Production of landslide susceptibility maps by using AHP method and GIS analyses

Within the scope of this study, a landslide susceptibility analysis was carried out in the Inebolu Basin in the boundaries of the Kastamonu province in the Western Black Sea Region, where landslides occur frequently. In order to carry out the landslide susceptibility evaluation of this basin that has an area of 11400 hectares, the factors that may cause landslides were specified by considering the information obtained from the results of the literature reviews and the data related to the region. A total of 10 factors have been identified as: slope, aspect, elevation, curvature, distance to stream, topographic wetness index (TWI), sediment transport capacity index (LS), relative stream power (RSP), lithology, land cover/ use, and factor maps were generated by using Geographic Information System (GIS) based softwares. In the next stage, in order to identify the interrelation of each factors, classical Analytical Hierarchy Process (AHP) method, which has been often used in such analyzes in recent years, was considered and the landslide susceptibility map of the region was produced by obtained. Besides, 4 different results were obtained from 4 different experts who had worked in the field and had been in the region many times for field works. As a result, 4 more different result maps were generated and also an average landslide susceptibility map, that is the average of both the author's and 4 experts' results, was also produced. In addition, the performances of all maps were checked by ROC analysis and satisfactory performance results were obtained. Finally, in accordance with the opinions of the author and 4 experts, it was determined that the most effective parameters related to landslides in the region are slope, elevation, lithology, distance to stream and land use/cover. Keywords: Geographic Information System (GIS), Analytic Hierarchy Process (AHP), landslide, landslide susceptibility, Inebolu Basin