Debris flow susceptibility and propagation assessment in West Koyulhisar, Turkey

Turkey is highly prone to landslides because of the geological and geographic location. The study area, which is located in a tectonically active region, has been significantly affected by mass movements. Flow type landslides are frequently observed due to this location. This study aims at determining the source area and propagation of debris flows in the study area. We used the heuristic method to extract source areas of debris flow, and then used receiver operating characteristic (ROC) curve analysis to assess the performance of the method, and finally calculated the Area under curve (AUC) values being 83.64% and 80.39% for the success rate and prediction rate, respectively. We calculated potential propagation area and runout distance with Flow-R software. In conclusion, the obtained results (susceptibility map, propagation and runout distance) are very important for decision-makers at the region located on an active fault zone, which is highly prone to natural disasters. The outputs of this study could be used in site selection studies, designing erosion prevention systems and protecting existing human-made structures.