Land movement damage on the road between Petite Anse and Grande Anse, on Terre de Bas on Saintes Island (Guadeloupe, 2004). © BRGM - Séverine Bès de Berc

Natural geological risks

BRGM conducts research and expert studies on geological risks such as earthquakes, ground instability, cavity collapse, volcanic eruptions, shrinking and swelling of clay soils, etc.

Preventing and managing geological risks in a context of global change is one of the major concerns addressed by BRGM, through the following activities in particular:

  • Risk and vulnerability assessments in association with cartographic and risk management approaches;
  • Expert studies and support to the State and local government authorities;
  • Construction and management of databases on the main risks;
  • Delivery of data acquisition systems, surveillance systems and information facilities for the State and public operators.

Seismic and volcanic risks

BRGM works to improve understanding, assessments and management of seismic and volcanic risks, with a particular focus on:

  • Seismic risk assessments in mainland and overseas France and other countries;
  • Modelling seismic sources, wave propagation and soil responses;
  • Simulating the responses of built structures to earthquakes;
  • Setting up accelerometer networks to monitor seismic activity;
  • Expert studies and third-party expert assessments to support management of planning constraints or the construction of sensitive and listed facilities.
  • Seismic microzoning and risk mapping, including material, human and economic damage in France and elsewhere in the world;
  • Research on system vulnerability to earthquakes and volcanic eruptions;
  • Seismic emergency exercises to support the public authorities and development of automated crisis management tools;
  • Databases (e.g. SisFrance on the history of seismic events recorded in France, Neopal on recent deformations and paleo-events).

Ground instability and erosion

BRGM works on several types of risks arising from ground instability and erosion:

  • Rock falls (in mountainous terrain or from cliff erosion)
  • Landslides (slow-moving gravity landslips, ravine slides, mudslides)
  • Erosion (slopes and mass movements)
  • Clay shrinking and swelling

The aim is to understand, assess and support the management of risks arising from soil and slope instability by working to:

  • Understand and analyse the mechanisms involved in initiation and propagation, in the light of climate change scenarios in particular (increased rainfall intensity, melting glaciers, drought, etc.);
  • Develop economically realistic in situ measurement methods and modelling tools to investigate and monitor unstable zones;
  • Deliver modelling tools validated in pilot sites for the local scale, and risk assessment methods for deployment at regional scale.
  • Design surveillance systems for vulnerable regions, including overseas France, or strategically important zones.

Cavities and subsurface works

Subterranean cavities, whether natural or man-made, are a major public safety issue (sinkhole risks) and raise building constraints.

BRGM’s work in this area aims to support French central and local government authorities in developing sustainable planning policies, in particular:

  • by improving risk assessment (cavity location and size, fragility assessment, estimations of anticipated damage);
  • at different spatial scales ranging from the local area (mapping) to the cavity itself (diagnoses);
  • and on different time-scales: from the very short term (assessment of immediate danger and identification of early signs of collapse) to the medium or long term (estimating the probability of disturbances and their seriousness).
BRGM - 3 avenue Claude-Guillemin - BP 36009 45060 Orléans Cedex 2 - France Tel.: +33 (0)2 38 64 34 34