Efficiency evaluation of different landslide susceptibility mapping methods

ABSTRACT: Distinguishing the susceptible areas to landslide using different models of landslide susceptibility mapping is one of the primitive and basic works to reduce probable damages and reduce risk. The main purpose of this study is the efficiency evaluation of four methods including Information value, Valuing area accumulation, Analytical Hierarchy Process (AHP), Kopta-Joshi proposed method for landslide susceptibility mapping in Zangvan watershed, Ilam province. At first, all the effective factors in landslide occurrence were inspected and by analyzing the parameters, nine factors including slope gradient, aspect, elevation, precipitation, distance from road, distance from fault, distance from drainage, land use and lithology were distinguished as the effective factors in landslides occurrence in the studied area. After preparing the information of these nine factors in GIS environment, every layer has been crossed with the landslide layer to find the role of corresponding layer in the formation of landslide. Then susceptibility mapping was performed with four methods. Finally, in order to evaluate the ability and verification of the susceptibility mapping, the occurred landslide dispersion map was crossed with susceptibility map. Results showed that 88 percent of occurred landslides locate in high and very high danger classes in information value method. Therefore, this method is more efficient in landslide susceptibility mapping in the Zangvan watershed than the other methods.

landslide susceptibility, mapping, Zangvan watershed