Study on Evolvement of High Beach and Deep Channel of Reservoir in the Sediment-Laden Rivers

Abstract

According to datas of Sanmenxia Reservoir and physical model test of Xiaolangdi Reservoir during later sediment retaining period, the paper study evolvement of high beach and deep channel of reservoir in the sediment-laden rivers. The results show that: 1The evolution of high beach and deep channel is as follows, firstly, beach and channel increase synchronously , and then scour happens in channel. Channel scour and scour amount is crucial to form high beach and deep channel. 2It is found that tributaries were equivalent to the horizontal extension of mainstream riverbed. The deposition process of tributary is closely related to many factors of natural topographic condition, deposition morphology of mainstream at the confluence area of mainstream and tributary and so on. The cross-section of tributary kept uplift horizontally, and sand bar has formed in some tributary estuary. 3Rainfall erosion formed in flood period is beneficial to forming hyper-concentrated flow, to a certain extent; it can recover channel storage capacity, and play an important role on utilizing long-term comprehensive benefits. Studying evolvement of high beach and deep channel can supply some technical supports for regulating operational mode of Xiaolangdi Reservoir during later sediment retaining period and prolonging service life.