GIS-based landslide susceptibility mapping for a part of the North Anatolian Fault Zone between Reşadiye and Koyulhisar (Turkey)

Abstract

In the present study, landslide susceptibility assessment for a part of the North Anatolian Fault Zone between Reşadiye and Koyulhisar townships has been determined using index of entropy (IOE) and frequency ratio (FR) models within geographical information system. The landslide inventory map has been created in the study area. Altogether 91 landslides were mapped and 63 (69%) were randomly selected for modelling, with the remainder (28, 31%) used for validating the models. The landslide-conditioning factors, including slope degree, aspect, elevation, distance to faults, distance to streams, distance to road were selected. Subsequently, landslide susceptibility maps were produced using frequency ratio and index of entropy models. For verification, the receiver operating characteristic (ROC) curves were drawn and the areas under the curve (AUC) were calculated. The verification results showed that FR model (AUC = 75.71%) provided slightly better predictions than the IOE (AUC = 75.43%) model. According to the FR, about 32.54% of the study area is located within high to very high susceptibility classes of landslides. The interpretation of the susceptibility map indicates that distance to streams, distance to road and distance to fault play major roles in landslide occurrence and distribution in the study area. The landslide susceptibility maps like the one produced in this study should provide a valuable tool for the use of planners and engineers for reorganizing or planning new road and domestic constructions.