Evaluation of the Sediment Trap Structure Performance in the Saddang Irrigation

Abstract

Irrigation canals require desilting basin to reduce sediment deposits in the main irrigation canals. The capacity of the Saddang River Irrigation Canal will be increased by 30% to accommodate long-term irrigation discharge needs. To optimize the ability of the desilting basin to trap suspended sediments, an evaluation was carried out using the 2-D finite-volume numerical method for hydrodynamic and sediment transport models. It solves the 2-D dynamic wave equations (the standard depth-averaged St.Venant equations) that are mainly used for river simulation. In addition, the diffusive wave solver is used for watershed runoff simulation and river simulation. The Community Edition SRH-2D model uses a flexible mesh that may contain arbitrarily quadrilateral and triangular cells. A hybrid mesh may achieve the best compromise between solution accuracy and computing demand. The SRH-2D Model solved variables include water surface elevation, water depth, depth averaged velocity, Froude number, and bed shear stress. Sediment Transport Model solved variables include sediment concentration, erosion and deposition, bed elevation, sediment transport rates, bed material D50 size, and bed material gradations. The optimization of the model is useful for improving the lining channel, flushing time period and the performance of the sediment trap.