Sediment transport processes in the Sangu River basin using a rainfall-sediment runoff model for sustainable river management

Abstract

The Sangu River, whose basin area is about 3600 km2, conveys a huge volume of sediment laden water during the monsoon, which decreases the river's capacity, causing flooding, channel change, and navigability problems. In this study, a basin-scale rainfall-sediment runoff (RSR) model was used to analyse the sediment transport in the Sangu River. Simulations were conducted for the year 2011, and the results were validated in terms of suspended sediment concentration. The simulation results show deposition trends particularly in the lower and middle reaches, and that nearly 7.5 × 105 m3 of sediment annually discharges to the Bay of Bengal. The simulation results also show the tributaries actively produce sediment, which results in sediment deposition in downstream channels. The analyses also find that the implementation of check dams in the upstream area significantly reduces sediment deposition in the downstream area. These findings offer valuable insights for the development of sustainable sediment management strategies.