The Study of Riverbed Change and Bed-load Transport in the Middle Segment of the Batang Kuranji River

Abstract

Batang Kuranji is one of the biggest river in Padang City with catchment area of 202,7 km2. In the middle segment of this river have degraded significantly, especially in the downstream side of Gunung Nago Dam after the big flash flood in 2012. This also supported by the steep river slope of 0.017 and the activity of excavation of sand and gravel downstream of Gunung Nago Dam. Based on this, the authors are interested in examining the study of riverbed change and bed-load transport in the middle segment of the Batang Kuranji River, to determine the amount of sediment and changes in riverbed elevations that occur and analyse the location of proper building to reduce water damage. In conducting this research, researchers collected primary data, namely direct sampling in the field and secondary data from various relevant literature sources. In this study seven methods of calculating bed-load transport were used, including Meyer Peter Muller, Einstein, Einstein-Brown, Kalinske, Frijlink, Engelund and Hansens, and Van Rijn. Based on the results, there was a change in riverbed elevation, in the period of 2011 to 2013 there was a scour volume of 902,527 m3 greater than the sediment volume of 193,435 m3 where the sediment occurred was only 21.43% with the deepest scour 10.52 m. Kalinske sediment transport method has the closest value to manual calculation. The comparison between Kalinske method and manual calculation respectively; 0.056 m3/day and 0.187 m3/day in S12 sample; 0.312 m3/day and 0.554 m3/day in S23 sample; and 0.020 m3/day and 0.081 m3/day in S33.