Analysis of sediment rating curve and sediment load for langat river basin

An analysis of suspended sediment and streamflow over a period of 12 months in three monitoring stations, FS1, FS2 and FS4, from the upstream to downstream of the Langat River was carried out.The statistical approach and examination of the physical process aim to provide a better understanding of the sediment flow characteristics.The objective is to evaluate the sediment rating curves to estimate the suspended sediment concentration (SSC), hence the seasonal and annual sediment load.Correlations improve when the streamflow lead sediment is discharged by one day.In addition, the concave sediment rating curve indicates resuspension of deposited materials in the river system during flood.A plot of SSC and flow duration curve shows the increase of sediment sources at the basin in the downriver direction and outliers are attributed to flash floods.Logtransformed linear regression of sediment concentration rating curve gives the best R 2 values and the lowest percent mean error for all stations.The total annual sediment load in the river basin upstream of FS4 is estimated to be 657,551 tonnes, where the monthly and seasonal variations are consistent with the monsoon period.Stations FS2 and FS4 have approximately the same sediment yield, but the concentration reduces downstream due to flow dilution effect.The model works well for the prediction of sediment discharge of regular flows but may overestimate annual sediment yield due to high flows.The present study contributes to more precise prediction of sediment loading in a river basin for related engineering application.