Author(s): Behnam Balouchi; Ayda Mirzaahmadi

Linked Author(s): Behnam Balouchi

Keywords: Sediment transport; Climate change; 2D morphodynamic modeling; Acceleration factor; Computation time

Abstract: Sediment transport significantly impacts the sustainability of hydropower dams and river systems. In complex rivers, such as braided rivers with fine sediment sources, sedimentation can reduce reservoir capacity, threatening long-term dam operations. Climate change further influences the sustainability of dams, making the evaluation of future climate scenarios essential for effective water resource management. However, 2D morphodynamic modeling, crucial for understanding sediment transport in these systems, becomes time-intensive, especially when combined with long-term climate projections (50-100 years). To make such modeling feasible, an acceleration factor (AF) can be applied to reduce computation time, though it introduces potential errors. This study evaluates the effects of various acceleration factors on a complex braided river, aiming to identify a trend that optimizes accuracy while minimizing computation time. While the results showed variability across the three evaluated cross-sections, a comparison of bed elevation differences and total net errors across the entire domain indicates that AF=30 provides the closest match to the reference model. This study highlights that while using acceleration factors can effectively reduce computation time, their impact on accuracy may potentially vary depending on river conditions and other influencing factors. These variations reflect the inherent complexity of braided rivers and the potential influence of instabilities. Therefore, careful selection, validation, and consideration of these factors are essential to ensure reliable modeling results. Future studies should explore these aspects further to enhance understanding and model robustness.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P2046-cd

Year: 2025