Progress in debris flow modeling

Abstract

The processes of the two major types of debris flow initiation; the bed erosion type and the landslide-induced type, are discussed and the methods to analyze the respective phenomena are introduced. Especially for the landslide-induced type, a new model of liquefaction of the slid earth mass while in motion is introduced. The earth mass is liquefied at the bottom without water supply from the outside and this liquefied layer gets behind the mass as a following debris flow. The reviews of previous investigations on the mechanics of developed debris flow confirms that the two-phase model is influential, in which debris flow consists of the mixture of two continuum media of fluid phase and solid phase. Using this model, developed debris flows are classified into three types from the point of the dominant stresses within flow. The characteristics of the respective types of flow such as the solids concentration distribution, the velocity distribution, the equilibrium sediment transport concentration are given. © 2007 Springer-Verlag Berlin Heidelberg.