Model Tests of Catastrophic Initiation Mode and Transport Mechanism of Viscous Mudflows

Most previous studies on the initiation mechanism of debris flows have achieved some significant results by means of traditional linear methods, statistical analyses, and qualitative and single-factor analyses. In fact, however, a large number of field observation analysis indicate that the initiation of debris flows may be a complicated nonlinear process subject to many influencing factors, with its initiation mode showing typical and complex characteristics such as sudden happening and slow happening and so on, which we could not explain clearly till now. In other words, if the initiation conditions could be regulated and controlled, the prevention and control of debris flows should achieve the practical effect. Based on catastrophe theory, the characteristics and mechanisms of the initiation, transport, and sedimentation associated with viscous mudflows, which can be taken as representative of natural debris flows, are analyzed, described, and verified using flowing model tests on the well-designed test apparatus. The results show that not only does the initiation mode of viscous mudflows belong to the slow-starting mode, but also its transport mechanism is in accordance with the general characteristics of the cusp catastrophe model. This is of great significance not only with regard to the forecasting and controlling of viscous debris flows that occur frequently in mountainous areas, but to the enriching of the nonlinear theoretical system of debris flows initiation mechanism as well.