A Comparative Study of the Frequency Ratio, Analytical Hierarchy Process, Artificial Neural Networks and Fuzzy Logic Methods for Landslide Susceptibility Mapping: Taskent (Konya), Turkey

In this study, the four landslide susceptibility (LS) mapping methods, frequency ratio (FR), analytic hierarchy process (AHP), artificial neural networks (ANN) and fuzzy logic (FL) method, are compared. The study has been conducted in Taskent (Konya, Turkey) Basin which is located between 36.88 N to 36.95 N latitudes and 32.35 E to 32.53 E longitudes. The survey area is approximately 80 km(2). The FR, AHP, ANN and FL methods are used to map LS. Thematic layers of fourteen landslide conditioning factors including landslide inventory, elevation, slope, slope aspect, plan, and profile curvature, sediment loading factor, stream power, and wetness index, drainage, and fault density, distance to drainage, and fault, geological units, and land use-land cover are used for preparing the LS maps. Estimation power of models has been evaluated by the relative operating characteristic curve method. The areas under the curve for FR, AHP, ANN and FL method have been computed as 0.926, 0.899, 0.916 and 0.842, respectively. These results showed that FR method is relatively good, whereas FL method is a relatively poor estimator for susceptibility. The validity of the LS maps was evaluated by test landslides. The 58 test landslides (76 pixels), 43 training landslides (200 pixels), and 101 total landslides (276 pixels) have been put onto the LS maps prepared by the various methods. The percentages of the existing landslide pixels within the different landslide occurrence potential classes were determined. It is determined that a significant portion of all landslides (76% in the ANN, 83% in the FR, 87% in the AHP and 89% in the FL method) belong to the high and very high LS class. The produced four susceptibility maps were also compared using cross-correlation methods. The cross-correlation coefficients were found to be 0.82, 0.70, 0.63, 0.54, 0.48, and 0.45 for AHP versus FR, FR versus FL, AHP versus FL, AHP versus ANN, FR versus ANN, and FL versus ANN maps, respectively. Here, the confidence level is 0.95. The FR and AHP methods have been assessed to be more suitable methods among other used methods.