GÖKDERE HAVZASI VE ÇEVRES N N (B NGÖL GÜNEYBATISI) FREKANS ORANI METODUNA GÖRE HEYELAN DUYARLILIK ANAL Z The Landslide Susceptibility Analysis of the Gökdere Basin and its Surrounding Region (The Southwest of Bingöl) According to the Frequency Ratio Method

In this study, it is aimed to do the landslide susceptibility analyses of the Gokdere Basin and its surroundings as one of the tributaries of the Murat River located in the southwest of Bingol Basin. Landslides are seen intensely in Gokdere which is located in the southwest of Bingol and its surroundings due to the lithological, tectonic, morphological and climate features. The landslides which are seen in Bahceli, Suvaran, Gokdere and Bahceli villages affect the settlement, highway and farm lands. Substitutions and residential transfers are observed due to the frequent landslides in Gokdere and Yumakli settlements. The basin and its surrounding region consisting of the lithological agglomerate, tuff, basalt and marl are located in the East Anatolian Fault Zone (EAFZ) and earthquakes occur due to the movements of EAFZ. The slope values are high with the effect of tectonic lines and stream erosion. Vegetation is rather sparse in the study area where the snow depth reaches up to 3-4 metres in the winter. Landslides caused by the susceptible natural conditions lead to important economical losses. A landslide susceptibility map is made for Gokdere Basin and its surrounding region using the frequency ratio method, lithology, distance to the fault lines, slope, aspect distance to the streams and vegetation. Cell numbers of each layer and cell numbers with landslide in these layers have been determined by geographical information systems, and using these data landslide susceptibility index (LSI) has been created and assigned to the database of factor maps. A susceptibility map is made by compiling the factor maps. According to the created susceptibility map, all of the settlements, farm lands and highways are located in the medium and high risk area. Landslides are inevitable in the tectonically active area. Therefore, the planning should be made by taking the the landslide susceptibility map into consideration.