Publication Date:
2018-08-31
Description:
Gully-type debris flow induced by high-intensity and short-duration rainfall, frequently cause a great loss of properties and causalities in mountainous regions of Southwest China. In order to reduce the risk by geohazards, early warning systems have been provided. A triggering index can be detected in an early stage by the monitoring of rainfall and the changes in physical properties of the deposited materials along debris flow channel. Based on the method of critical pore pressure for slope stability analysis, this study presents critical pore pressure thresholds in combination with rainfall factors for gully-type debris flow early warning. The Wenjia gully, which contains an enormous amount of loose materials, was selected as a case study to reveal the relationship between the rainfalls and pore pressure, which can be used as a combined warning threshold. A three-level early warning system (Zero, Attention, and Warning) is adopted and the corresponding judgement conditions are defined in real-time. Based on this threshold, several rainfall events in recent years have been validated to prove that such a comprehensive threshold may be a reliable approach for the early warning of debris flows to safeguard the population in the mountainous areas.
Electronic ISSN:
2195-9269
Topics:
Geography
,
Geosciences
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