Roads and landslide terrain.
Where Silvi's roads cross terrain mapped as landslide-affected, and when rainfall approaches scientific thresholds.
What updates and what does not. The map, the kilometres and the colours below are static: they come from official maps that rarely change, and we redo them only when the Region revises them. We have not checked whether these maps take into account the 2026 movements at Silvi Paese (see Territory). Only the "Recent rainfall" box is live and refreshes on every visit to the page.
Recent rainfall
Calculating…
We compare the rain of the last hours (Open-Meteo model, at the centre of the Municipality) with the scientific landslide-triggering curves for Abruzzo (Brunetti et al., 2010, 5% threshold: E = 5.94 · D0.45, E in mm and D in hours). Exceeding it does not mean anything will slide: it means that, in the past, rainfall of this size has been associated with landslides in the region.
Model or rain gauge? The rain above is calculated by a weather model, not measured on the spot. Measured data from the regional network are held by the Abruzzo Functional Centre (AllarMeteo).
Map
The colour of each 100-metre stretch shows how much the 50-metre strip around the road overlaps terrain already mapped as landslide-affected, steep or eroded. It does not indicate ongoing movement, nor that the road is unstable. Many mapped areas are old or dormant.
Roads with the most kilometres in mapped areas
| Road | km in mapped areas |
|---|---|
| Strada Statale 553 di Atri | 3.02 / 6.59 |
| Autostrada Adriatica | 2.13 / 15.41 |
| SP29b | 2.04 / 3.45 |
| Contrada Cerrano | 1.07 / 3.19 |
| Strada Provinciale Montesilvano Atri | 0.72 / 3.09 |
| Contrada Stagliano | 0.61 / 0.94 |
| Contrada Santo Stefano | 0.44 / 2.18 |
| Contrada Fosso del Gallo | 0.44 / 1.45 |
| Via Ambrogio Rossi | 0.3 / 0.61 |
| Via San Silvestre | 0.28 / 1.0 |
What is not in this table. Unnamed dirt tracks (country tracks): 16.3 km out of 47.1 cross mapped areas. We do not rank them because they have no name, and they are not coloured on the map (the index excludes them); but they count in the totals above. Source of the counts: OpenStreetMap crossed with the official landslide maps. Provincial road 29/b, cited in the Municipality's orders on the Silvi Paese landslide, appears in the table under the name "SP29b" as OpenStreetMap records it.
Is the ground moving? Radar satellites
The European service EGMS (Copernicus) measures from radar satellites by how many millimetres a year thousands of fixed points, such as roofs, walls and asphalt, rise or sink. For Silvi we have not yet looked at or computed anything: in built-up areas there are many points, but where the ground is bare or covered in vegetation the radar finds few or none, and "no point" does not mean "no movement". The official viewer can be consulted freely. The data are updated once a year: they cannot tell what is happening today.
How it is computed
- Landslide areas: IFFI inventory (ISPRA) and the Abruzzo Region geomorphological map, "landslide movements" layer.
- Slope: Copernicus GLO-30 terrain model (30 m). It underestimates scarps and roads on embankments.
- Badlands and erosion: regional geomorphological map and modelled erosion (Abruzzo Region). In Silvi very few badlands are mapped (5 ha).
- Roads: OpenStreetMap, farm tracks excluded from the index. Municipal boundary: ISTAT.
- Index:
0.30·slope + 0.35·landslide area + 0.15·badlands + 0.20·erosion, weights chosen by judgement and not calibrated on events (the same used for Atri). Low below 0.25; medium from 0.25; high from 0.5.
Limits
The maps are official but not updated in real time and we do not know whether they include the 2026 movements; the rain is from a model, not a rain gauge; the index is not calibrated and is not a probability. For Silvi we have not compared the thresholds with past events: we cannot say how reliable they are in this area.
Seen a road collapse or landslide?
Report it by marking the spot on the map and describing what you saw (photos cannot be attached yet): it helps check whether the map matches reality. In case of immediate danger call 112. Go to Reports
Data: roads · mapped areas. Processed on 2026-10-26.