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Risks and spatial planning

Flagship project / Combating natural risks around the world

Introduction d'entête
Whether they be floods, earthquakes, tsunamis, landslides... natural and climatic risks are a major challenge for populations in many parts of the world. BRGM applies its multi-risk expertise to numerous international projects. Here we take a look back at three representative projects in Madagascar, Malawi and Mauritius.

What can be done to better understand and take account of risks in order to improve spatial planning in vulnerable areas or manage crises? Recent events have shown us the extent to which certain parts of the world are vulnerable: the Caribbean, Africa and the Indian Ocean have all regularly suffered from catastrophic events; natural risk prevention is essential here to safeguard infrastructures and protect populations.

Examining an outcrop in Malawi as part of the GEMMAP project to produce a multi-hazard map.
© BRGM - M. Terrier

For several years now, BRGM’s Risk and Prevention Department has been providing multi-risk expertise to international projects in various parts of the world. In addition to the knowledge acquired from field missions, the teams of scientists use software to better understand cataclysms such as floods, earthquakes and tsunamis, and to assess hazards. They also develop specific risk-display tools.
BRGM therefore regularly deploys its international know-how in operational applied science and training. This is reflected in three studies carried out in 2019.

What sequence of preventive measures is needed for natural risks?

Prevention consists in anticipating problems before they occur as disasters, in order to reduce the likelihood of natural risks and their consequences. The sequence of preventive measures extends from informing populations and training local stakeholders through to creating surveillance and early warning tools, and also comprises knowledge of the phenomena and the risks involved, spatial planning, reducing vulnerability (mainly through building standards) and preparing for crisis management.
BRGM therefore created a geological map of natural risks in Malawi, worked on improving knowledge of seismic and tsunami hazards in Mauritius, and produced an atlas of natural and climatic risks in Madagascar.

Three representative projects

— Malawi: in south-east Africa, BRGM is closely involved in the GEMMAP project (Geological Mapping and Mineral Assessment of Malawi) that began in 2016, within the framework of economic development and prevention policies. In 2019, experts completed a survey of the different phenomena and an assessment of ground instability, floods and active faults in order to create a multi-hazard map of the entire country at scales of 1:250,000 and 1:1,000,000. The aim was to produce a homogeneous document for the government and provide a tool for informing the population about natural risks.

— Mauritius: seismic and tsunami hazards were assessed in the Mauritius region of the Indian Ocean. This mission ended with recommendations being made to the Mauritius government on improving resilience to counter these threats. BRGM conducted a vulnerability study in order to identify risks based on the latest knowledge, assess the potential impacts of tsunamis and earthquakes, and make recommendations.

— Madagascar: lastly, in early 2019, climate change training was provided to some thirty local managers in Madagascar. An atlas of natural and climatic risks was also created for the entire island. These risks include cyclones, floods, ground instability, coastal erosion, marine submersion and drought. The study led to publication of an information and awareness-raising document aimed at all audiences (engineering consultancies, local authorities, schools, media); it included risk maps at a scale of 1:4,000,000 and an explanatory section with definitions, historical events, ongoing studies, etc. An easy-to-use software package was also developed for displaying and using these maps and data, and a specific module is being developed for it in QGis. As well as enabling visualisation of data, it displays cyclone risk forecasts. It is a tool for both spatial planning and crisis management. Malagasy engineers have been trained to use it, and to update the database with knowledge acquired in the future.

Fallen boulders at the foot of the cliff and soil erosion (lavakas) at the bottom of the slopes in Madagascar’s Isalo massif. © BRGM - M. Terrier
Map of ground instability hazards in Madagascar. © Atlas des risques naturels et climatiques de Madagascar

These three projects, which are being supported by international donors, form part of the risk prevention policies implemented by the respective governments.

Engineers involved in the studies mentioned: Madagascar > R. Bélon, A. Maspataud, D. Allier, A. Brugeron, S. Pinson, O. Sedan, B. Le Moigne; Malawi > Y. Thiery, M. Garcin; Mauritius > D. Bertil, S. Leroi.

Portrait de l'auteur
Monique Terrier — Géologue, experte senior en Risques naturels
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Senior expert in natural risks
Madagascar, Malawi, Mauritius: meeting operational needs for natural risk prevention at the international level.