Primary Research On Multi-effects Of River Flood And Channel Scouring And Siltation About Shore Projects

With the economic development since reform and opening-up, a large number of shoreprojects built in the river have been occupied a certain area, causing the elevation of river level,water resistance to change river flow patterns, water flow energy turning into turbulent kineticenergy, erosion around the building. And thus may have a huge impact on the building stability,riverbed evolution and slope stability. In another word, the proper layout of shore building playsan important role on the river flood, river stability, dike safety, water and transportation.However, previous studies about argument for the impact of shore projects and flood controlevaluation mostly carried out for individual projects. The studies on multi-effects of projectgroups are few and mostly to demonstrate the influence of shore projects on the water level andflow field but riverbed erosion. But in fact, the impacts of shore projects on the river flood controlare combined effects, which is with "quantity" or "quality" difference form the individual project.In this paper, analyzing by the generalized tank testing, Hydraulics and River Dynamics, themulti-effects of project groups on the river flood and erosion are studied and the results are asfollows:The construction of shore projects would have an impact on the local flow field ofengineering, water lever, water resistance and riverbed, particularly increase the multi-effects ofproject groups. For example, the construction of a single terminal may causes lower water velocityof upstream, higher water lever, lower water velocity and lever of downstream. Thus watervelocity at the front and lateral of terminal is increasing locally and the dividing line between thewater level increases and decreases has been formed. As for bed deformation, a scour hole isfinally made at the front and upstream of the terminal and the common deposition at downstreamside. However, after the construction of two terminals, the minimum water velocity at theupstream of Terminal I and the maximum water lever would increase. Long distance watervelocity decreases coastal zone would be shown between the two terminals and water levelboundary move to the downstream. As for bed deformation, scours and maximum scour depthwould decrease around the two terminals. The sedimentation intensity between the two terminalswould increase.The construction of terminals increases the flow composite roughness. Compared to the roughness of no project itself, the increasing degree of composite roughness is 16.52% for singleterminal and 66.09% for the two terminals. In a conclusion, the multi-effects of terminal groupscan not be ignored and they are related to the flow field, water level, flow resistance and channelchanges and the number of terminals, terminal spacing and size structure.