Influence of Particles Fall Velocity, Archimedean's Force,and Depth of Debris Flow on a Relationship between Ultimate Density of Debris-Flow Mass and Channel Slope

Based on theoretical studies, ambiguous dependence of ultimate density of debris-flow mass on channel slope (debris flow path) and possibility of discontinuous increase of debris-flow mass density, when critical value of channel slope is exceeded, have been established. This allows to develop methods for calculating changes in characteristics of debris flow as it moves in a mountain valley and on a fan, to assess the effects of confluence of debris flow with surface and (or) underground water feeders, to develop optimal measures to reduce damage caused by debris flows by active impact on the rheological characteristics of debris-flow mass, to assess the risk of economic activity in debris-flow dangerous areas, and to develop optimal measures to reduce damage caused by debris flows.