| China is a mountainous country,especially in the western region,mountainous area is widely distributed,the terrain is complex,the fault structure is developed,the earthquake activity is frequent,and the monsoon climate creates conditions for the formation of debris flow.In recent years,mudslide disasters have occurred frequently,posing a serious threat to the lives and property of the people.Because of its sudden,short-lived and destructive power,it has become an important factor restricting the development of the west.This paper relies on the “Geological Survey of Yecheng-Wuqia Region in Xinjiang province ” project of China Geological Survey,and takes Chaihe gully as the research object,combined with the results of field investigation and investigation,based on the investigation of domestic and foreign literatures,analyzes the debris flow in Chaihe gully.The developmental characteristics,the evaluation of the risk of the line,and finally the simulation of its motion characteristics.The main research contents of this paper are as follows:(1)The natural conditions of the study area were briefly analyzed;the engineering geological conditions of the study area were analyzed from the aspects of topography,lithology,geological structure,and hydrogeological conditions.The study area is generally an eroded and denuded mountain area.Affected by the fault structure,the weathering speed of the rock mass is accelerated,the structure of the loose slope deposits is destroyed,and adverse geological phenomena such as landslides in the basin are developed.In addition,rainfall mainly concentrated in April to August The development of debris flow provides favorable conditions.(2)The development characteristics of chaihegou debris flow are studied.According to the formation conditions of chaihegou debris flow,the chaihegou watershed is divided into clear water area,formation circulation area and accumulation area,and the impact characteristics of each section are introduced.The history of the debris flow disasters in Chaihegou was studied,the development stages and susceptibility of debrisflows were analyzed,the types and quantities of provenances in Caihegou were counted,the rainfall intensity parameters at three frequencies were designed,and P = 2% was calculated.The characteristic value of debris flow force is studied,and the phenomenon of debris flow blocking river is studied.(3)In order to study the movement characteristics of mudslides after different storm frequencies,numerical simulations were performed using Massflow software to obtain mudslides and mud depths and velocities under three rainstorm conditions.The simulation results were imported into a surfer for analysis,which verified the existence of two mudslides in the study area.At the point of plugging,the relationship between mud depth,mud velocity,velocity and time was established.(4)Based on the field survey data and the topographic map of the study area,the watershed area,the maximum rainfall for 24 hours,the length of the main ditch,the maximum outflow of debris flow,the maximum relative height difference of the watershed,the loose material storage,the average ratio of the main ditch,and the main ditch Based on the theory of extenics,based on extenics theory,the combined weighting of each of the 10 influencing factors such as bending coefficient,watershed cutting density,and length ratio of silt replenishment sections is used to obtain the weight of each evaluation factor.The topological model is comprehensively evaluated and compared with Liu Xilin's evaluation formula.The results are consistent,and the danger degree of debris flow in Chaihegou is moderate. |
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