Landslide Susceptibility Mapping: A Comparison of Information and Weights-of-Evidence Methods in Three Gorges Area

Statistical assessment of landslide susceptibility has become a major topic of research in the last decade. In this study, the information and weights-of-evidence methods have been used with GIS to prepare a landslide susceptibility map in a selected area of the Shunxi segment of Zhongwu gas pipeline in Zhong County. For this purpose, causative factors including landslide inventory, engineering geological petrofabric, slope, slope structure, distance to river and distance to road were used. In this study area, all of landslides occurred in J₃p formation. Distance to roads, slope structure and distance to rivers were found to be important factors in the study area. To confirm the practicality of the results, the two susceptibility maps were compared with a landslide inventory map containing 5 landslides zones. The outcome was that the known landslide zones do not completely fit into the high and very high susceptibility classes. But 93.2% of these landslide zones fall into high and very high susceptibility zones of the information method while this is 92.2% fall into high susceptibility zones in the case of weights-of-evidence method, which is similarity. Finally, the ratio of landslide density of the susceptibility class and the landslide density of the study area was compared, which showed that the weights-of-evidence method reasonable picture of the actual distribution of landslide susceptibility, than the information method.