Modeling Sediment Deposition in Rivers Through Computational Fluid Dynamics

Faizatus Sholikhah (Universitas Islam Majapahit)
Diah Sarasanty (Universitas Islam Majapahit)
Erna Tri Asmorowati (Civil Engineering, Faculty of Engineering, Islamic University of Majapahit, Indonesia)
Albi Syah Yulviano (Civil Engineering, Faculty of Engineering, Islamic University of Majapahit, Indonesia)
Nor Muhammad (Civil Engineering, Faculty of Engineering, Islamic University of Majapahit, Indonesia)

Jurnal IPTEK
Vol 30, No 1 (2026): May

Sedimentation in irrigation canals significantly reduces operational efficiency and agricultural productivity in tropical monsoon regions. This study applied three-dimensional computational fluid dynamics (CFD) to analyze sediment deposition patterns in the Pakal River affecting the Bareng Irrigation District, East Java, Indonesia. The integrated approach combined HEC-HMS watershed modeling with ANSYS Fluent CFD simulation to evaluate sedimentation under design flood conditions (20-year return period).Design discharge was determined as 30.4 m³/s using the Modified Haspers-Weduwen method. CFD simulation revealed severe deposition totaling 2,200 m³ per design event, distributed across four distinct zones driven by weir backwater effects, bend circulation, channel expansion, and insufficient transport velocity. Model validation demonstrated strong performance (NSE = 0.84 for velocity, 81% spatial agreement for deposition). A critical finding is that low design discharge creates widespread subcritical flow conditions, resulting in more severe deposition than higher flows.The validated methodology provides a replicable framework for evidence-based sediment management in resource-constrained irrigation systems across tropical regions, with broader applicability to climate adaptation planning and infrastructure resilience assessment.