## 3 Results
### Susceptibility Map and Validation  
The summation of the C of all causal factors (slope, aspect, extreme precipitation, NDVI, lithology, CLC, TWI), representing layers in a GIS environment, allowed the definition of a landslide susceptibility map. The values found were then rescaled to a value between 0 and 100, where 100 indicates the maximum landslide probability in that area and 0 indicates the minimum landslide probability in that area (Figure 6). Figure 5: Maps of causal factors: (**a**) slope; (**b**) aspect; (**c**) extreme precipitation 1991–2020; (**d**) NDVI; (**e**) lithology; (**f**) CORINE land cover; (**g**) TWI. The class with the largest area is the 70-80 class, with a total area of 2896.69 km\({}^{2}\), while the class with the smallest area is the 0-10 class, with a total area of 0.03 km\({}^{2}\); the largest LSI, indicated by the 90-100 class, has an area of 393.94 km\({}^{2}\), which corresponds to 4.21% of the entire study area (Table 2). \begin{table}
\begin{tabular}{c c c c c} \hline
**Causal Factor** & **Classes** & \(W^{+}\) & \(W^{-}\) & \(C\) \\ \hline \multirow{8}{*}{SLOPE} & 0–16\({}^{\circ}\) & \(-\)0.18 & 0.13 & \(-\)0.31 \\  & 16–25\({}^{\circ}\) & 0.35 & \(-\)0.29 & 0.64 \\  & 25–35\({}^{\circ}\) & \(-\)1.18 & 0.03 & \(-\)1.22 \\  & \(>\)35\({}^{\circ}\) & \(-\)0.61 & 0.06 & \(-\)0.66 \\ \hline \multirow{8}{*}{ASPECT} & FLAT (0\({}^{\circ}\)) & \(-\)2.40 & 0.04 & \(-\)2.44 \\  & NORTH (337.5–22.5\({}^{\circ}\)) & 0.50 & \(-\)0.03 & 0.53 \\  & NORTH-EAST (22.5-67.5\({}^{\circ}\)) & 0.23 & \(-\)0.04 & 0.27 \\  & EAST (67.5–112.5\({}^{\circ}\)) & 0.03 & \(-\)0.01 & 0.04 \\  & SOUTH-EAST (112.5–157.5\({}^{\circ}\)) & \(-\)0.34 & 0.05 & \(-\)0.39 \\  & SOUTH (157.5–202.5\({}^{\circ}\)) & \(-\)0.46 & 0.04 & \(-\)0.51 \\  & SOUTH-WEST (202.5–47.5\({}^{\circ}\)) & \(-\)0.29 & 0.03 & \(-\)0.32 \\  & WEST (247.5–292.5\({}^{\circ}\)) & \(-\)0.01 & 0.00 & \(-\)0.01 \\  & NORTH-WEST (292.5–337.5\({}^{\circ}\)) & 0.31 & \(-\)0.05 & 0.36 \\ \hline \multirow{8}{*}{EXTREME DAILY} & 100–115 & 0.23 & \(-\)0.05 & 0.28 \\  & 115–130 & \(-\)0.02 & 0.01 & \(-\)0.02 \\  & 130–145 & 0.17 & \(-\)0.04 & 0.21 \\  & 145–160 & 0.13 & \(-\)0.02 & 0.15 \\  & 160–175 & \(-\)0.12 & 0.01 & \(-\)0.14 \\  & 175–190 & \(-\)0.46 & 0.02 & \(-\)0.48 \\  & 190–205 & \(-\)0.78 & 0.03 & \(-\)0.81 \\  & 205–250 & \(-\)1.59 & 0.03 & \(-\)1.61 \\ \hline \multirow{8}{*}{NDVI} & \(-\)1 to 0.2 & 0.61 & \(-\)0.00 & 0.61 \\  & 0.2 to 0.5 & 0.05 & \(-\)0.02 & 0.07 \\  & 0.5 to 1 & \(-\)0.03 & 0.06 & \(-\)0.09 \\ \hline \multirow{8}{*}{LITHOLOGY} & Clays and marly clays with intercalations of sandstone, sands and conglomerates & \(-\)0.08 & 0.01 & \(-\)0.09 \\  & Deposits & 0.34 & \(-\)0.39 & 0.73 \\  & Limestones, flinty limestones, subordinately marls and clay marls & \(-\)1.20 & 0.11 & \(-\)1.32 \\  & Marls, clay marls and marly limestones & \(-\)0.31 & 0.02 & \(-\)0.33 \\  & Sandstones, marly clays, subordinately conglomerates & \(-\)0.48 & 0.06 & \(-\)0.54 \\  & Shales and marls encompassing calcareous, marly limestones and arenaceous bodies & \(-\)1.54 & 0.01 & \(-\)1.55 \\ \hline \multirow{8}{*}{CLC} & Artificial surface & \(-\)1.32 & 0.04 & \(-\)1.36 \\  & Agricultural surface used & 0.21 & \(-\)0.49 & 0.69 \\  & Semi-natural wooded territories & \(-\)0.40 & 0.15 & \(-\)0.54 \\  & Water bodies & \(-\)1.41 & 0.00 & \(-\)1.41 \\ \hline \multirow{8}{*}{TWI} & 0–2 & \(-\)3.46 & 0.00 & \(-\)3.46 \\  & 2–4 & \(-\)0.58 & 0.03 & \(-\)0.60 \\  & 4–6 & 0.11 & \(-\)0.11 & 0.23 \\  & 6–8 & 0.07 & \(-\)0.04 & 0.11 \\  & 8–10 & \(-\)0.01 & \(-\)0.01 & \(-\)0.01 \\  & 10–12 & \(-\)0.49 & 0.01 & \(-\)0.50 \\  & 12–23 & \(-\)1.14 & 0.02 & \(-\)1.16 \\ \hline \end{tabular}
\end{table} 
Table 1: Causal factors with division into classes and the relative positive (\(W^{+}\)) and negative (\(W^{-}\)) weight of each class, summarized in the contrast value (\(C\)). Therefore, according with the scientific literature, the landslides susceptibility map are divided into five classes: very low, low, moderate, high and very high [51].