Calculating debris flow density based on grain-size distribution

Abstract

Debris flow density is an important parameter, which reflects the genetic types of debris flow and determines fundamental properties. Debris flow density is usually calculated based on a certain part of the grain composition, using samples collected from deposits more or less long after the occurrence. These methods have two major flaws: the samples from deposits do not coincide with the grain composition of flow, and the used special part of the grain is artificially selected without physically sound basis. This paper proposes a new formula to calculate debris flow density based on analysis of fluid samples collected in Jiangjia Gully, which employs the grain-size distribution parameters that feature the full range of the grain composition.