Temporal dynamics and threshold behaviors of suspended sediment transport in the Abukuma River, Japan
3月 20th, 2026
Sheikh Hefzul Bari, Yoshiyuki Yokoo, Chris Leong
Received 9 October, 2025
Accepted 27 December, 2025
Published online 20 March, 2026
Sheikh Hefzul Bari1), Yoshiyuki Yokoo1)2)3), Chris Leong4)
1) Graduate School of Symbiotic Systems Science and Technology, Fukushima University, Japan
2) Hydrogen Energy Research Institute, Fukushima University, Japan
3) Institute of Environmental Radioactivity, Fukushima University, Japan
4) Linkage Project, Research Institute for Humanity and Nature, Japan
Quantifying suspended sediment (SS) dynamics remains a key challenge in river management, often hindered by low-frequency sampling. The present study addresses this issue by employing high-frequency turbidity data to analyze multi-scale SS transport in the Abukuma River, Japan. Our findings reveal a dominant dual-phase transport regime: extended periods of low concentrations interrupted by short, high-magnitude events. Overall patterns indicate shifts between supply-limited and transport-limited conditions. In spring, snowmelt and early rains efficiently mobilize fine sediments, while typhoon season rainfall pushes the system to its transport capacity, followed by sediment depletion. Extreme hydrological events, particularly in late summer and autumn, disproportionately govern the annual sediment budget, contributing nearly half of the total load and underscoring the system’s strong response to extreme events. We identified a critical discharge threshold of approximately 500 m3 s–1, beyond which coarser sediments, likely sand, contribute substantially to the total suspended sediment load. This threshold supports a novel, threshold-based sediment rating curve, offering a more realistic approach for estimating sand transport during high discharge events. By combining high-resolution data with a process-based threshold framework, this study enhances our ability to characterize complex sediment dynamics and provides valuable insights for effective river and watershed management.
Copyright (c) 2026 The Author(s) CC-BY 4.0