Study On Navigation Impact Of Bed Scour Along The Lower Reaches Of Li Ze Hydropower Junction Project

Construction and operation of Hydro Project，not only can be formed reservoirs inthe upstream，through the water storage elevation river upstream water level，increasechannel depth in the upstream to achieve the purpose of improving the conditions ofthe upper reaches of navigable，and economic benefits can be obtained through powergeneration. However，the construction of reservoirs in rivers，downstream channel ofreservoir is often one-way erosion，leading to the river bed deformation so has a directimpact on the channel depth，bring many factors of instability to the downstreamnavigable. In this paper，we will make a preliminary study on downstream river scourof Lize Hydropower，Draw the following main contents:(1)analyzed the change of river runoff to the sediment conditions and theevolution of river after Lize Hydro-junction built,and combination of the hub reachesof the river bed boundary composition,to predict the evolution trend of the damdownstream riverbed.(2)Through the the Lize hub model erosion test, analyzed the data of local scourfor dam downstream.(3)used the theory of impact crude layer of gravel and sand to estimates riverbedultimate scour depth, calculation results show that the hub downstream river erosioncut a greater depth, typical section scour depth up to3.87m.(4)Established a two dimensional flow and sediment mathematical model of thehub downstream river.Preliminarily calculated erosion cut of downstream of theriverbed after the hub built.The flow rate, water level and riverbed topography of thetypical sections were analyzed and calculated.