Landslides triggered by 5.12 Wenchuan Earthquake in the Mianyuan River Basin, China
Due to the high magnitude, long duration of vibration, and complicated environment of the disastrous area, 5.12 WenChuan earthquake triggered a large number of landslides. A spatial database, which included 1073 landslides, was developed and analyzed using post-earthquake ALOS satellite imagery, aerial photos and geographical information system (GIS) technology within one of the serious earthquake areas, the Basin of Mianyuan River. These landslides cover the area of 48.5km2, of which shallow, disrupted landslides occupy the widest area and the largest number. Near the co-seismic faults, the strong seismic wave caused the occurrence of many deep, high-speed and long-distance landslides as well as the formation of numerous barrier lakes. The second largest landslide triggered by the earthquake, Wenjiagou Landslide is located within this area and it has the farthest sliding distance. It is indicated in the GIS statistic analysis that the spatial distribution of earthquake-triggering landslides is dominated by the co-seismic fault. Owing to the duel effect of Yingxiu-Beichuan Fault and JiangyouGuanxian Fault, the landslides are mainly distributed in the hanging wall of two faults; the lithology of stratum determines the type of earthquake-triggering landslides. Shallow, disrupted landslides are mainly formed in the hard rocks such as magmatic rocks and dolomites, while deep landslides are likely to occur in the strata with hard upper structure and soft lower structure. Most landslides occur within the elevation range from 1000 to 2000 m above sea level. Gradient is one of the main controlling factor of landslides, for most landslides occur in the gradient range from 25 to 55 degrees; slope direction also affects the distribution of landslides. The slopes opposing the direction of seismic source (co-seismic fault) are more likely to have landslides than the slopes facing the direction seismic source (co-seismic fault).
W.L.Li R.Q.Huang C.Tang
State Key Laboratory of Geohazards Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan,China
国际会议
International Symposium and The 7th Asian Regional Conference of IAEG(国际工程地质与环境协会年会暨第七届亚洲工程地质会议)
成都
英文
949-960
2009-09-09（万方平台首次上网日期，不代表论文的发表时间）