GIS-based landslide susceptibility assessment: a case study in Kelemen Valley (Yenice-Karabuk, NW Turkey)

WOS: 000384333000059This study focuses on revealing the landslide susceptibility of mainly the Kelemen Valley and adjacent valleys in the Western Black Sea Region of Turkey by investigating the parameters causing landslide occurrences in the region in a GIS environment and applying the frequency rate method on landslide-prone areas. Many buildings and houses in the study area, 382 houses to be exact, had to be evacuated by the General Directorate of Disaster Affairs of Turkey based on the findings from landslide studies conducted in the region since 1950 and were declared "unsuitable for construction and residence due to disaster." Therefore, it is of a vital significance to disclose the factors of landslide occurrences in the Kelemen Valley and consequently to prepare landslide susceptibility maps. For this purpose, 82 landslide exposed areas are determined by field surveys and checked against satellite imagery. All 82 landslides are found to have occurred in the Cretaceous Ulus Formation with the same climate and same vegetation, which are not considered distinctive parameters for the region. These findings have given rise to exclude these parameters from analyses on the basis that they are proclaimed as common parameters; instead, the parameters such as slope, aspect and distance to river are taken into consideration and assessed in ArcGIS software. Finally, the landslide susceptibility of the region has been obtained. Furthermore, a comparison is conducted between the existing landslides and the outcome map, and it is deduced that the map produced has a correlation ratio of 86 % with the existing occurrences for high-risk areas. This finding clearly dictates that land-slideprone areas need to be accounted for when planning for new settlement areas

A comparison of GIS-based landslide susceptibility assessment of the Satuk village (Yenice, NW Turkey) by frequency ratio and multi-criteria decision methods

Landslide is one of the most influential natural disasters that cause losses of life and property on a large scale. To identify the landslide susceptible areas, the layers of data showing different characteristics of the earth must be evaluated together. In the course of evaluating data layers together, the emerging technology of geographical information systems (GIS) allows the collection, processing and analysis of data. The purpose of this study is to produce a landslide susceptibility map of the Satuk village in the Yenice district of the province of Karabuk in the Western Black Sea Region where landslides causing frequent loss of life and property occur frequently. In the area, the slope, lithology, aspect, elevation, distance to river and distance to road parameters were considered as the parameters causing the landslides. All of the parameters were standardized in a common scale using fuzzy membership functions. Then, the contributions of each of these parameters for the landslide occurrence were investigated by frequency ratio, and GIS-based multi-criteria decision analysis, and the weight values of the parameters were calculated. The generated landslide susceptibility map is divided into five classes. Additionally, the landslide inventory map was compared to the obtained landslide susceptibility maps to find out how well the constructed models fit the reality. An overlap of 81.56% was found based on the multi-criteria decision analysis method and an overlap of 89.96% was found based on the frequency ratio method. The results showed that the frequency ratio method provides better results than the multi-criteria decision analysis method considering the data used for the study area