Large scale landslide susceptibility assessment using the statistical methods of logistic regression and BSA – study case: the sub-basin of the small Niraj (Transylvania Depression, Romania)
S. Roşca1, Ş. Bilaşco1,2, D. Petrea1, I. Fodorean1, I. Vescan1, S. Filip1, and F.–L. Măguţ11"Babeş-Bolyai" University, Faculty of Geography, 400006 Cluj-Napoca, Romania 2Romanian Academy, Cluj-Napoca Subsidiary Geography Section, 9, Republicii Street, 400015 Cluj-Napoca, Romania
Received: 07 Nov 2015 – Accepted for review: 14 Nov 2015 – Discussion started: 27 Nov 2015
Abstract. The existence of a large number of GIS models for the identification of landslide occurrence probability makes difficult the selection of a specific one. The present study focuses on the application of two quantitative models: the logistic and the BSA models. The comparative analysis of the results aims at identifying the most suitable model. The territory corresponding to the Niraj Mic Basin (87 km2) is an area characterised by a wide variety of the landforms with their morphometric, morphographical and geological characteristics as well as by a high complexity of the land use types where active landslides exist. This is the reason why it represents the test area for applying the two models and for the comparison of the results. The large complexity of input variables is illustrated by 16 factors which were represented as 72 dummy variables, analysed on the basis of their importance within the model structures. The testing of the statistical significance corresponding to each variable reduced the number of dummy variables to 12 which were considered significant for the test area within the logistic model, whereas for the BSA model all the variables were employed. The predictability degree of the models was tested through the identification of the area under the ROC curve which indicated a good accuracy (AUROC = 0.86 for the testing area) and predictability of the logistic model (AUROC = 0.63 for the validation area).
Roşca, S., Bilaşco, Ş., Petrea, D., Fodorean, I., Vescan, I., Filip, S., and Măguţ, F. –L.: Large scale landslide susceptibility assessment using the statistical methods of logistic regression and BSA – study case: the sub-basin of the small Niraj (Transylvania Depression, Romania), Nat. Hazards Earth Syst. Sci. Discuss., 3, 7171-7201, doi:10.5194/nhessd-3-7171-2015, 2015.