DESIGN OF NON-WIDE CANALS FOR SEDIMENT TRANSPORT. CASE STUDY OF SUNSARI MORANG IRRIGATION SCHEME, NEPAL

摘要

Canal design for sediment transport requires the use of sediment transport predictors. The predictors are derived for a small range of flows and mostly considered for wide canals. The use of these equations in irrigation canals needs some adaptation. In this study we have used a depth-averaged logarithmic velocity distribution in a canal section to compute the sediment transport rate for different predictors under a different range of hydraulic and sediment characteristics. The predictability of the predictors was improved when tested with the selected Brownlie data for rectangular non-wide canals. A rational canal design approach is proposed that uses the sediment transport predictors after applying a correction. The proposed approach has been tested under changing water flows and sediment concentration using the mathematical model SETRIC. The field data of secondary canal S9 of the Sunsari Morang Irrigation Scheme in Nepal have been used. If the canal had been designed with the proposed method there would have been less deposition in the canal network. Copyright (C) 2014 John Wiley & Sons, Ltd.