HAL-BRGM, les publications scientifiques en libre accès du BRGM
Not a member yet
14098 research outputs found
Sort by
Is Collaborative Groundwater Governance Really Unfit for Purpose in Low-and Middle-Income Countries? Evidence from Morocco
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616925/) * Autres projets (id;sigle;titre): ;eGROUNDWATER;(EU) Citizen science and ICT-based enhanced information systems for groundwater assessment, modelling and sustainable participatory management// 101102316;ERA-LEARN;(EU) Strengthening the European Partnership community//International audienceAttempts to establish collaborative groundwater governance (CGG) have so far generally produced limited results in low-and middle-income countries. These shortcomings have been attributed to the high transaction costs associated with such approaches, making them impractical in informal water economies. This paper examines the obstacles to designing and implementing such an approach, through the analysis of a multistakeholder process conducted in a groundwater-depleted area in Northern Morocco. The process brought together farmers, staff members of public organisations, and other stakeholders to explore options for CGG. During the process, farmers created groundwater users associations and together the participants drafted an aquifer contract. The participatory process helped overcome several obstacles to CGG, particularly those related to farmers' engagement. The finalisation of the aquifer contract was put on hold, however, due to the limited follow-up by state actors, the insufficient coordination among the numerous public actors involved, and weak political support.The study shows that CGG may not be inherently unfit for purpose in at least some low-and middle-income countries. Moreover, the participatory design of CGG can be an opportunity for horizontal dialogue between farmers operating in informal water economies and state administrations
Hydro-Economic Mapping of Groundwater Potential in the Kunene and Omusati Regions, Namibia
No full textInternational audienceThis study focuses on mapping groundwater potential in Namibia's Kunene and Omusati regions that face severe water scarcity due to arid conditions and limited surface water. The research integrates hydrogeological data, water quality assessments, recharge projections, and economic feasibility to create a spatial framework for sustainable water resource planning. Kunene, dominated by hard rocks, has limited aquifer potential, while Omusati, part of the Cuvelai-Etosha Basin, contains thicker sedimentary aquifers but suffers from poor groundwater quality, particularly high salinity and nitrate levels. A revised 1:250,000-scale aquifer potential map was developed using geological data, borehole yields from the GROWAS II database, recent studies, and fieldwork. Water quality was analyzed using major ions, fluoride, nitrate, and salinity, with a Water Quality Index (WQI) identifying high-risk areas. Sustainable groundwater yield and aquifer potential were assessed, incorporating climate change projections that indicate future declines in recharge, especially in Omusati and southeastern Kunene. Demand projections for urban and rural areas were combined with infrastructure cost estimates to assess the economic feasibility. The resulting water-resource opportunity map highlights areas where groundwater or surface water is viable, emphasizing the challenges faced by urban centers like Opuwo and Khorixas. While rural areas generally remain resource-positive due to low demand, the study underscores the need for site-specific investigations and improved data quality to support long-term planning in this water-stressed region.Cette étude se concentre sur la cartographie du potentiel d'eaux souterraines dans les régions de Kunene et d'Omusati en Namibie, qui sont confrontées à une grave pénurie d'eau en raison de conditions arides et d'une disponibilité limitée d'eau de surface. La recherche intègre des données hydrogéologiques, des évaluations de la qualité de l'eau, des projections de recharge et la faisabilité économique afin de créer un cadre spatial pour la planification durable des ressources en eau. Kunene, dominée par des roches dures, présente un potentiel d’aquifère limité, tandis qu’Omusati, faisant partie du bassin Cuvelai‑Etoša, possède des aquifères sédimentaires plus épais mais souffre d’une mauvaise qualité de l’eau souterraine, notamment une forte salinité et des niveaux élevés de nitrates. Une carte révisée du potentiel des aquifères à l’échelle 1 : 250 000 a été élaborée à partir de données géologiques, de rendements de puits provenant de la base de données GROWAS II, d’études récentes et de travaux de terrain. La