A study of sediment transport and sedimentation potential of the proposed Timah Tasoh western diversion canal

Abstract

This study was conducted on a Timah Tasoh Western Diversion Canal is to determine sediment transport and an area with potential for sediment. This canal is being built along 22.5 km from the dam until Kuala Perlis River, inclusive of 750 m of tunnel. Along this canal, there are some points of the river station. The river station points are 22450, 18000, 12800, 8900, 4800, 3050 and 0. In this study, the objectives are to study sediment and erosion potential along the Timah Tasoh Western Diversion Canal using HEC-RAS model and to stimulate short term and long term sediment transport (erosion and deposition). The data that is required for this study are i.) geometric data (size structure of the building canal), ii.) the sediment data (size of stones and the percentage of the size of the stones at all point in the river station) and iii.) hydraulic data (used a steady flow type). All these data were provided by the Department of Irrigation and Drainage and from the contractors involved in the Timah Tasoh Western Diversion Canal project. Once all the data are entered, HEC-RAS will compute and identify the areas where there are erosion and sedimentation. From the analysis and simulation that have been conducted, the velocity indicated of critical erosion occurred in river station 22450 and station 18000 happened because of the highest value of water velocity, the types of soil conditions and the types of geometry of the canal. From river station 12800 until river station 3050, the sediment condition is transport as bed load and transport in suspension. The deposition is occurs at river station 0.