Research On The Diversion Model Of Discharge And Sediment With The Erosion And Deposition Of River

River diversion is a familiar form of alluvial river, which is often caused by ait and chur. At the same time, emissary and headwater channel also is a familiar form of river diversion. The evolvement of Diffluence River is the more complicated than Single River, because the diversion's thing is changed with channel's distortion. The river diversion is the general reflection of a good many factors, which mutually influence and adjust. In particular, when main channel occurs scouring-silting change, which causes the movement of water, sediment, and river bed in river system, the diversion will more be changed, with the study on division of discharge and sediment been further into, some practical engineering problem are solved. However, such researches basically neglect a fact that flow structure near diversion gap charge because of distributary's drawing water. Especially study on the influence of the erosion and deposition of Riverbed to diversion of discharge and sediment important guide role to the planning of drainage area developing and programming, and theoretical value is significant. The paper consists of three parts to focus the above problems.The first part is about water level variation according to different riverbed deformation in river channels of several kinds of cross section shape analysis. In this paper, water level variation according to different riverbed deformation in river channels with different kinds of cross section shape is analyzed. With calculation of simplified channel models, the relation between water level change and channel erosion is presented.The second part is about influence to diversion ratio because of the water level variation in mainstream. The erosion and deposition state of mainstream may change the elevation of the river bottom, so as to change the diversion of flow and sediment. But little work is done about this field. Based on the result of formers', this paper works on the influence of the main stream (whether erosion or deposition) to the diversion of flow and sediment mainly. Further study of the evolution law and the factors of river's diversion will be useful to revolve the relationship between Yangtze River and Dongting Lake. The quantificational equation is developed to describe the relation between mainstream riverbed erosion& deposition and the variation of diversion ratio of flow and sediment the equation is verified with the field data of diversion change of the three diversion in Jingjiang Riverafter the river cutoff.The third part is about practical application. The most important influence is the distributary channel's deposition to irrigation channel. So in this chapter, through distributary channel's deposition computing the irrigation channel lied to the work of water transfer from the Yangtze River to Hanjiang in Jingjiang Reach, the model is modified to satisfy the work's demand in precision and appliance.