Hazard assessment of a catastrophic mine waste debris flow of Hou Gully, Shimian, China

On July 4, 2013, a substantial disastrous debris flow occurred in the Hou Gully in Shimian County, China. The Hou gully belongs to mine waste debris flow, which seriously threatens a large number of traffic facilities, factories, farmland, and residents located in the accumulation area. This paper took the Hou gully as an example and aimed to describe a typical mine waste debris flow, analyze the formation conditions, calculate the static and dynamic parameters, simulate the movement process, and evaluate the hazard. Distribution characteristics of slag were interpreted using the method of remote sensing and field investigation. FLO-2D model was chosen to simulate the movement process of debris flow in Hou gully under different recurrence period. According to the maximum momentum and maximum accumulation depth obtained by numerical calculation, the classification standard of intensity was established for mine waste debris flow. The occurrence probability and intensity of mine waste debris flow as critical factors to classify the hazard of Hou gully. The study process of this paper are conducive to a better understanding of the formation condition, movement characteristic, and hazard scope of mine waste debris flows induced by intensive rainfall. The hazard assessment map of Hou gully can provide a scientific basis for reconstruction and mitigation projects in the future.