sediment and the measured topographic data,using statistical methods to analyze the characteristics of water and sediment and the variation characteristics;Based on the interrelated attributes of Zhougongdi and Tianxingzhou two rivers,the evolution law of Zhoutian reach is summarized and analyzed,forecasting the change trend;With two-dimensional mathematical model of water and sediment for the river water was simulated study to verify the results of the analysis of riverbed evolvement;On thebasis of the analysis of the river,the waterway regulation project of the river section is put forward;The three-dimensional mathematical model is used to validate and optimize the engineering scheme.The main conclusions of this paper are as follows:1.Zhoutian River within the two waterways up and down the relevance of strong,not only the interaction between the mainstream,and between the beach and erosion and silt decline;2.Jiaoziyuan marginal bank that affects the change of other beach shapes in the Zhougongdi waterway is the most important influence shoal,playing a connecting role in Zhoutian Reach;3.After the impoundment of the Three Gorges Reservoir,the river pattern of the Zhoutian River is relatively stable,but there are still some unfavorable changes in the local area;4.The existing waterway problem in the Zhoutian reach: the lack of water depth in the shallow transition zone of the Zhougongdi waterway,and the retreat of the Tianxingzhou bank,which makes the boundary of the channel unstable;5.The governance ideas of Zhoutian River: control the mainstream changes of the Zhougongdi waterway relaxation section,and avoid the influence of the water intake of the Yanjiatai irrigation station;stabilize the continental beach pattern of the transition section of the Tianxingzhou waterway;6.According to the research of the mathematical model of the remediation scheme,the infiltration of the dive dam dammer will not weaken the dam body's effect,but also to reduce the sedimentation of the upstream sediment of the dam to a certain extent.It is suggested to arrange a permeable area in Yanjiatai area,permeable area ratio of which is in the range of 10% to 20%.The research work of this paper is to explore the evolution law of the shoal in Zhoutian reach,analyze the development trend of river bed under the new water and sediment conditions,and study the control measures of the long straight transition stage with certain reference value and practical significance.