Carte géologique de la région Occitanie.
BRGM Occitanie has a Regional Division in Montpellier and a Regional Delegation in Toulouse, with 22 staff providing all BRGM’s key roles in collaboration with the Scientific and Technical Centre in Orléans. There is also a BRGM Research Unit in Montpellier focusing on “New Water Resources and Water Economics”. With 17 staff, this decentralised unit of BRGM Orléans investigates alternative options to conventional water resources, which are under increasing pressure.
A region of sharp contrasts
Occitanie is the second largest region in mainland France, with thirteen départments. It has a population of 5,830,166, attracting 50,000 new inhabitants every year.
The region consists of four strongly contrasting geographical areas with distinct challenges: the Pyrenees, the Mediterranean coastline, the plateaux and foothills of the Massif Central, and the Toulouse urban area and its galaxy of smaller regional towns.
The region’s economic, educational and spatial planning goals have been set out in several plans: the Regional Master Plan for Economic Development, Innovation and Internationalisation (SRDEII), the Regional Master Plan for Spatial Planning, Sustainable Development and Territorial Equality (SRADDET), and the Regional Master Plan for Higher Education, Research and Innovation (SRESRI), to all of which BRGM contributes its expertise in its core areas of specialisation.
As part of its major role supporting local and regional authorities, BRGM is focusing its efforts on water in particular, with the Regional Strategy on Water, as well as on natural hazards, the Coastal Plan 21 (Plan Littoral 21), and geothermal energy (with the REPOS approach towards energy self-sufficiency for the region).
A group of public and private partners
BRGM has experience of partnerships for projects that support public policy, public and private research for responding to the needs of industry, and of training at all levels of decision-making and regional planning. It works with public partners: Europe (ERDF, INTERREG), the Prefectures, DREAL, DDT(M), DRRT, Pyrenean Mountains Commission, DRAAF, ANR, ADEME, AFB, ARS, Regional Council, Departmental Councils, metropolitan, district and municipal councils (e.g. Toulouse, Montpellier 3M, Perpignan M, Béziers Agglo, Thau Agglo, Le Grand Tarbes, le Grand Montauban), Adour-Garonne and Rhône-Méditerranée-Corse water agencies, syndicates (e.g. SMEAG, SMDEA, SMAGE des Gardons, SMBT), chambers of agriculture, Cévennes National Park, Pyrenees National Park etc.; and many scientific partners: University of Montpellier (Hydrosciences and Geosciences UMRs), UMR G-eau, ISITE MUSE, Institut Montpelliérain de l'Eau (IM2E), CNRS, IRD, IRSTEA, IFREMER, Paul Sabatier and Jean Jaurès Universities, Observatoire Midi-Pyrénées (OMP), OPCC, Météo-France, CERFACS, INRA, INPT.
BRGM is a member of the AQUAVALLEY and DERBI competitiveness clusters, the PVSI cluster and the TERINOV cluster, and collaborates with private companies (e.g. IMAG'EAU, KLOE, SYNAPSE, YELLOW SCAN, BRLi, Predict Services, Groupe FABRE and DANONE) on developing methods for research, development and innovation in support of their fields of activity.
What's new in Occitanie region?
Water resources: addressing growing needs
With river flows reducing in large rivers due to climate change, groundwater offers an alternative water resource for the supply of drinking water as well as agricultural and industrial uses. The supply of drinking water is a major concern in the region, which attracts 50,000 new inhabitants each year and more than 30 million tourists.
In 2018, the Occitanie Region adopted a Regional Water Strategy to address this issue and the challenges of conflicts of use, flood risk, low water replenishment and biodiversity conservation. This strategy is one of the focal points of the Master Plan for Water Development and Management (SDAGE) of the Adour-Garonne and Rhone-Mediterranean-Corsica catchment basins.
Reconnaissance hydrogéologique des calcaires de Bentaillou en Ariège (Bentaillou, 2015).
BRGM's involvement and responses
The Occitanie Region has significant groundwater resources that are widely exploited, particularly in the former Languedoc-Roussillon region where 90% of drinking water comes from groundwater. Groundwater resources can still be used extensively provided there is a good understanding of their natural processes and vulnerability to urban pollutants (e.g. emerging pollutants) and diffuse agricultural contaminants (e.g. nitrates and pesticides). On the coastline, sea level rise coupled with the potential decrease in rainfall makes aquifers vulnerable where needs are greatest (e.g. increased salinity of the Roussillon aquifer). Surface water is heavily used in floodplains and proactive management of groundwater – for the replenishment of rivers when their water level drops – is a major issue that needs addressing.
