Pernes: geology and natural hazards

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

• Inondation: par une crue à débordement lent de cours d’eau, par ruissellement et coulée de boue, par remontées de nappes naturelles
• Séisme
• Transport de marchandises dangereuses

12 events recognised as a natural disaster by ministerial order since 1993.

• Inondations et/ou coulées de boue: 11
• Mouvement de terrain: 1
• Sécheresse: 1

1. Sécheresse

   Event from 31/12/2024 to 30/12/2025, order published in the Journal officiel on 13/04/2026.

2. Inondations et/ou coulées de boue

   Event on 24/07/2021, order published in the Journal officiel on 28/09/2021.

3. Inondations et/ou coulées de boue

   Event from 27/06/2021 to 29/06/2021, order published in the Journal officiel on 20/07/2021.

4. Inondations et/ou coulées de boue

   Event on 13/08/2015, order published in the Journal officiel on 29/10/2015.

5. Inondations et/ou coulées de boue

   Event on 19/07/2014, order published in the Journal officiel on 07/11/2014.

6. Inondations et/ou coulées de boue

   Event on 30/12/2012, order published in the Journal officiel on 25/05/2013.

7. Inondations et/ou coulées de boue

   Event on 03/06/2000, order published in the Journal officiel on 23/08/2000.

8. 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.

9. Inondations et/ou coulées de boue

   Event from 31/10/1998 to 04/11/1998, order published in the Journal officiel on 10/03/1999.

10. Inondations et/ou coulées de boue

    Event from 17/01/1995 to 05/02/1995, order published in the Journal officiel on 24/02/1995.

11. Inondations et/ou coulées de boue

    Event from 25/12/1994 to 31/12/1994, order published in the Journal officiel on 03/08/1995.

12. Inondations et/ou coulées de boue

    Event from 19/12/1993 to 02/01/1994, order published in the Journal officiel on 15/01/1994.

Seismic zone

Zone 2 of 5: 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.

No underground cavity recorded (quarries, cellars, military works, natural cavities…).

No ground movement recorded (landslides, rockfalls, collapses, mudflows…).

See cavities and ground movements on the map

• PPRi vallée de la Clarence

  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.

• Pressy (62)
• Floringhem (62)
• Marest (62)
• Sachin (62)
• Aumerval (62)
• Bailleul-lès-Pernes (62)
• Cauchy-à-la-Tour (62)
• Bours (62)

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.