Landslide susceptibility mapping using analytical hierarchy process and GIS in Balarud region, northern Khouzestan Province

Landslide phenomenon is one of the most destructive disasters in hilly regions which are responsible for significant socialeconomic damages. Due to lithological and geomorphological features as well as active tectonics, Balarud region is prone to landslide disaster so that 55 landslides record in the area. This study presents an assessment of landslide susceptibility map using the combination of maps in a GIS environment, regarding the cognizance of local experts. Initially, seven layers of landsliderelated factors were prepared, including altitude, slope angle, aspect, proximity to drainage network, lithology, land use, proximity to faults and lineaments, as well as proximity to the road network. Then, analytic hierarchy process (AHP) was applied so as to determine the relative weights of each landslide instability factor using Expert Choice 11 software. The resulting susceptibility map was classified into five classes, namely, very high, high, moderate, low, and very low. It demonstrates that about 32.3% and 35.6% of the study area belong to the very high and high susceptibility classes, respectively. Performance of the proposed model was evaluated using 20% of all mapped landslides considered for testing the model. The outcome was that 72.73% and 27.27% of the tested landslides completely fit into the very high and high susceptibility classes, respectively. The results revealed that the AHP model produced reasonable accuracy.