Dunkerque: geology and natural hazards

Seismic zone

2 of 5 (low)

Radon potential

Category 1 of 3 (low potential)

Recognised natural disasters

25 since 1990

Underground cavities recorded

None

Ground movements recorded

None

Risk prevention plans

2

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

• Inondation
• Mouvement de terrain
• Séisme
• Risque industriel
• Nucléaire
• Transport de marchandises dangereuses
• Engins de guerre

25 events recognised as a natural disaster by ministerial order since 1990.

• Sécheresse: 15
• Inondations et/ou coulées de boue: 10
• Mouvement de terrain: 1

1. Sécheresse

   Event from 01/07/2022 to 30/09/2022, order published in the Journal officiel on 03/05/2023.

2. Sécheresse

   Event from 01/01/2022 to 31/03/2022, order published in the Journal officiel on 03/05/2023.

3. Sécheresse

   Event from 01/10/2018 to 31/12/2018, order published in the Journal officiel on 30/11/2019.

4. Sécheresse

   Event from 01/04/2011 to 30/06/2011, order published in the Journal officiel on 21/10/2012.

5. Sécheresse

   Event from 01/07/2009 to 30/09/2009, order published in the Journal officiel on 13/01/2011.

6. Inondations et/ou coulées de boue

   Event on 10/09/2005, order published in the Journal officiel on 11/03/2006.

7. Inondations et/ou coulées de boue

   Event on 10/09/2005, order published in the Journal officiel on 04/01/2007.

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

   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 on 07/05/1999, order published in the Journal officiel on 20/10/1999.

10. Inondations et/ou coulées de boue

    Event on 02/09/1998, order published in the Journal officiel on 13/01/1999.

11. Sécheresse

    Event from 01/01/1996 to 31/12/1996, order published in the Journal officiel on 18/01/2002.

12. Inondations et/ou coulées de boue

    Event from 17/01/1995 to 31/01/1995, order published in the Journal officiel on 03/08/1995.

13. Sécheresse

    Event from 01/01/1995 to 30/06/1997, order published in the Journal officiel on 28/03/1998.

14. Inondations et/ou coulées de boue

    Event from 27/07/1994 to 28/07/1994, order published in the Journal officiel on 31/01/1995.

15. 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.

16. Inondations et/ou coulées de boue

    Event from 17/12/1993 to 02/01/1994, order published in the Journal officiel on 18/02/1994.

17. Sécheresse

    Event from 01/10/1993 to 31/12/1996, order published in the Journal officiel on 11/10/1997.

18. Sécheresse

    Event from 01/01/1993 to 30/09/1993, order published in the Journal officiel on 09/09/1995.

19. Sécheresse

    Event from 01/01/1993 to 31/12/1997, order published in the Journal officiel on 11/12/1998.

20. Sécheresse

    Event from 01/01/1992 to 31/12/1992, order published in the Journal officiel on 09/07/1994.

21. Sécheresse

    Event from 01/01/1992 to 31/12/1993, order published in the Journal officiel on 14/02/1996.

22. Inondations et/ou coulées de boue

    Event on 14/11/1991, order published in the Journal officiel on 23/08/1992.

23. Sécheresse

    Event from 01/01/1991 to 30/09/1992, order published in the Journal officiel on 03/09/1993.

24. Sécheresse

    Event from 01/01/1990 to 31/12/1990, order published in the Journal officiel on 30/08/1991.

25. Sécheresse

    Event from 01/01/1990 to 31/12/1991, order published in the Journal officiel on 18/08/1992.

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

• PPRL Dunkerque Bray-Dunes

  Natural risk prevention plan.

• PPRT Zone Industrialo-Portuaire

  Technological 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.

• Coudekerque-Branche (59)
• Téteghem-Coudekerque-Village (59)
• Cappelle-la-Grande (59)
• Leffrinckoucke (59)
• Grande-Synthe (59)
• Armbouts-Cappel (59)
• Uxem (59)
• Bierne (59)

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.