Abstract:

The aim of the study is to conduct landslide susceptibility analysis for Şepker Stream Lower Basin. Şepker Stream flows in western Adıyaman from north to the south into Göksu Stream. In Şepker Stream Upper Basin lithology is composed of limestone, whereas the lower basin is composed of volcanic and clastic rocks. Due to the lithological structure of the lower basin extensive landslides have developed along the Şepker Stream Valley. Tepecik, Damdırmaz and Şerefli regions are the areas where most of the landslides were observed. Damdırmaz and Şerefli settlements were built directly on landslides. Especially during spring, after snowmelt and heavy rainfalls, landslides that affect the settlement, roads and agricultural areas are observed. With rainfall, the seasonal lake located in northern Tepecik, lithological structure and high slope values in valley shoulders trigger the formation of landslides. To determine the landslide susceptibility in Şepker Stream Lower Basin, weighted overlay method utilized in Geographical Information Systems (GIS) and Remote Sensing (RS) studies was used. In this method parameters such as lithology, the distance to fault lines, distance to streams and closure of vegetation are used. Field observations were conducted to verify the analysis results. Landslide inventory map was plotted based on the field studies and the susceptibility map was produced by overlaying parametric maps with the landslide inventory map. Based on the resulting map, 39% of the areas in Şepker Stream lower basin were low susceptibility; 23% were moderate susceptibility; and 38% were high and very high susceptibility areas. Based on these values, landslide risk should be considered as the primary risk in planning studies that would be conducted in Şepker Stream Lower Basin.