LANDSLIDE RISK ASSESMENT USING SINMAP (BARTIN-SÖKÜ SAMPLE STUDY)

Abstract

SINMAP (Stability Index Mapping) software is an ArcView extension developed by Environmental Systems Research Institute (ESRI) that is used to evaluate landslide risk at basin scale. SINMAP classification utilizes stability index values calculated at basin scale. The theoretical basis of SINMAP is an infinite slope stability model. A digital elevation model (DEM) is used to identify variables such as slope, soil moisture, and flow directions; and also takes into account factors such as permeability, water retention capacity, friction and root structure that might affect slope status. However, various difficulties might be encountered in calculating certain variables, which are therefore characterized by standard distribution within certain limits based on soil, vegetation and geological data. The software allows interactive calibration of variables according to observed landslide distribution. Using the variables reduces the possibility of assigning a low stability index in areas where no landslides are observed, whereas the possibility of observing landslides in areas with low stability index can be increased. In this study, a model developed by Pack et al. (2001) is explained according to infinite slope stability model and topographic wetness index. These two components are used to define SI in Sökü Department of Forestry.SINMAP (Stability Index Mapping) software is an ArcView extension developed by Environmental Systems Research Institute (ESRI) that is used to evaluate landslide risk at basin scale. SINMAP classification utilizes stability index values calculated at basin scale. The theoretical basis of SINMAP is an infinite slope stability model. A digital elevation model (DEM) is used to identify variables such as slope, soil moisture, and flow directions; and also takes into account factors such as permeability, water retention capacity, friction and root structure that might affect slope status. However, various difficulties might be encountered in calculating certain variables, which are therefore characterized by standard distribution within certain limits based on soil, vegetation and geological data. The software allows interactive calibration of variables according to observed landslide distribution. Using the variables reduces the possibility of assigning a low stability index in areas where no landslides are observed, whereas the possibility of observing landslides in areas with low stability index can be increased. In this study, a model developed by Pack et al. (2001) is explained according to infinite slope stability model and topographic wetness index. These two components are used to define SI in Sökü Department of Forestry.