摘要：Gully-type debris flow induced by high-intensity and short-duration rainfallfrequently causes great loss of properties and causalities in mountainousregions of southwest China. In order to reduce the risk by geohazards, earlywarning systems have been provided. A triggering index can be detected in anearly stage by the monitoring of rainfall and the changes in physicalproperties of the deposited materials along debris flow channels. Based on themethod of critical pore pressure for slope stability analysis, this studypresents critical pore pressure threshold in combination with rainfallfactors for gully-type debris flow early warning. The Wenjia gully, whichcontains an enormous amount of loose material, was selected as a case studyto reveal the relationship between the rainfall and pore pressure by fieldmonitoring data. A three-level early warning system (zero, attention, andwarning) is adopted and the corresponding judgement conditions are defined inreal time. Based on this threshold, there are several rainfall events inrecent years have been validated in Wenjia gully, which prove that such acombined threshold may be a reliable approach for the early warning ofgully-type debris flow to safeguard the population in the mountainous areas.
