RISK ASSESSMENT AND DIFFERENTIAL STUDY OF DEBRIS FLOW IN DIFFERENT CHANNEL TYPES

It is of great significance to put forward corresponding prevention and control strategies and measures for the disaster-causing characteristics of debris flows in different channel types for the prevention and mitigation of debris flows. In this paper,the basic parameters of 16 different types of debris flow gullies were obtained through field investigation,testing and UAV aerial surveying,and their motion parameters were evaluated by numerical simulation combined with field investigation,in order to analyze and study the risk of debris flow in different gully types and their main influencing factors. The main conclusions include: (1)As the channel changes from a wide and gentle type to a narrow and steep type,the flow velocity in the debris flow runout area generally increases gradually,while the debris depth gradually decreases; (2)The burial hazard and impact hazard are closely related to the debris depth and flow velocity in the runout area,respectively; (3)Wide and gentle debris flow gullies are mainly prone to burial hazards,and it is advisable to adopt a prevention and control strategy of "blocking as the main approach,and drainage as a supplement"; The narrow and steep type is mainly prone to impact hazards,and it is advisable to adopt a prevention and control strategy of "drainage as the main approach,blocking as a supplement"; The transition type can choose prevention and control strategies according to its specific risk characteristics and local conditions. The research results can provide new ideas and a basis for disaster prevention and mitigation of debris flows in different types of channels.