qualité de l'eau a été analysée à l'aide des principaux ions, du fluorure, du nitrate et de la salinité, avec un indice de qualité de l'eau (IQE) identifiant les zones à haut risque. Le rendement durable des eaux souterraines et le potentiel des aquifères ont été évalués, en intégrant les projections du changement climatique qui indiquent des diminutions futures de la recharge, notamment à Omusati et dans le sud‑est du Kunene. Les projections de la demande pour les zones urbaines et rurales ont été combinées aux estimations des coûts d'infrastructure afin d'évaluer la faisabilité économique.La carte des opportunités en ressources hydriques qui en résulte met en évidence les zones où les eaux souterraines ou de surface sont viables, soulignant les défis auxquels sont confrontées les villes comme Opuwo et Khorixas. Alors que les zones rurales restent généralement positives en ressources grâce à une faible demande, l'étude souligne la nécessité d'enquêtes spécifiques au site et d'une amélioration de la qualité des données pour soutenir la planification à long terme dans cette région soumise à la pénurie d'eau
Structural Accommodation as a Coastal Adaptation Response to Sea‐Level Rise: Lessons From Europe
No full textInternational audienceGlobal sea-level rise is intensifying pressures on coastal regions, increasing the need for adaptation strategies (e.g., protect, retreat, accommodate). At the same time, decision makers require a better understanding of the available responses to address the widening adaptation implementation gap. Structural measures aimed at reducing the impacts of coastal hazards as part of the accommodation strategy have received limited attention in the coastal adaptation literature with few studies looking at how it is currently considered to address sea-level rise. We first advance a conceptual framework that separates structural from non-structural accommodation, recognizing that this distinction is essential to accurately define the adaptation "solution space." Building on this framework, we synthesize scientific and gray literature, conduct a multilevel review of policy and technical documents, and draw on expert input to not only evaluate the current state of structural accommodation in Europe but also to highlight generic lessons for its potential implementation. This includes consideration of its advantages and disadvantages. Uptake remains fragmented and highly localized, embedded mainly in municipal spatial planning rather than national adaptation agendas, and is hampered by financial, institutional, and technical constraints. We argue that stronger policy integration and dedicated financial incentives could overcome these barriers and harness accommodation's value as a flexible option capable of reducing risk and avoiding long-term lock-in. This study improves our understanding of how this strategy can contribute to coastal resilience in Europe and beyond. Plain Language SummaryAs sea levels rise coastal communities around the world need new ways to adapt and stay safe. One approach is to elevate homes or vulnerable parts of buildings above predicted flood levels, referred to here as "structural accommodation." While these types of measures are common in the United States, Southeast Asia, and some small islands, their role in Europe is poorly understood. In this study, we reviewed scientific research, government policies, and expert insights to clarify what structural accommodation means, examine where and how it is being implemented, and identify the conditions under which it can be most useful. We found that its use varies widely across Europe, is generally limited to local projects, and is often overlooked in national adaptation policies. This lack of integration with other adaptation strategies may hinder the planning of a long-term response to sea level rise. Although our focus is on Europe, the lessons on the benefits, challenges, and limits of structural accommodation are relevant for coastal adaptation worldwid
Storm Wind Flow and Sediment Dynamics on Adjacent Coastal Dunes With Contrasting Morphologies During One Storm Event
