Abstract: Debris flow is one of the most common geological hazards in mountainous areas. It is a special fluid containing large quantities of fine, coarse or gravel sized particles that are formed by the precipitation in synclinal gullies or back slopes. Debris flow has the characteristics of cooccurrence, periodicity and mass occurrence. The cause analysis of debris flow is fundamental to the of preventing and controlling debris flow hazard. This paper presents the Jiangjiatun debris flow in Renhe Village of Guanyang County in the mountainous area of northern Guangxi. The cause of debris flow in this area is analyzed based on the topographical features, stratigraphic lithology, geological structure and meteorological conditions. The results show that the steep terrain, loose and weak lithology, fault zone, quake lake caused by ancient landslide and short period of heavy rainfall are the main factors causing the mudslide.

Key words: Mud Flow, Geological Hazards, Formation Mechanism