Vibrational characteristics of debris flow in Taiwan, The

Abstract

Debris flows have become a common disaster in Taiwan in recent years since the impacts of extreme weathers has been aggravated. To protect people from the debris-flow disasters, a monitoring and warning system was developed by Soil and Water Conservation Bureau (SWCB) in Taiwan. The rainfall-based criteria are used in Taiwan for debris flow warning. Different to rainfall measurement, the ground surface vibrational signal from a debris flow has been studied more widely in recent years. Sensors of geophone (short period seismograph) and broadband seismograph are commonly used for debris flow monitoring. In this paper, the signal analysis of debris flows was performed by calculating the vibrational energy. The comparison of the analysis results indicated that when the energy ratios of at least two of the axes are greater than 1.12, a debris flow is highly likely to occur. The starting point in the increasing trend of vibrational energy implied the possible warning time point for debris flow. Vibration examples of debris flow and earthquakes were also compared in this paper.