The Introduce of Indices to Predict Geology Unites Susceptibility to Coseismic Landslides; Manjil Earthquake as a Case study

The analysis of distribution and characteristics of landslides triggered by earthquakes is important to understand the areas may be susceptible to landsliding in the next earthquakes. One of the most significant effects of the Manjil earthquake (M=7/7, 20/6/1990) was triggering landslides over an extensive area. In this study; the factors of these landslides such as slope, slope aspect, elevation, lithological unites and Arias intensity were investigated using GIS in an area close to the earthquake epicenter. In the next step, two indices called Susceptibility Index (SI) and Frequency Index (FI) presented to predict the location of future earthquake-induced landslides. Finally, landslides susceptibility in the study area has been rated based on these indices. The output of thisstudy can be used to predict landslide susceptible areas in the future earthquakes and to distinguish hazard zones in the overall study area.