No full textInternational audienceThis study presents the first high‐resolution spatial and temporal analysis of wind flow, sediment transport and topographic evolution under simultaneous storm conditions across two morphologically contrasting beach‐dune systems, characterized by a gently sloping dune face (11°) and a steep, scarped dune face (36°). Results demonstrate that the dune slope strongly controls near‐surface wind acceleration, the development of secondary airflow structures (amplitude, spatial positions), and the continuity of sediment transport pathways. Over the gentle slope, airflow accelerates progressively up the stoss face, promoting sustained, landward‐directed sediment fluxes across the entire beach–dune system and enabling efficient sediment recycling. In this configuration, beach‐derived contributions account for only 12%–15% of the total sediment flux. In contrast, the steep scarp induces flow deceleration and separation at the dune toe, limiting sediment transfer from the beach and favoring seaward‐directed transport associated with secondary vortices at the crest. These contrasting airflow organizations result in fundamentally different storm responses. The gently sloping dune undergoes landward translation with minimal net volume change, whereas the scarped dune experiences dominant marine erosion, leading to a 4 m retreat of the dune front and a sediment loss of ∼30 m 3 m −1 . A new conceptual model of storm‐driven airflow over contrasting dune morphologies is proposed, illustrating how inherited dune slope governs airflow structure and circulation patterns. Overall, these results identify inherited dune morphology as a primary control on airflow organization, sediment pathways, and dune resilience during extreme events
Potentiel de récupération du Vanadium dans les laitiers sidérurgiques en Europe
No full textInternational audienceFace aux enjeux de la mondialisation et des risques d’approvisionnements en métaux critiques, la mine urbaine émerge comme un gisement alternatif prometteur au double avantage; en plus de répondre à la demande de matériaux, elle optimise également leur usage, réduisant potentiellement l’impact environnemental de la production de matériaux. Parmi les gisements secondaires de potentiel intérêt, les laitiers sidérurgiques sont susceptibles de contenir des métaux critiques dont la valorisation en tant que métal n’est pas faite au niveau industriel aujourd’hui. En effet la littérature [5-12] montre que les laitiers de convertisseurs, peuvent avoir une teneur intéressante en vanadium (jusqu’à 2.7% dans les fonderies suédoises), élément classifié comme critique par l'Union Européenne. La fabrication de l’acier génère des quantités considérables de laitiers. Euroslags parle de 38.5 Mt pour la seule année 2022 en Europe, ce grand volume est principalement revalorisé par l’industrie dans le secteur du génie civil en tant que substituts d’agrégats ou intégré dans le ciment sans récupération de métal préalable, cependant une quantité non négligeable finit encore en décharge [3]. Ce travail présente une Analyse des Flux de Matières (MFA) réalisée dans le cadre du projet Horizon Europe FutuRaM. Elle a permis de suivre les métaux critiques dans les différents flux de laitiers, à partir de données documentées de 2010 à 2023 et projetant jusqu'en 2050, à l’échelle mésoscopique de l’Europe. A la connaissance des auteurs, très peu d'études se sont intéressées aux gisements des laitiers à cette échelle et avec comme objectif une récupération des métaux critiques. En effet, jusqu’à présent la communauté s’est concentré principalement sur la valorisation matière de ces déchets. Elle évalue trois scénarios distincts, chacun reflétant un niveau d'ambition spécifique. Le premier suppose une situation de référence de « business as usual », dans laquelle la situation actuelle est gelée et représente une moyenne des dernières années. Le second scénario a une ambition accrue sur le recyclage qui se retrouve accentuée (c’est-à-dire que la part d’aciéries électrique dans la production d’acier augmente). Le dernier scenario vise à mettre en place une économie plus circulaire provoquant une réduction de la demande qui sanctionnera la production primaire d’acier, et en conséquence, de ses laitiers. La récupération d’un métal comme le vanadium n’est pas exempte d’impact environnemental et peut aller à l’encontre d’autres solutions de valorisation déjà existantes. L'absence de données systématiques et rigoureuses limite la précision des résultats. En effet, la revue de littérature [5-12] confirme une composition des laitiers très variable, dépendante de l'origine du minerai et du procédé qui le fabrique. De plus, les technologies de récupération de métaux critiques restent peu matures, un seul projet industriel à l’étude en Finlande pour récupérer le vanadium, et sont donc sujets à une grande incertitude. Enfin, ces projets se heurtent à une difficulté supplémentaire ; trouver une viabilité économique et environnementale, tout en combinant la récupération des métaux qui de fait, représentent seulement une petite partie du volume de déchets total et laisse donc à gérer une importante quantité de déchets restants après le processus d’extraction
Revisiting artisanal and small-scale mining (ASM) – challenge or opportunity for the supply of critical raw materials?
