Brief Communication: Landslides triggered by the <i>M</i>_s =7.0 Lushan earthquake, China

Abstract

Abstract. Earthquake-triggered landslide has drawn much attention in the world because of severe hazards it causes. The Ms =7.0 Lushan earthquake which occurred on 20 April 2013, China, in the Longmen Shan mountain region triggered more than 1000 landslides and really blocked many roads and exacerbated the overall transportation problems in the mountainous region. Preliminary landslides inventory is complied based on the high-resolution remote sensing images. Based on it, landslides spatial distribution characteristics and correlations between the occurrence of landslides with geologic and geomorphologic conditions are analyzed. Statistic analysis is conducted by using landslide point density (LPD), which is defined as the number of landslides per square kilometer. It is found that LPD have strong positive correlations with slope gradients, and the landslides are likely to occur in younger strata systems like Quaternary and Tertiary sediments. Spatially, the triggered landslides are controlled by the causative faults in their distribution and mainly concentrate around the epicenter. All the landslides are located within the area with seismic intensity ≥ VII and in scale with the seismic intensity. LPD decreases with increasing distance from the epicenter, and sometimes landslides are found densely presented along the roads in the mountainous. It is found that the empirical distance–magnitude relation are more suitable for estimating the landslides concentrated area during the Lushan earthquake.