Criterion for Deposition of Sediment Transported in Rigid Boundary Channels

Abstract

Lined channels are used in irrigation and hydropower systems with the object of minimising seepage losses and conserving the available head. Concrete tunnels are also used in sediment excluders and extractors to carry flows with high sediment concentrations. When sediment-laden water enters such channels, an important design requirement is that the sediment entering the channel should not deposit on the bed. This means that the sediment transporting capacity of such channels should be greater than or equal to the rate at which the sediment is entering the channel. Although the laws of sediment transportation for alluvial channels are fairly well known,enough information is not available concerning the sediment carrying capacity of rigid boundary channels. Since wash load transport involves negligible exchange of sediment particles at the bed, the problem of determination of maximum wash load transport without objectionable deposition is closely related to the above problem. There is thus need to study the sediment transport capacity of rigid boundary channels.