The Development of  Total Bed Material Transport Rating Curve for Rivers in Malaysia :  Case Studies of Pari River, Kerayong River and Kulim River

Development, which takes place in river catchment areas, will result in discharge and bed erosion increment or scouring and deposition. The matter stated above will result in the unstability in the river channel. When this happens, there will be failures to the riverbank or in the river protection structure and reduce the channel capacity to flow the flood to downstream. Therefore, it is necessary to predict the river channel stability that will happen due to the existing development or the one which will take place in the future in a river catchment area.

This study covers three rivers, which are Pari River in Ipoh, Perak, Kerayong River in Kuala Lumpur and Kulim River in Kedah. This study involves the collection of hydrological data such as rainfall data, river stage data, the discharge and also data related to erosion and deposition like the river bed sediment load, suspended load and river bed material. Observation was also conducted to identify the changes of the riverbed in a few locations of these rivers. The data collected were analyzed to assess the sediment transport equation in order to predict the sediment rate that is very close with the observed sediment rate.

The new equation for sediment transportation for the rivers in Malaysia is also formed based on the observed data. It was found that the Yang equation is the best followed by the Graf equation. Base on the equations that are stated above sediment transport rating curve can be developed in any locations of a river. The information of the sediment transport rating curve together with the sediment information connected to the design of hydrograph information generated from RORB model can be used in sediment transport models such as HEC-6 and Fluvial-12 to predict the river channel stability due to the existing development or in the future in a river catchment area. Hence, engineers can take some possible early actions to protect the riverbanks or the river protection structures from any failures. The maintenance works of the river could be run efficiently with the minimum cost.