No full textInternational audienceThe challenges and opportunities artisanal and small-scale mining (ASM) will pose for an evolving EU critical raw materials (CRM) supply-web are examined through analysis of current business models and integration strategies. ASM operations are often associated with poor operational health & safety, negative environmental impacts, and poor governance, creating tension with EU policy goals of ensuring a fair, responsible, and sustainable supply of CRM. This analysis, drawing on experience from the Horizon Europe project AfricaMaVal and an extensive literature review, examines ASM motivations, constraints, and business models. The methodology combines systematic literature analysis with practical insights from field experience to develop a typology of integration strategies. Key findings reveal that traditional formalisation approaches often fail because they misunderstand local context and power structures. Based on these findings, we propose a graduated approach to ASM integration that builds on existing structures while progressively improving environmental, social and governance (ESG) compliance. The paper presents five business model categories for sustainable integration of ASM-produced CRM into EU supply-webs, emphasising the need for economic incentives that align with local realities rather than imposing external standards
The evolution of drought characteristics in semi-arid Africa over the last four decades
No full textInternational audiencetudy regionSemi-arid Africa, covering six subregions: the Mediterranean (MED), Sahel, North Eastern Africa (NEAF), South Eastern Africa (SEAF), Southern Africa (SAF), and Madagascar (MDG).Study focusWe analyse drought duration, intensity, and severity from 1979 to 2024 across semi-arid Africa. Using Climate Prediction Center (CPC, 0.5°) precipitation and temperature, we compute the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Trends are detected with the Mann–Kendall test and Theil–Sen slope estimator. Short-term droughts (3–6 months), strongly influenced by temperature variability, are distinguished from 12-month events driven by cumulative hydrological deficits.New hydrological insightsThree drought episodes emerge: the early 1990s, early 2000s, and the recent period beginning in 2022. Long time-scale indices (SPI-12, SPEI-12) capture the most persistent droughts, whereas short time-scale indices (SPEI-3, SPEI-6) reveal intense temperature-driven episodes. In MED, only 7–25 % of grid cells show significant SPI trends in duration, severity, and intensity, but up to 75 % exhibit drought intensification with SPEI, underscoring strong temperature sensitivity. Across NEAF, SEAF, SAF, and MDG, 25–55 % of pixels show significant increases in drought duration (up to +3 months per decade), severity (+3 units per decade), and intensity (+0.5 units per decade). Parts of the western Sahel and southern Madagascar display decreasing trends. Overall, the study delivers a continent-wide assessment of drought evolution and identifies hotspots where intensifying drought threatens water resources and food security
Digitalisation in geosciences for environmental protection
No full textInternational audienceData Science (Digitalization and Artificial Intelligence) became more than an important facilitator in various domains in fundamental and applied sciences as well as industry and is disrupting the way of research already to a large extent. Originally, data sciences were viewed to be well-suited, especially, for data-intensive applications such as image processing, pattern recognition, etc. In the recent past, particularly, data-driven and physics-inspired machine learning methods have been developed to an extent that they accelerate numerical simulations and became directly applied in the nuclear waste management cycle. In addition to process-based approaches for creating surrogate models, other disciplines such as virtual reality methods and high-performance computing are leveraging the potential of data sciences more and more. The present challenge is utilizing of the best experimental and monitoring data as well as model concepts and tools to integrate multi-chemical-physical, coupled processes, multi-scale and probabilistic simulations in Digital Twins (DT) able to mirror or predict the performance of its corresponding existing or future physical implementations including workflows. The call for the Topical Collection was initiated from different actors, including research entities, technical support organizations and nuclear waste management organizations of the European projects EURAD (European Joint Programme on Radioactive Waste Management) and PREDIS (Pre-disposal Management of Radioactive Waste). The Topical Collection attracted a large number of manuscripts, more than eighty of which were published. These articles reveal a strong academic focus on using machine learning to map and assess soil and groundwater resources, hydrology and land use, landslides, and climate protection. They also highlight the core theme of nuclear waste management
Le projet de recherche S-PASS : ressources et usages du sous-sol de la métropole du Grand Paris