BRGM conducts long-term work to observe groundwater levels and pollution (using piezometric and nitrate and pesticide monitoring networks), understand groundwater flows (in karstic environments, e.g. Nîmes, Corbières, Sault and Lez, and in basement and volcanic environments, e.g. Margeride, Aubrac and the Pyrenees), assess resources and recharging conditions (e.g. GMU-Lez programmes for the greater Montpellier area, modelling of the alluvial aquifers of the Garonne and Ariège rivers for the DDTs and SMEAG, work on the Sault plateau and on Corbières, and support for the Adour-Garonne Climate Change Adaptation Plan), and investigate pesticide and emerging pollutant transfers (TRANSPOLLAR and ELISE programmes for the Ariège aquifer).
BRGM helps disseminate and develop data on water, in particular through the SIGES Midi-Pyrénées information system for mapping, databases and documentation, whose extension to the new Occitanie boundaries is being considered.
- Occitanie is France’s leading region for geothermal springs. BRGM provides its expertise and knowledge of geothermal and mineral water resources to support the development and conservation of this unique asset.
Natural hazards: flood, coastal, seismic and landslide hazards
The Occitanie Region is subject to all types of natural hazards: ground movement, earthquakes, coastal erosion, flooding, avalanches, and forest fires. Climate change can influence the occurrence and magnitude of these phenomena in a variety of ways.
Dégâts suite au glissement de Gazost : habitation détruite (Hautes-Pyrénées, 2015).
© BRGM - Isabelle Bouroullec
BRGM's involvement and responses
BRGM assists local and regional authorities and government departments in assessing events, understanding their causes and, if possible, in predicting them by developing tools and simulations. It is also responsible for disseminating information on natural risks (e.g. BD-MVT, BD-Cavités) via GéoRisques.
The region is subject to intense rainfall events (e.g. torrential rain in the Cévennes) and coastal erosion, and is particularly exposed to the risk of flooding (e.g. 13 people were killed in the autumn of 2014). It is estimated that 600,000 to 1 million people live permanently in a flood risk area in the Languedoc-Roussillon basin.
In the Adour-Garonne basin, 20% of the population and 82% of communes are also exposed to flood risk.
From a prevention perspective, government departments and local authorities are looking ahead and implementing the new governance plans drawn up for managing aquatic environments and preventing flooding (GEMAPI).
In some catchment areas, such as Nîmes, Lez, Agly and Cesse, BRGM has shown that groundwater levels played a key role in flooding intensity.
As part of collaborative projects (e.g. the KRHU project with Predict Services, the Ecole des Mines at Alès – EMA, Synapse and Ceneau), it has developed indicators to use groundwater levels as a source of flood forecasting information (Karst indicator).
The tool, which has been successfully used for the Lez river (see below) and the Fontaine de Nîmes spring, may be tested and implemented in other catchment areas.
The GMU Lez Project (water from the coastal Lez river in the Hérault département is abstracted at the river’s source to supply water to 340,000 residents) was based on a comprehensive study of groundwater flows, a quantitative, qualitative and ecological assessment of the water resource and an assessment of the aquifer’s role in Lez flooding.
The project outcomes included:
- A change to the outer groundwater source protection zone for the Lez, to increase protection;
- Simulations of the impact of climate change on the source by 2050;
- Testing of pumping scenarios to improve the management of this reservoir;
- The development of a tool to assist in setting up a 24-hour flood-warning system based on the karst saturation status.
The doubling of the coastal population in the last forty years is a key economic issue. The Coastal Plan 21 was drawn up by the Region and the French Government to provide a boost to the maritime and coastal economy. BRGM is contributing to this plan, in particular to its section on “Taking account of coastline erosion and adapting uses to climate change”.
BRGM is providing its expertise in coastal development and protection. It has been establishing sandy coastline observatories in collaboration with several partners, including PMM, Thau Agglo and DREAL and is helping disseminate information and data.
Its R&D work, mostly carried out with partners, focuses on:
- Coastal erosion and the landward retreat of the coastline (observation, assessment, quantification);
- Assessment of coastal flooding and its link to climate change through modelling;
- Geology and geophysics for estimating coastal sedimentary stocks;
- Forecasting of phenomena and impacts;
- Integrated management (including socio-economic approaches).
