Soil mass domination in debris-flow disasters and strategy for hazard mitigation

Abstract

<p>The traditional view is that the formation of debris flow disasters mainly depends on precipitation, and the process of its runoff and confluence is a physical process that can be simulated by hydrological processes. However, based on the current phenomenon that the debris flow disasters concentrated in seismic zones and arid valleys and the existing research on formation and prevention of debris flow, our study found that in the mountainous areas where humans live, the slope and precipitation conditions are easy to meet the formation of debris flow hazards, and consequently the soil mass dominates the preparation, formation and evolution process of debris flow disasters. Thus, the catastrophic debris flow is a disaster which dominated by geological process and the characterization of the process requires more consideration of empirical models based on geological conditions. In addition, based on historical accounts of debris-flow disaster events, it found that debris flow occurrence is closely related to the impact of earthquakes and droughts. Applying this method, the debris flow susceptibility in the Southwest China has been predicted for 10 years from 2012, which realizes the dynamic prediction of regional debris-flow susceptibility and is helpful for timely prevention. Our results suggested that the prediction, early warning system and resilient alleviation of debris flow need to be determined by the mechanism and process which dominated by soil mass.</p>