An improved method of Newmark analysis for mapping hazards of coseismic landslides

Abstract. Coseismic landslides have been responsible for destroyed buildings and structures, dislocated roads and bridges, cut off of pipelines and lifelines, and tens of thousands of deaths. Newmark's method is widely applied to assess the permanent displacement along a potential slide surface to determine the coseismic responses of the slope. The M_w 6.1 (USGS) earthquake in Ludian, Yunnan Province, China in 2014 has caused widespread landslides and provided the ideal data sets to conduct a regional analysis of coseismic stability of slopes. The data sets include the topography, shear strength, and ground shaking of the study area. All of these data sets are digitized and rasterized at 30 m grid spacing using ArcGIS and combined in a dynamic slope model based on Newmark permanent-deformation analysis. The application of Barton model was then applied in the permanent-deformation analysis. According to a method of inexact reasoning, comparisons are made between the predicted displacements and a comprehensive inventory of landslides triggered by the Ludian earthquake to map the spatial variability in certainty factors. A coseismic landslide hazard map is then produced based on the spatial distribution of the values of certainty factors. Such map can be applied to predict the hazard zone of the region and provide guidelines for making decisions regarding infrastructure development and post-earthquake reconstruction.