Development Characteristics And Risk Assessment Of Mine Debris Flow In Zhaojia Gully In The Southern Of The Qinling Mountains

The southern foothills of the Qinling Mountains are rich in mineral resources,and mine debris flows in the area account for a considerable proportion of geological disasters.With the continuous emphasis on the geological environment of mines in recent years,the prevention and control of mine debris flows in the southern foothills of the Qinling Mountains is also more important.The Zhaojia Gully in the south of Qinling Mountain is deep-cut and rich in slag sources.In addition,the Ministry of Water Resources has issued an abnormal weather warning since the first quarter of 2020.In order to ensure the safety of personal and property of local residents,the research on the development characteristics and risk assessment of debris flow in Zhaojia Gully mine is of great significance to the countermeasures and engineering design of disaster reduction and prevention.The main research results of this article are as follows:(1)Through field investigation and calculation,it is found that the Zhaojia Gully Debris Flow Gully Basin is about 1.295 km long,with an area of about 3.1km2,and an average longitudinal slope drop of about 307‰.More reserves.Combined with local hydrological conditions,Zhaojia Gully has the basic conditions for the formation of mine debris flow.(2)The Zhaojia Gully debris flow basin is divided into a source area(formation area),a circulation area and an accumulation area.The debris flow zoning results show that the provenance area mainly provides provenance and provides important hydraulic conditions for the formation of debris flow.The total provenance is about 54.2×104m3,and 5 slag piles account for 62%.The circulation area provides important topographic conditions for the formation of debris flow and there are some sources.Although the accumulation area is small but there are cultivated land and buildings,once a debris flow occurs,the hazard is greater.(3)On the basis of the basic characteristics of debris flow,according to the norms and reference to the empirical parameters of others,calculate the dynamic parameters of debris flow with an explosion period of 5 years,10 years,20 years,50 years,and 100 years.Combined with various parameter values,the Zhaojia Gully debris flow is determined according to the specifications as a rainstorm type,spoil type,gully type,water stone type,and rare debris flow.(4)Using the combination of game theory based on analytic hierarchy process and entropy value weighting idea to improve Liu Xilin's single-ditch risk assessment model,and then conduct a risk assessment on Zhaojia Gully debris flow.Compared with the original model,the results show that the risk assessment results of the improved game theory combination weighting model are more in line with the actual situation of Zhaojia Gully.The results are extremely low in the outbreak cycle of 5 years,10 years,and 20 years.1.It is a low risk under a 100-year outbreak cycle.The risk assessment method can provide some reference and reference for the risk assessment of debris flow in the south of Qinling.(5)Calculate the affected area based on the typical fan-shaped accumulation to determine the disaster-bearing body,combine the social,economic,and cultural indicators to make the vulnerability assessment,and then make a risk assessment.The risk assessment results show that the Zhaojia Gully debris flow in The 20-year outbreak cycle is low-risk,and the 50-year and 100-year cycle is moderate risk.The results are in line with the actual situation.Finally,according to the current development characteristics and risk status of debris flow in Zhaojia Gully,protection countermeasures are proposed and protection projects such as drainage ditches and retaining walls are designed.