Study On Formation Mechanism And Prevention Measures Of Debris Flow In DaMaYing Township,ShanDan County

The debris flow event in Damaying Township of Shandan County occurred in 2010,the debris flow overflowed the highway and related department governed it by developing the debris flow drainage project.According to the investigation,the probability of the debris flow occurring again is extremely high,which brings great potential threats to residents lives and properties of villages located in downstream of the gully.Therefore,it is very necessary to govern debris flows.This paper conducts an investigation on nature geography,weather,hydrology,regional geological environment and human activities of Damaying Township of Shandan County,calculates and evaluates the susceptibility and characteristic parameters of debris flow,puts forward relevant measures for governance,which is of great significance to the prevention and control of the debris flow disaster.The main work of the paper is as follows.First of all,through the field investigation of debris flow,this paper analyses the environmental geological conditions of debris flow gully in Damaying Township of Shandan County and finds out the debris flow gully originated from the former mountain belt of the northern Qilian Mountains.There is no fixed channel.Precipitation,snow and ice meltwater flows into the valley through the front slope of the mountain.Ditch shore collapse(collapse)collapse,gully bed debris,artificial deposits become loose solid source condition of debris flow.The annual average rainfall in the debris flow basin of damaying township is 328.2mm,which is mainly concentrated in summer.Aa result,there are conditions for the formation of debris flow in the topography,material source and water source.Secondly,the flow velocity of debris flow,the maximum volume of one time,the impact force of debris flow and the height of debris flow are calculated,which provide basic parameters for the prevention and control measures of debris flow.Finally,according to the actual situation of the debris flow in Damaying Township of Shandan County,two treatment schemes are proposed and the one which make the debris flow flow along the fixed channel to the Damaying River Valley is selected,because it is more reasonable,economical and effective.This scheme provided a scientific basis for the effective treatment of the debris flow in Damaying Township.By analyzing the causes of debris flow,calculating the characteristic value and evaluating the hazard degree of debris flow in Damaying township of Shandan County,this paper promotes the understanding of the hazard degree of debris flow and the formulation of the prevention mechanism,and strengthens the management of debris flow control.After the calculation,design and simulation of the risk coefficient,the consideration of debris flow prevention and control is improved,and the basic data of debris flow prevention and control mechanism is supplemented,which can provide certain reference significance for similar debris flow prevention and control in the future.