## 3 Results
### Combination Model  
With the aim to combine statistical, displacement and damage information to study the road stretches exposed to slow-moving landslide risk at the municipal scale, first the kinematic characteristics of the slow-moving landslides are investigated using the available DInSAR dataset. According to the scale of analysis and the resolution of the monitoring data, only the slow-moving landslides covered by at least three coherent benchmarks were selected [37]. These latter are assigned an average velocity value computed as the arithmetic mean of the yearly \(V_{LOS}\) of each benchmark falling within the considered landslide body. Figure 5a,b show the maps of covered slow-moving landslides with an indication of the velocity class obtained. In both study areas, some landslides (23.7% of the total covered in Vaglio Basilicata and 22.4% of the total covered in Trivigno) are moving (i.e., the average velocity value exceeds the threshold, fixed in this study equal to \(\pm\)1.5 mm/year) in the observation period.  
On the other hand, focusing on the road network under investigation and considering the coherent DInSAR benchmarks (Figure 5b,d) within the \(TZU\) (see Section 2.1.2), an average velocity value is computed as the arithmetic mean of the yearly \(V_{LOS}\) associated with each coherent benchmark falling within the \(k\)th \(TZU\). Then, according to the proposed procedure, the indicator of movement (i.e., \"moving\" or \"not moving\") is assigned to the \(TZU_{rond}\) based on the velocity value of the pertaining \(TZU\) (if covered) or deriving from the interacting slow-moving landslide (if any).  
Figure 4: Landslide susceptibility maps at the municipal scale defined employing focal statistics techniques with characteristic dimension equal to 7. Slow-moving landslides recorded in the two test areas are also reported. The inset shows the location of the two municipalities within the Basilicata region.  
Figure 5: Maps of the slow-moving landslides for Vaglio Basilicata (**a**) and Trivigno (**c**) distinguished according to the average DInSAR-derived velocity values with close-up view of yearly V\({}_{\text{LOS}}\) of analyzed coherent DInSAR benchmarks and assumed as indicators of a state of movement for the TZU\({}_{\text{road}}\) in Vaglio Basilicata (**b**) and Trivigno (**d**).  
As for the damages to the roads, several photos were collected and analyzed by exploiting the available Google Street View archive. Then, according to the adopted damage ranking (see Section 2.1.2), a damage severity level was assigned to the road stretch and then to the pertaining \(TZU_{road}\) (if covered). Figure 6 shows the results of the damage classification of the road stretches connecting highway SS407 Basilicaa to Vaglio Basilicaa (Figure 6a) and Trivigno (Figure 6b) urban centers. The chart reported in Figure 6c highlights the presence of damage along the investigated road stretches, with higher damage severity levels in the sections interacting with the slow-moving landslides. This confirms the slow but continuous movement of the mapped slope instabilities, causing damage to the exposed built-up environment whose severity progressively increases over time.