ABSTRACT
Sediment transport measurements at the inflowing rivers into reservoirs which are located at the mountainous catchment area have been always a daunting task. However, to meet the continues requirement on reservoir sedimentation monitoring and management initiatives, Total Sediment Load (TL) rating curves are developed mostly based on low flow data and TL equations area adopted to give reliable prediction for medium to high flow data. However, with the present state of knowledge, the selection of best TL equation for natural rivers remains a major doubt among engineers and practitioners. Thus, the present study attempts to evaluate applicability of the 10 existing TL equations to predict the sediment rating curves specifically for 2 inflowing rivers namely Senang Berangan River and Kenyir River into Kenyir Reservoir which is the largest man-made reservoir in Peninsular Malaysia. A total of 48 sets sediment and hydraulic data which covers low to high flow ranges were obtained from Sinnakaudan & Abdul Razad (2014) and adopted in the analysis. The study streams data encompass wide range of flow discharge (0.034 m3/s–23.96m3/s) with diverse particle size ranging from fine sand to boulder size of bed material (d50). The accuracy of existing equations was assessed by discrepancy ratio (DR) analysis whereby predicted and measured TLs were compared and accepted if the ratio is within the acceptable range from 0.5–2.0. It was found that Shen & Hung (1972) and Sinnakaudan at al. (2010) equations can predict more than 10% of data for coarse bed river. However, Shen & Hung (1972) shows consistency in prediction for both river morphologies. As such, it was adopted for TL rating curve development for the said rivers.
