Which towns have the largest share of territory in landslide class P3/P4?
Among municipalities with at least 20,000 residents and provincial capitals, Gragnano has the highest share of territory with landslide hazard P3 or P4: 61.8%, according to ISPRA’s mosaic v5.0 (2024), IdroGEO indicators read on 25 October 2026.
The ranking
| Municipality | Territory P3-P4 | Residents in P3-P4 | Residents 2021 |
|---|---|---|---|
| Gragnano (NA) | 61.8% | 16.6% | 28,167 |
| Vico Equense (NA) | 54.2% | 18.2% | 20,363 |
| Cava de' Tirreni (SA) | 49.4% | 10.5% | 51,067 |
| Mercato San Severino (SA) | 45.3% | 9.9% | 21,679 |
| Pontassieve (FI) | 45.3% | 12.5% | 20,304 |
| Castellammare di Stabia (NA) | 43.9% | 4.5% | 63,330 |
| Sarno (SA) | 43.4% | 3.6% | 30,652 |
| Nocera Superiore (SA) | 40.3% | 4.8% | 23,842 |
| Rapallo (GE) | 38.3% | 4.4% | 29,107 |
| Ariano Irpino (AV) | 35.9% | 8.4% | 21,240 |
| Sora (FR) | 33.7% | 10.5% | 25,059 |
| Camaiore (LU) | 31.2% | 18.1% | 31,821 |
| Genova (GE) | 31.2% | 5.4% | 561,203 |
| Capannori (LU) | 30.3% | 7.6% | 46,390 |
| Figline e Incisa Valdarno (FI) | 29.2% | 10.9% | 23,219 |
| Sondrio (SO) | 28.6% | 1.7% | 21,192 |
| Somma Vesuviana (NA) | 28.3% | 4.6% | 33,935 |
| Montevarchi (AR) | 27.5% | 5.2% | 24,047 |
| Lucca (LU) | 27.4% | 5.1% | 89,078 |
| Iglesias (SU) | 27.3% | 3.7% | 25,382 |
| Massa (MS) | 27.3% | 8.8% | 66,498 |
| Ottaviano (NA) | 27% | 2% | 23,064 |
| Chiavari (GE) | 25.7% | 5.8% | 27,228 |
| Sanremo (IM) | 24.7% | 27.6% | 52,918 |
| Pozzuoli (NA) | 24.2% | 7.8% | 76,952 |
| Sant’Anastasia (NA) | 23.8% | 0.9% | 26,460 |
| Nocera Inferiore (SA) | 23.7% | 1% | 44,331 |
| Lecco (LC) | 23.3% | 1.1% | 46,831 |
| Massarosa (LU) | 23.1% | 16.2% | 21,823 |
| Valsamoggia (BO) | 22.8% | 3.1% | 31,605 |
| Salerno (SA) | 22.6% | 3.4% | 128,136 |
| Teramo (TE) | 22.4% | 3.2% | 51,849 |
| Lanciano (CH) | 21.6% | 5.5% | 34,201 |
| Marano di Napoli (NA) | 21% | 3% | 58,042 |
| Carini (PA) | 20.6% | 2.2% | 39,275 |
| Caserta (CE) | 20.6% | 6.2% | 73,037 |
| Sesto Fiorentino (FI) | 19.9% | 1.3% | 48,782 |
| Montecatini-Terme (PT) | 19.6% | 2.9% | 20,468 |
| Bagno a Ripoli (FI) | 18.8% | 4.4% | 25,314 |
| Livorno (LI) | 18.8% | 1.4% | 154,483 |
| Carrara (MS) | 18.7% | 6.4% | 60,185 |
| Campobasso (CB) | 18.4% | 5.7% | 47,587 |
| Nuoro (NU) | 18% | 5.5% | 34,183 |
| Bolzano (BZ) | 17.2% | 2.1% | 106,601 |
| Chieti (CH) | 17.2% | 14.8% | 48,666 |
| Formia (LT) | 16.9% | 3.5% | 37,278 |
| Castel San Pietro Terme (BO) | 16.7% | 1.1% | 20,666 |
| Cesena (FC) | 15.5% | 1.4% | 96,168 |
| Aosta (AO) | 15.5% | 1.1% | 33,223 |
| Sessa Aurunca (CE) | 15.4% | 6.6% | 20,366 |
Share of the municipal area in classes P3 and P4 of the national landslide mosaic (v5.0, 2024) and share of 2021 census residents living there. Processing: SRI Group BV (VAT BE1037052239).
Other data often matter for the same property too, such as the municipalities most exposed to floods and the location data. You can see how a dossier brings them together in the sample dossier.
How to read it
It is the share of the municipal area in class P3/P4, not a measure of how ‘dangerous’ a town is, and it does not say whether a house is in a hazard area. Population: towns with at least 20,000 residents (2021 census) and provincial capitals; ordered by decreasing share, ties by name. Dataset: ISPRA mosaic v5.0 (2024), IdroGEO indicators read on 25 October 2026.
Sources
Dossier Immobile is a private service by SRI Group BV (VAT BE1037052239), not connected to any public authority: it brings together public data, with the source and date of every item.
Updated on