No full textInternational audienceFor the city, the subsoil represents fundamental challenges for its development and evolution. It is the foundation for surface developments, a place that houses public transportation and technical networks. It is also a source of geothermal energy that is still insufficiently exploited in urban areas. In the context of climate change, the effects of which will be particularly marked over the coming decades in major metropolises, the subsoil can also become a new space to be developed as an alternative to urban sprawl. The S-PASS scientific research project, part of the “Subsurface: a common good” research program funded under the France 2030 plan, is built around these issues, on the geographical perimeter of the Greater Paris metropolis. The project covers the first 200 m of the subsoil, and aims to (1) gain a better understanding of the geological formations, their associated variability, and their geomechanical properties, and to test new geophysical methods in urban areas; (2) build a 3D digital model coupling the 3D geological model of the Cenozoic geological formations, with existing underground public transport infrastructures. The merging of these two models will enable the creation of a digital twin prototype of the Parisian urban underground; (3) to place these underground spaces in the public imagination and in its perception of future developments, to analyse the environmental footprint of underground use in the urban development model in comparison with surface developments ; and finally (4) to consider innovative methodologies for increasing circular economy applications, i.e. reclaiming excavated soil from underground works and using low enthalpy geothermal solutions. This research project, with a budget of 3 million euros and a duration of 7 years, started in 2023. It brings together eleven academic and institutional partners. This article describes the stakes, content and prospects of this project.Le sous-sol représente pour la ville des enjeux fondamentaux pour son développement et son évolution. Il est à la fois le support des fondations des aménagements de surface, un lieu qui abrite les transports publics et les réseaux. Il contient également une source d'énergie géothermique encore insuffisamment exploitée en zone urbaine. Dans le contexte de changement climatique, le sous-sol peut aussi devenir un nouvel espace à développer, en alternative de l'étalement urbain. Le projet de recherche scientifique S-PASS, inscrit dans le programme de recherche PEPR « Sous-sol -Bien commun », financé dans le cadre du plan France 2030, est construit autour de ces enjeux, sur le périmètre géographique de la métropole du Grand Paris. Il s'intéresse aux premiers 200 m du sous-sol et se décline en quatre objectifs. Le premier consiste à mieux connaitre les formations géologiques, leur variabilité spatiale et leurs propriétés géomécaniques. Le second objectif vise à construire une maquette numérique 3D couplant d'une part le modèle géologique 3D des formations cénozoïques et d'autre part, les infrastructures souterraines existantes de métro, afin de créer un prototype de jumeau numérique du sous-sol parisien. Le troisième objectif est dédié à la durabilité et à la perception sociétale des villes souterraines. Il vise d'une part à replacer ces espaces souterrains dans l'imaginaire du grand public et dans sa perception des développements futurs et d'autre part à construire une méthodologie permettant une qualification environnementale objective de l'utilisation du sous-sol en comparaison d'aménagements de surface. Enfin le dernier volet, focalisé sur les ressources souterraines, vise à envisager des méthodologies innovantes pour la valorisation des terres excavées, et à étudier la géothermie de proche surface. Ce projet de recherche, doté d'un budget de 3 millions d'euros pour une durée de 7 ans, a démarré en 2023. Il réunit onze partenaires académiques et institutionnels. Cet article détaille les enjeux, le programme et les perspectives du projet
Spectral induced polarization monitoring of toluene biodegradation by Rhodococcus wratislaviensis in controlled laboratory conditions
No full textInternational audienceThe global prevalence of organic pollutants presents a significant environmental challenge, necessitating sustainable remediation strategies. In situ biodegradation emerges as a cost-effective and eco-friendly solution. However, the real-time monitoring of in situ bacterial activities, particularly biodegradation processes, remains a challenge due to the limitations of traditional intrusive methods, including issues of representativeness, reproducibility and high-associated costs. Spectral induced polarization (SIP) has shown sensitivity to surface changes in subsurface environments, especially for biogeochemical reactivity monitoring including those associated with biodegradation. Despite this potential, advances have to be made to quantitatively link SIP parameters to in situ biodegradation processes. This study addresses this gap by conducting controlled biogeophysical experiments on a sand-packed column undergoing biodegradation facilitated by Rhodococcus wratislaviensis IFP 2006. SIP measurements were paired with bacterial growth kinetics to develop a quantitative model estimating bacterial growth. The results demonstrate that SIP, coupled with routine laboratory measurements, can effectively and quantitatively assess bacterial growth and the biodegradation of organic pollutants. These findings highlight the potential of SIP as a non-intrusive and reliable method for monitoring biodegradation in contaminated subsurface environments