A review on acoustic moni toring of debris flow

Debris flows and debris floods are processes that occur in high alpine regions with consequences on infrastructure and settlements. Recently, several studies have been conducted by the authors using a new approach to gather knowledge about debris flows using a combination of two acoustic sensors: seismic sensors and infrasound microphones. Both sensors have been individually used in a number of previous studies. But the potential combination of infrasonic and seismic sensors for monitoring natural hazards, which could take advantage of the benefits of both sensor technologies and the possibility of using this setup for early warning, has not been evaluated to date. As a consequence, in this study the most important characteristics of acoustic signals from debris flows monitored at different locations in the Austrian and Swiss Alps are summarized and possible interfering signals are presented. An approach of using this acoustic signal for early warning will be introduced and evaluated. In addition, the data will be compared with other measurements, such as flow depth, interpretation, verification, and validation of the seismic and infrasonic data.