Linking Dynamic Parameters and Seismic Signals of Granular Flows in Different Flow Regimes: An Experimental Assessment of Effects of Particle Composition

Abstract Geophysical flows, governed by particle composition and channel slope, exhibit distinct kinematic properties and seismic responses under different flow regimes. This study examines the impact of particle composition on granular flow dynamics and seismic signal generation under various flow regimes using flume experiments under dam break conditions. By varying particle composition and flume inclination angles, we investigate the kinematic properties, seismic responses, and the relationship between flow regimes and seismic signal characteristics. The results reveal that particle composition significantly affects flow dynamics, with peak velocity exhibiting a non‐monotonic dependence on particle size, and an optimal proportion of large particles maximizing mobility. Seismic signals, including peak amplitude and power spectral density, increase with larger particle sizes and steeper inclination angles, indicating a strong coupling between flow dynamics and seismic responses. A two‐segment positive correlation between seismic signals and collisional stress highlights the role of flow regimes, with particle‐ground impacts during intense collisional interactions dominating seismic signal generation, we then introduce a dimensionless amplitude parameter and establish a unified correlation with the Savage number across flow regimes. This study advances the understanding of granular flow dynamics and seismic signatures, providing a framework for interpreting seismic data in debris flow monitoring and hazard assessment. Future work to explore the interplay of frictional and collisional mechanisms to refine models of granular flow behavior and physical interpretation of seismic data is warranted.