Sedimentation behind barrages and oblique river flow

摘要

The waterways of many barrages are larger than required, due to overestimation of the design flood. The barrage gates are not completely opened except during the passage of the design flood, causing deposition of sediments and formation of shoals in the barrage pond. This results in the development of an oblique approaching flow towards the barrage and an increase in scouring due to a constricted waterway on both the upstream and downstream sides of the barrage. This paper presents examples of the present situation of sedimentation behind barrages and the incidence of oblique river flow, based on images obtained from the "Google Earth" virtual world model.