Research On Identification And Distribution Characteristics Of Landslide Group In Chenghai-Binchuan Fault Zone Based On Object-Oriented

Landslides pose a huge threat to people's life and property safety.Thus,accurate identification of landslides is the basis for detailed feature analysis of landslide disasters,stability evaluation and early identification of hidden dangers.It has important theoretical and practical implications for the development and implementation of regional disaster prevention,mitigation and relief work.In this paper,the landslide in the Chenghai-Binchuan fault zone is taken as the research object,and the types of geological hazards in this area are analyzed in combination with the results of field investigation.Using GF-6 image data and DEM data,an object-oriented classification method is adopted.After distinguishing vegetation based on vegetation coverage and visual interpretation,combined with the method of identifying landslides with features such as spectrum,topography,texture,geometry,etc,a landslide identification feature rule set was established to identify landslide groups in the Chenghai-Binchuan fault zone.Check the landslide point according to the interpretation result.Based on the identification results,Arc GIS was used to analyze the spatial distribution of landslides in the Chenghai-Binchuan fault zone in terms of distance from the fault zone,east and west walls of the upper and lower sides of the fault,stratigraphic lithology,slope,slope aspect,elevation and distance from the river system.Distribution characteristics are analyzed.Finally,the engineering geological characteristics of two typical landslides,Longtan landslide and Xiayuan landslide in the Chenghai-Binchuan fault zone are analyzed,and their occurrence mechanism is analyzed.The main research results are summarized as follows:(1)There are many geological disasters along the Chenghai-Binchuan fault zone,mainly landslides,debris flows and collapses,and there are three typical deep-seated gravitational slope deformation(DSGSD)distributed in the area,each deep-seated gravitational slope deformation(DSGSD)develop a series of geological disasters developed in Shangdu,and it has obvious stepped landform and huge volume.Among them,DSGSD in Zhaizi Village is the most typical.(2)The mountainous area on the eastern margin of the Jinguan Basin at the northern end of the Chenghai-Binchuan fault zone was selected as the test area,and the landslide groups were identified and a set of landslide identification rules was established.A total of 13 landslides in the mountainous area on the eastern margin of the Jinguan Basin were identified.The total area of landslide correctly identified is3.02km~2,the correct recognition accuracy is 89.73%,the mass percentage is 81.43%,and the overall recognition effect is preferable.The landslide identification rule set was applied to the entire Chenghai-Binchuan fault zone,and a total of 284 landslides were identified in the area,with a total area of 12.01km~2.Except for omission and wrong identification,the correct identification area of landslides was 9.94km~2.The recognition accuracy is 82.76%,and the mass percentage is 72.08%.(3)The landslides in the Chenghai-Binchuan fault zone are mostly concentrated in the distance of 0-6km from the fault zone,the slope is 25-40°,the elevation is1500m-2000m,and the distance from the river system is 0-1km.Most of the landslides in the Dongpan are giant and super-large landslides distributed in the footwall of the fault zone,with obvious"footwall effect".At the same time,landslides are mostly distributed in the strata lithology of J_1-2,J₃,T₃bt,P₃ and CP,mainly rock landslides,and soil landslides are less developed.In addition,landslides are mainly distributed on west-facing slopes,and giant,extra-large,and large-scale landslides are also mostly distributed on slopes with southwest,west,and northwest slopes.(4)Earthquakes induced by the ancient and highly active Chenghai-Binchuan fault zone are the main inducing factors for the development of landslides in this area,and acting synergistically with various breeding factors such as stratigraphic lithology,precipitation,and human activities in the development of landslides in this area.Among them,the Longtan landslide and the Xiayuan landslide are more typical.The Longtan landslide developed in the upper part of the high and steep mountains or near the ridges.It was fractured by strong earthquakes,resulting in a movement form of shattering-bedding creep-front accumulation.It has the characteristics of long-distance sliding in the horizontal direction,and its volume is about 5.9×10~8m~3,the landslide has obvious characteristics,and the shape of"encircling chair-shaped negative terrain"is prominent.It belongs to a giant deep ancient earthquake landslide.The Xiayuan landslide has prominent"negative topography"features,with clear boundaries on both sides.The landslide is dominated by P₁ and C_2-3 disintegrated limestones.The main sliding direction of the landslide is NW286°.It is 3.9×10~8m~3 and belongs to a giant sliced ancient landslide.