Debris flow is composed of a wide range of grains. A comprehensive model of debris flow requires incorporating a variety of material rheologies. Though, the existing rheology in continuum models (e.g., Bingham fluid) is exclusively concerned with fine content up to clay-size grains, this does not really represent the nature of the matrix that incorporates coarse grains beyond the experimental capacity of rheology.

In order to find out a way to solve this problem, Prof. LI Yong of Institute of Mountain Hazards and Environment, Chinese Academy of Sciences (IMHE) and his team propose a general form of grain size distribution, which is satisfied well by various debris flows and by soils and sediments related to debris flows.

The research result provides a simple but quantitative method of predicting a potential flow through the source soils.

This research is supported by the Key Research Program of the Chinese Academy of Sciences (grant no. KZZD-EW-05-01), the National Natural Science Foundation of China (grant no. 40771010), and the National Key Technology Research and Development Program (grant no. 2012BAK10B04).

The paper entitled “A scaling distribution for grain composition of debris flow” was published in Geomorphology, 2013(192): 30-42, DOI: 10.1016/j.geomorph.2013.03.015.