Study On Geological Disasters Induced By Mianning Section Of Anning River Fault Zone Based On Remote Sensing Technology

The Anning River fault zone is one of the three famous active faults in Southwest China,located in the Sichuan Yunnan diamond fault block.Its strong tectonic movement leads to the earthquake prone zone,and it is also a high incidence area of geological disasters.Active fault zone is the earth's internal energy release zone,the area where it was often present in complex geological environment,lithology,rock loose and fragile low strength,poor stability and other characteristics,these characteristics are likely to induce landslides,collapses,landslides and other disasters.On the basis of remote sensing interpretation technology,using high resolution 1 satellite images and interactive interpretation,the interpretation of geological structure and geological hazards of the Mianning section of the Anning River fault zone(1:5 10000)is carried out.The geological environment factors of the geological hazard and its development in the Mianning section of the Anning River fault zone are obtained,and the type,scale and spatial distribution characteristics of the geological disasters are determined.Combined with field investigation,the development characteristics of fault zone,formation condition and stability of geological disaster and geological disaster effect caused by fault zone are analyzed.The results and main conclusions are as follows.1)after remote sensing interpretation and field validation,64 landslides and 4 hidden trouble spots in the study area have been confirmed.There are 67 debris flow gullies and there are only landslides in the study area.In the space position,it shows the features of zonal distribution along the Mianning section of the Anning River fault zone.2)the geological hazard caused by the Mianning section of the Anning River fault zone is obvious.The turning point of the fault zone and main faults and secondary faults of the intersection,affected by tectonic stress,the number of geological disasters in the region more often,a larger scale,is the disaster and development of high density and high risk area.The hazard point on the hanging wall of the fault occupies 69.6%of the total point of disaster,and the footwall effect is obvious.In the range of 1km from the fault zone of Anning River,there are 80 disaster spots,accounting for 59%of the total,and the distance effect is obvious.3)the debris flow gully in the study area is rich in the source of material.Because when the fault zone through the river basin slope,rock and soil due to the long-term influence of fracture creep action,resulting in a higher degree of fragmentation,poor stability,low shear strength,the formation of unstable slopes,or even collapse.4)topography,meteorology,hydrology,formation lithology,slope gradient,and human engineering activities all affect the development of geological disasters in the study area.In mountain landscape provides a very favorable environment and potential advantages for airport disaster generation;strong weathered granite reduces the slope stability;landslide occurred in the slope of 26 degrees to 35 degrees,the altitude is above2000m,slope elevation difference in 50m?200m range of debris flow gully slope on both sides;on land,under the effect of rainfall,because of its poor stability,easy to change into its source.5)through field verification work,the stability of each landslide and hidden danger points,and the susceptibility of each debris flow ditch are determined by scoring method.And on this basis,combined with the actual threat of disaster points,the study area is divided into dangerous grades.It is found that the high risk areas are distributed on both sides of the Anning River fault zone,but mainly in the middle and high mountains on the East side.Through remote sensing interpretation and combining with the investigation of detailed field based on statistics carried out in-depth analysis and study,found that the induced effect of the Anninghe fault section of Mianning to the surrounding geological disaster is very obvious.And the risk classification of the study area,and then for the region's disaster prevention and mitigation project put forward targeted suggestions.