Abstract:In Longquan County of Zhejiang Province,the geological environment is complex,the mountain disasters are serious.It is the high risk area of debris flow in Zhejiang Province.With the development of tourism and economy,it becomes urgent to study the characteristics and counter measures of debris flows in Longquan City.With the help of census,remotesensing and expertinquiry,146 gullys were surveyed, among which 96 was made by major investigation and 49 by typical investigation,46 potential debris flow dangers were identified.Through the survey and analysis,six characteristics of small watershed debris flow geohazard in Longquan City were summarized:wide distribution of debris flows in this area,breaking out mostly in typhoon and flood season,distributing mostly along fractures,suitable geographic conditions for the form ation of debris flow,high incidence of debris flow in lava,possible occurrence of debris flow in areas with both water loss and soil erosion and high-covered vegetation.Some corresponding count ermeasures were proposed to provide a rational basis for the prevention and treatment of debris flows in Longquan City.