Fuzzy comprehensive evaluation of debris flow in Matun village, Laomao Mountain area, Dalian city

A giant debris flow occurred in the Laomao Mountain area of Dalian city on July 27, 1981, which caused considerable losses of human lives and damages to properties. The average precipitation of Dalian has increased in recent years as compared with the annual mean precipitation. Increased and concentrated rainfall indicates a high possibility of debris flow outbreak in the Laomao Mountain area. The topography and material conditions of the debris flow gully in Matun village in Wafangdian city, Wanjialing town, Laomao Mountain area lead to the development and occurrence of mudslides. This study analyzed the development conditions of the debris flow gully in Matun village and conducted a risk evaluation of the debris flow gully by analytic hierarchy process and fuzzy comprehensive evaluation based on field survey in the study area. The results indicate that the debris flow gully in Matun village is highly dangerous, and debris flow occurs during heavy rainfall. In addition, the breakout of debris flow can threaten human life and property.