Enhancing disaster mitigation through sediment transport modelling – Development of natural based solutions for the future

One of the key causes of floods is the reduced river storage capacity due to sedimentation. In this context, an oxbow lake currently functions as a retention pond, serving as an alternative nature-based solution (NbS). However, because retention ponds are highly susceptible to sediment accumulation, it is crucial to undertake a comprehensive study to develop effective strategies for managing flooding and sedimentation. This study aimed to establish a sediment rating curve and a sediment transport model for the Krueng Peuto River. The sediment rating curve, which describes the relationship between flow discharge and sediment discharge, is a crucial component of the analysis. In this study, sediment transport was modelled using the HEC-RAS 6.1 application. This application is capable of dynamically updating and more accurately approximating the channel morphology as the simulation progresses,, making it very useful for long-term analyses of riverbed morphology changes due to sediment transport. The results indicated that the sediment shear stress was greater than the critical shear stress (τ0 > τc), confirming that sediment transport occurs in the Krueng Peuto River. The sediment rating curve showed the following polynomial regression equation obtained of Qs = 0.0142Qw2 − 4.485Qw (upstream) and Qs = 0.0093Qw2 + 4.653Qw (downstream), with a coefficient of determination of 0.9957 (upstream) and 0.9995 (downstream), and Qs is the sediment discharge and Qw is the water discharge respectively. The modelling of sediment transport also revealed significant changes in the channel bottom. These findings have practical implications for flood risk management, Offering valuable insights for relevant stakeholders to develop strategies aimed at preventing and mitigating the adverse effects of sedimentation in the area.