Laon: geology and natural hazards

Natural and technological hazards to which the commune is exposed, according to the national GASPAR database.

• Mouvement de terrain: affaissements et effondrements d’origine anthropique (anciennes carrières souterraines, hors mines)

18 events recognised as a natural disaster by ministerial order since 1986.

• Inondations et/ou coulées de boue: 13
• Mouvement de terrain: 5
• Sécheresse: 1

1. Mouvement de terrain

   Event on 26/12/2022, order published in the Journal officiel on 09/06/2024.

2. Mouvement de terrain

   Event on 28/10/2021, order published in the Journal officiel on 28/07/2023.

3. Inondations et/ou coulées de boue

   Event from 13/07/2021 to 15/07/2021, order published in the Journal officiel on 01/08/2021.

4. Sécheresse

   Event from 01/04/2020 to 30/09/2020, order published in the Journal officiel on 09/07/2021.

5. Mouvement de terrain

   Event from 04/04/2018 to 29/06/2018, order published in the Journal officiel on 09/08/2019.

6. Mouvement de terrain

   Event from 07/07/2001 to 16/12/2002, order published in the Journal officiel on 15/01/2005.

7. Inondations et/ou coulées de boue

   Event on 02/07/2000, order published in the Journal officiel on 15/11/2000.

8. Inondations et/ou coulées de boue

   Event on 11/05/2000, order published in the Journal officiel on 01/08/2000.

9. Mouvement de terrain, Inondations et/ou coulées de boue

   Event from 25/12/1999 to 29/12/1999, order published in the Journal officiel on 30/12/1999.

10. Inondations et/ou coulées de boue

    Event on 14/07/1997, order published in the Journal officiel on 28/03/1998.

11. Inondations et/ou coulées de boue

    Event on 27/08/1996, order published in the Journal officiel on 20/12/1996.

12. Inondations et/ou coulées de boue

    Event from 06/08/1995 to 07/08/1995, order published in the Journal officiel on 31/10/1995.

13. Inondations et/ou coulées de boue

    Event on 31/07/1994, order published in the Journal officiel on 25/09/1994.

14. Inondations et/ou coulées de boue

    Event on 23/07/1988, order published in the Journal officiel on 03/11/1988.

15. Inondations et/ou coulées de boue

    Event on 09/05/1988, order published in the Journal officiel on 14/01/1989.

16. Inondations et/ou coulées de boue

    Event on 22/06/1986, order published in the Journal officiel on 06/09/1986.

17. Inondations et/ou coulées de boue

    Event on 20/06/1986, order published in the Journal officiel on 06/09/1986.

18. Inondations et/ou coulées de boue

    Event on 17/06/1986, order published in the Journal officiel on 06/09/1986.

Seismic zone

Zone 1 of 5: very low. This regulatory zoning, in force since 2011, sets the rules for earthquake-resistant construction.

Radon potential

Category 1 of 3: low potential. The geological formations have the lowest uranium content. Radon is a naturally occurring radioactive gas that can build up in poorly ventilated rooms.

What BRGM maps say at the town hall. They describe that single point: elsewhere in the commune, the ground may be quite different.

• Shrink-swell clays

• Rising groundwater

• Underground cavities

• Ground movements

• Earthquakes

• Nature of the ground

Recorded across the whole commune by BRGM, in its national databases of underground cavities and ground movements.

58 underground cavities recorded (quarries, cellars, military works, natural cavities…).

117 ground movements recorded (landslides, rockfalls, collapses, mudflows…).

See cavities and ground movements on the map

• PPR - Laon

  Natural risk prevention plan.

The zoning and regulations of each plan, which may prohibit or restrict building, can be consulted at the town hall and on Géorisques.

• Chambry (02)
• Clacy-et-Thierret (02)
• Athies-sous-Laon (02)
• Besny-et-Loizy (02)
• Chivy-lès-Étouvelles (02)
• Cerny-lès-Bucy (02)
• Bruyères-et-Montbérault (02)
• Étouvelles (02)

Listed hazards, natural disasters, seismic zoning, radon potential, cavities, ground movements and prevention plans: Géorisques, published by the French ministry for the ecological transition, under Licence Ouverte Etalab 2.0, data accessed on 02/11/2026. Summary beneath the town hall: BRGM map services, queried when the page is displayed. List of communes and populations: API Découpage administratif (geo.api.gouv.fr), d’après le code officiel géographique de l’Insee, version of 30/10/2026.

This information reflects the state of knowledge at the scale of the commune or of a single point. It replaces neither a soil survey nor the official risk statement (état des risques) required for a sale or a rental, which is drawn up on the official French government service.