Journal of Engineering Geology

This paper presents landslide assessment and landslide hazard zonation of the Polroud Dam area. Polroud Dam is one of the largest dams that are in construction, 29 km south of Roudsar in Gilan Province. Considering to geomorphology and geological conditions of the area, the site is susceptible to landslide hazard. Field survey shows many evidences of the instabilities especially in the slopes overlooking to the dam and the reservoir. The historical record also demonstrates high potential of the region to slope instabilities. A large landslide that occurred in 1996 discern that the frequency of the hazard in the region. Therefore, Identification of the landslide potential hazard is vital before impounding the reservoir. In this study, we investigated landslide hazard in the site and we have prepared landslide hazard zonation map using the main parameters. These parameters include; slope percent, slope aspect, lithology, fault, roads, drainage catchment, elevation, vegetation and precipitation amount. Analytic Hierarchical Process (AHP) has been used to prepare and to cross the maps. The results show that about 26 percent of the slopes are situated in highly hazard zones. It was determined also that lithology and slope aspects play main role in occurring of the landslides in the study area.