Analysis of debris-flow dynamics based on seismic signals: Insights from laboratory experiments and field monitoring

Abstract

Debris flow can cause severe damage due to its high velocity, large volume, and long transport distance. The monitoring and early warning system is one of the key approaches in debris-flow hazard mitigation. Monitoring and early warning equipment are easily damaged by debris flows, which directly affects the monitoring system. In recent years, environmental seismology has provided a new research method for debris flow monitoring and early warning due to the advantages of long-distance, non-contact monitoring and rich, dynamic information. However, we still lack essential understanding regarding the relationship between the basal force and physical properties of debris flow at the channel bed and the relationship between the impact mechanisms of the granular flow barrier and the generated seismic signal. We designed a series of flume experiments to analyze the distribution of base force and the link between the impact mechanism and seismic signals in geophysical flow. We examine the probability density function (PDF) of the basal impact force and establish a relationship between the PDFs distribution parameters and the geophysical flow's physical properties. We found that there are peak amplitude thresholds of the seismic signal that can distinguish between runup and pile-up mechanisms when considering engineering mitigation measures in the channel. Finally, by integrating laboratory experiments and field monitoring, we establish the relationship between seismic signals and debris-flow dynamics.