On the Lido beach in Sète, BRGM is monitoring coastal erosion prevention trials using digital video. This programme (2011–2019) is based on real-time, high-frequency monitoring of the morphology of coastal areas of “economic interest”.
The Pyrenean chain is classified as a zone of moderate seismicity – the highest seismicity in mainland France – where major earthquakes could occur, with potential costs of up to 6 to 8 billion euros. Because earthquakes are so unpredictable, the only strategy is prevention, emergency relief planning, and improving disaster resilience. In partnership with regional bodies and Catalan and Andorran institutes, BRGM is developing methodologies for automatic scenarios of cross-border damage in real time as part of the INTERREG programmes (ISARD – SISPYR). It is contributing to the Seismic Information System on the Pyrenees, developed under these programmes to provide real-time information about earthquakes, which occur every year in the Pyrenees.
BRGM is providing scientific support to DREAL Occitanie to apply the National Framework of Action for Preventing Seismic Risk (CAPRIS) in the Pyrenees. Its objective is to develop a seismic risk prevention strategy and an associated action plan, as well as appropriate governance tools. The CAPRIS framework brings together government departments, local and regional authorities, community organisations and practitioners.
Drought and clay soil shrinking and swelling hazards
The shrinking and swelling of some clay soils due to severe drought causes significant damage to buildings, sometimes leading to collapse. Compensation of victims through the CatNat scheme represents the second biggest expense for hazards after flooding. BRGM has produced maps for this hazard. The Haute-Garonne and Gard départements are particularly susceptible to this risk, which can have significant consequences. New tools and methods are currently being explored.
An ambitious energy goal at the European level
In a context of strong economic and demographic growth, energy transition is a major challenge for the Occitanie Region, whose stated objective in its 2017 Regional Strategy was to be the first European region to become energy self-sufficient, with a 150% increase in renewable energy by 2050.
Cartes de potentiel géothermique dans l’ex-région Midi-Pyrénées et dans les départements du Gard et de l’Hérault.
BRGM's involvement and responses
The region has a huge potential for renewable energies, including solar, wind and geothermal.
The outlook for developing geothermal energy is very good, as shown by BRGM’s geothermal potential maps of the former Midi-Pyrénées region and Gard and Hérault départements.
However, the structure and expertise of the geothermal energy sector should be strengthened, and the public’s awareness of it should be raised.
Waste heat recovery from the Pyrenean spas represents another potential area for heat generation.
Lastly, BRGM is working with public laboratories and companies to investigate and develop the underground storage and release of thermal energy from solar panels and greenhouses (projects with FCS, ANR, ERDF, Regional Council and ADEME).
Promoting the region’s geological heritage and regional planning
Most environmental and spatial planning issues cannot be properly addressed without a good knowledge of the subsurface. The nature of the subsurface has a direct bearing on many issues, including the heritage value of the region's geological diversity, its material and mineral resource needs, and the presence of multiple industrial wastelands and contaminated sites and soils in major cities.
Vues des pics du Néouvielle et du Ramoun (Hautes-Pyrénées).
BRGM's involvement and responses
BRGM is providing public access to all available geological knowledge by publishing geological maps at a scale of 1:50,000 as well as 65,000 drilling and borehole records from the subsurface database (BSS, available on BRGM's InfoTerre portal).
BRGM is responding to the region’s increasing mapping needs (e.g. local planning maps and geological and hydrogeological maps) and has partnered with the PICTO initiative, a government mapping portal for Occitanie, which provides stakeholders with official geographical reference data.
The Occitanie Region’s geological diversity has unique value for the natural and cultural heritage of France and Europe. Since 2008, an inventory of the most remarkable sites has been undertaken in partnership with DREAL.
This tool serves to promote regional areas of interest, as Occitanie is France’s fourth region for tourism, with eight UNESCO World Heritage sites and nine national parks and nature reserves.
BRGM assists local and regional authorities in the management of contaminated sites and soils, sediments and excavated earth. It shares its expertise in developing innovative methodologies for the management of complex sites.
It carries out urban historical inventories (IHUs) to provide local and regional authorities with decision-support tools for the recovery and sustainable rehabilitation of industrial and urban wastelands.
BRGM undertakes third-party expert investigations on site remediation projects and monitors the application of remediation procedures.
- Identification and databanking of information on past and present mineral resource development activities
- Research on the origin of the building and decorative stones of regional emblematic monuments
- Identification and characterisation of primary resources (revision of the Regional Quarry Master Plan)
- Construction waste management: ASURET project, to address the needs of local and regional authorities dealing with demolition waste