Statistical Analysis of the Key Factors of Landslide Induced by Wenchuan Earthquake

Abstract

The distribution of landslides triggered by Wenchuan Earthquake is controlled by a variety of geological factors. Statistical results of 2,445 landslides of the four river basins show that all these factors, including the causative faults, slide direction, landform and the own properties of the slope have its contribution to the landslides distribution. In order to find out which factors have more significant influence on the landslide distribution, it is necessary to put all factors into consideration. Multivariate statistical analysis of these landslides shows that, in the near field of the causative fault during high intensity earthquake, landslides were affected distinctly by the strength of the seismic wave, instead of the properties of the slope itself such as slope structures and lithology. The factors can be generalized into five parts, which represent 76.15 % of the data set. In these factors, the first three are directly connected to the strength of the seismic wave, and the last two components involving the nature of the slope itself. Both the field investigation and statistic reveal that in the strong shock mountainous areas, the structure of the slope is not so important as usual.