GIS-Based Landslide Susceptibility Mapping by AHP Method, A Case Study, Dena City, Iran

Slope instability research and susceptibility mapping is a fundamental component of hazard management in decreasing the risk of living with landslides. Landslide susceptibility is defined as the proneness of the terrain to produce slope failures and susceptibility is usually expressed in a cartographic way. The Dena city in Iran is a landslide prone zone because of its own characteristics including the mountainous topography, climate conditions, seismic potential, geology and geomorphology. Landslides have been resulting in damage to roads and villages of this region therefore landslide susceptibility map for this area can save lives and prevent sever damages. In this study, the analytical hierarchy process (AHP) is employed to produce susceptibility maps. For this purpose, eight layers including landslide inventory, raining, lithology-weathering, earthquake, slope, land cover, distance to stream, and distance to road will be considered. Using this method each layer is broken into smaller factors, then these factors are weighted based on their importance, and finally the last prepared layers are assembled and the final map is generated. Commercial software ArcGis is used to produce the layer maps which are used in the production of the landslide susceptibility maps. Based on the scale of the available topographic maps used in this research, the scale of final susceptibility maps is chosen to be 1:50000.