Abstract. Coseismic landslides can destroy buildings, dislocate
roads, sever pipelines, and cause heavy casualties. It is thus important but
challenging to accurately map the hazards posed by coseismic landslides.
Newmark's method is widely applied to assess the permanent displacement
along a potential slide surface and model the coseismic response of slopes.
This paper proposes an improved Newmark analysis for mapping the hazards of
coseismic landslides by considering the roughness and effect of the size of the
potential slide surfaces. This method is verified by data from a case study
on the 2014 Mw 6.1 (the United States Geological Survey) Ludian
earthquake in Yunnan Province, China. Permanent displacements due to the
earthquake ranged from 0 to 122 cm. The predicted displacements were
compared with a comprehensive inventory of landslides triggered by the
Ludian earthquake to map the spatial variation in the hazards of coseismic
landslides using the certainty factor model. The confidence levels of
coseismic landslides indicated by the certainty factors ranged from −1 to
0.95. A hazard map of the coseismic landslide was generated based on the
spatial distribution of values of the certainty factor. A regression curve
relating the predicted displacement and the certainty factor was drawn, and
can be applied to predict the hazards of coseismic landslides for any
seismic scenario of interest. The area under the curve was used to compare
the improved and the conventional Newmark analyses, and revealed the
improved performance of the former. This mapping procedure can be used to
predict the hazards posed by coseismic landslides, and provide guidelines
for decisions regarding the development of infrastructure and
post-earthquake reconstruction.
Factors controlling the spatial distribution of coseismic landslides triggered by the Mw 6.1 Ludian earthquake in China
