Warning system for debris flow hazards at Sakurajima Volcano, Japan
We introduced a method of early warning system for debris flow by using point rainfall and an evacuation technique on debris flowby using a sensor of ground tremor and mobile phones. This method has been confirmed by field observations. Debris flows were observed in the Hase River and the Nojiri River of Sakurajima Volcano, Japan. By and large, going away from a valley, ground tremor caused by a debris flow becomes small and this phenomenon seems to be different from the volcanic activity. The spectrum of ground tremors observed in the outdoor experiments is very similar to that observed in debris flows from the active volcano. We have thus confirmed that the magnitude of discharge has a tendency to be in proportion to the size of ground tremor. By using a neural network computer program, we have been successful in estimating the hydrograph of a debris flow. We have found that observed frequency of ground tremor distinguishes between debris flowand clear water flow. The range of frequency is from 50 Hz to 100 Hz for debris flowand less than 50 Hz for clear water flow. Our trigger system of detecting volcanic debris flows can also detect the occurrence of non-volcanic landslides and snow avalanches among others.
debris flow disaster prevention early warning system evacuation ground tremor
M. Hikida M. Moriyama Y. Nagai
Department of Civil Engineering, Kagoshima National College of Technology, Kagoshima, Japan Department of Civil Engineering, Sojo University, Kumamoto, Japan Osumi Office of River and National Highway, Ministry of Land, Infrastructure and Transport,Kagoshima
国际会议
成都
英文
593-602
2007-05-17（万方平台首次上网日期，不代表论文的发表时间）