Abstract:

In order to investigate the spatial pattern of landslides along the major fault in Longmenshan area, the PALSAR interferometric pair with short baseline was utilized in the study. The atmospheric phase correction model with three dimensional geo-spatial factors was proposed to eliminate the long wavelength components. The LOS deformation threshold was set to reduce the short wavelength phase error. The terrain slope factor was introduced to analyze the spatial pattern of post-earthquake landslides triggered by the rainstorm. The results show that the active landslides presented clearly a linearly distribution along both sides of Yingxiu-Beichuan fault. The majority of landslides were about (3~15) km away from the major fault. The statistics data suggested that almost 90 percent of the post-earthquake landslides located in the elevation range of (1000~3000) m and the terrain slope factor (15~35) degrees. The spatial distribution characteristics with 70% landslides scattered on the hanging wall indicated that the after effect of hanging wall upthrusting motion dominated the pattern of post-earthquake landslides.

Key words: Post-earthquake landslides, Major fault, Short baseline InSAR, Spatial pattern, Hanging wall upthrusting effect