The Response Of Debris Flow To Soil Vertical Differentiation Factor In The Upper Reaches Of Min River

The upper reaches of the Min River is located at the edge of the western Sichuan Plateau.The debris flow activities in the area are characterized by different types,varying natures and complex disaster patterns.The reason is mainly due to the comprehensive influence of vertical differentiation of mountains.Soil is one of the three elements that characterize the vertical differentiation of mountainous areas.Its vertical differentiation has a certain relationship with debris flow activities.Firstly,the paper gave a general overview of the study area,analyzed the characteristics of debris flow activity,selected the clustering index,and used the K-means algorithm to classify the debris flow ditch.Then,Using ArcGIS software,the factors with high correlation with soil vertical differentiation were analyzed,and each factor was analyzed and numerically processed;finally,qualitative analysis was carried out on the two,and then the geo-detector model was used to analyze and summarize the coupling relationship between them.The main progress of this paper is as follows:(1)Through the analysis and summary of the debris flow characteristics in the area,244 debris flow trenches were selected,and the debris flow ditch was clustered into 6 categories by K-Means model,among which 1 type of debris flow ditch had the largest number,170;Combined with the risk analysis,susceptibility and development degree of debris flow ditch,it was concluded that the debris flow ditch in the area was mainly low-risk,low-prone and strong in young years;then the study area was divided into 22983 grids,and got the ratio of debris flow area in each grid.(2)Drew the distribution maps of soil,climate and vegetation in the upper reaches of Min River,and analyzed the vertical differentiation rules.According to the characteristics of soil,they were classified into 8 categories by ArcGIS,and the distribution of soils of various types was obtained.The area of meadow soil is the largest,which is 8704km2,accounting for 38.71%.According to the research results,eight soil vertical differentiation factors were selected firstly,and then the correlation between each factor and soil vertical differentiation was analyzed by ArcGIS.According to the size of sex,seven related factors such as land use type,solar radiation and stratum lithology were selected,and the regularity of each factor in the vertical direction was further analyzed.(3)Combined different types of debris flow ditch and soil vertical differentiation influence factors,analyzed the influence of vertical soil differentiation factors on debris flow activities;qualitatively study the debris flow activities and soil vertical differentiation influence factors,and analyzed the data.Preliminary conclusions,using the geo-detector model to analyze the coupling relationship between the two from a quantitative perspective,the correlation between the seven soil vertical differentiation factors on the debris flow activity,namely the land use type(0.033)and the elevation(0.032).),solar radiation(0.019),annual rainfall(0.017),formation lithology(0.016),slope(0.015)and vegetation coverage(0.012);finally,from the qualitative and quantitative perspectives,the vertical distribution of soil There was a large response relationship between the different impact factors and the debris flow activities.