Author(s): Takahiro Itoh; Satoshi Tagata; Takahisa Mizuyama
Linked Author(s): Takahiro Itoh
Keywords: Debris flow Detection LVP LP UAV
Abstract: Various kinds of sensors for debris flows detections have been proposed such as wire sensor, acceleration sensor and so on. In Europe, a geophone that is based on a vibration meter is usually used though the applicability is not confirmed for debris flow detection in Japan. A wire sensor is still now used for debris flow detection in Japan because of easy maintenance for disconnected wires. Sakura-jima Island is in southwest of Japan, and many debris flows occur by rainfall and falling ash deposition after eruptions. An LVP sensor has been developed by authors and installed there for continuous detection of debris flows and modified based on technical information obtained by maintenance after debris flow events. Debris flow occurrences have been continuously detected by combination of a wire and an LVP. In the island, there were small landslide event on 19th August 2021. Sediment transport and related movements due to debris flows were detected after small landslide. Those movements were monitored using an LVP and differences of the bed elevation by a laser profiler (LP) with an unmanned aerial vehicle (UAV). Present study shows that sediment due to the landslide could dam up the bed sediment and those could be transported by several debris surges through those monitored data.
Year: 2025