Generalised linear modelling of susceptibility to landsliding in the central Apennines, Italy

Generalised linear modelling was used to model the relation between landsliding and several independent variables (geology, dip, strike, strata-slope interaction, aspect, density of lineaments and slope angle) for a small area of the central Apennines, Italy. Raster maps of landsliding and the independent variables were produced from air photographs, topographic and geological maps, and field checking. A logistic regression was then obtained between all slope movements and the independent variables (chosen to reflect conditions prior.to landsliding). Not surprisingly, geology and slope angle were found to be the most significant factors in the model. The landslides in the region were then classified into dormant and active types and further linear models were obtained for each. While geology and slope angle were again the most significant factors in each model, slope aspect and strike were less significant for active landslides. Finally, further independent variables applicable to active landslides only (vegetation cover, soil thickness, horizontal curvature, vertical curvature, concavity of slope, local relief and roughness) were added to the model for active landslides. Interestingly, with these new variables added, vegetation cover and concavity of slope were found to be more significant than geology and slope angle. (C) 1998 Elsevier Science Ltd. All rights reserved.