The debris flow occurred on July 23

2009 at Xiangshui Gully of Kangding County in Sichuan province

caused 16 death

38 missing and serious loss of property.Xiangshui Gully is a right branch of the upper Dadu River

and the activities of historical debris flows are not clear in the last 100 years.Because of nearly a month continuous rain before

the sediments in the gully have been almost completely saturated in water

and the debris flow was triggered by a rainstorm on that day.This paper analyzes the formation conditions

disaster causes and characteristics of Xiangshui Gully based on the field investigation data and assesses its hazard comprehensively by application of grey correlation analysis combing with site-specific debris flow hazard quantitative assessment.The results show that it is still probable to break out middle and large scale viscous debris flow at Xiangshui Gully in the extreme weather.