| In recent years,earthquake landslide disasters have aroused widespread concern.They have a wide range of disasters and a large range,destroying lifeline projects such as power transmission equipment and power stations.Ludian County is located in the northeastern part of Yunnan Province.The terrain is high on both sides of the east and the west,and the middle is low and flat.Plateaus,hills,and basins are intricately distributed.It is a prone area for landslide disasters.To this end,this paper established a Ludian County earthquake landslide risk prediction model based on potential earthquakes,conducted detailed research and risk prediction of future earthquake landslides in Ludian County,and compiled a seismic landslide risk zoning map for Ludian County.The county's future urban development,road planning,reservoir site selection,important pipeline layout,land use of engineering projects,and disaster prevention and mitigation work provide important references.Future earthquakes are random in time and space,and their intensity and frequency cannot be determined.For areas prone to earthquake landslides,when carrying out risk assessment and zoning,it is necessary to consider the impact of all surrounding potential sources on the study area.Based on the Newmark cumulative displacement method,this paper uses the full probability model to fully consider the impact of the potential source area on the risk of landslides and proposes a potential earthquake-based seismic landslide risk evaluation model.(1)Collected and arrange 6 strong motion observation records that occurred in the Sichuan-Yunnan area,and screened out records with peak acceleration PGA greater than0.2g,a total of 58 data.Analyze the existing empirical relationship of permanent displacement,and use Origin software to fit an empirical formula suitable for permanent displacement in Sichuan-Yunnan area.(2)The landslide susceptibility part uses the Arc GIS platform software raster calculator module.The natural slope raster data derived from the 1:100000 digital elevation model and the 1:200000 geological and rock-soil shear strength parameter raster data are superimposed to calculate the critical acceleration value.(3)A model of seismic landslide risk assessment based on potential seismic sources is deduced,and the corresponding algorithm is compiled using Python sentences.The derived annual probability curve function of transcendence.Using the full probability calculation model,the probability zoning map of the earthquake and landslide in Ludian County in the next 50 years is finally obtained,and the hazard is classified according to the probability value.The results show that in Ludian County,the safe area accounts for 36.79%,the extremely low risk area accounts for 45.05%,the low risk area accounts for 5.44%,the moderate risk area accounts for 1.55%,and the high risk area accounts for 11.17%.Within the territory of Ludian County,the central,northern and southeastern regions are in safe or extremely low-risk areas,with a total area of 1216.96 km~2,which is suitable for promoting the process of urbanization.The probability of occurrence of earthquake landslides along the Niulan River in the southwest is relatively high,with a total area of189.15 km2 in the medium and high danger zone.The follow-up work should be comprehensively considered and moderately avoided high-risk areas. |
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