## 3 Results  
In Figure 3, the violin plots of the AUC values obtained by the replicates for each model group (related to the mapping unit size) are reported. For each group, the variability of the models' AUC values is represented by the length of each violin, while the width reflects the number of replicates showing the specific value.  
The comparison of the performances of the models for the three landslide typologies, obtained for the varying cell size suite, confirmed the expected influence of the mapping units' size on the accuracy of the models. The AUC values for slide and slope flows were marked by a maximum value for the 8 m cell size and a minimum for 32 m, with differences  
Figure 3: AUC values of replicates of each modelling procedure with respect to the three different landslide typologies, both in prediction and in success validation.  
of about 0.03. The 8 m models approached outstanding--for slide--and excellent--for slope flows--AUC levels. In general, the results regarding local flows showed poorer performances, but a linear positive trend was clearly shown in the AUC values with increasing cell size, up to a largely satisfactory response for 32 m. In addition, generally, the local-flow models were characterised by a less pronounced dispersion through the replicates for the same size.  
The validation indices obtained by assuming the Youden index score cut-off (Figure 4) reflected a smoother version of what was observed from the ROC plots, with the 8 m size confirming the best trade-off between sensitivity and specificity, and an almost undifferentiated scenario for the derived accuracy estimation.  
The analysis of the variable importance for the three model suites (Figure 5) allowed us to verify both the adequacy of the models and the effect caused by the cell size changes. Elevation and slope steepness play a strong controlling role in general slope instability conditions and were selected as ubiquitin factors. Slope landslides (slides and slope flows) were shown to be more sensitive to slope geometry, with both the profile and plan curvature being selected as important factors, while local flows only showed a weak link to plan curvature. Lithoid units' class was the only outcropping lithology selected for slides, whilst clays and marly clays were also selected for slope flows. At the same time, local flows selected a large fan of outcropping lithologies, also including pelites, old landslide deposits and the Numidian Flysch sandstone, the latter probably due to the weathered mantle. The topographic wetness index had a significant role in terms of slides and slope flows, which  
Figure 4: Barplots of the main validation indices of the confusion matrix (sensitivity, specificity and accuracy) of each modelling procedure with respect to the three different landslide typologies, both in prediction and in success validation.  
could be ascribed to the role of potential water saturation in the failure mechanism. A very weak link was shown between slides and land cover. Arable land areas are prone both to slope flows and local flows; the latter are also controlled by forest land cover.  
Figure 5: Comparison of the variable importance of the models for (**a**) slide type, (**b**) slope flow and (**c**) local flow. The thicker lines identify the variables which are employed for the 30% of replicates.