Search Results (252)

The aspiring United Nations Educational, Scientific and Cultural Organization (UNESCO) Global Geopark of Chefchaouen includes part of the Talassemtane National Park (TNP), classified by UNESCO as an exceptional natural heritage site within the Intercontinental Mediterranean Biosphere Reserve (RBIM). The other section corresponds to the Ghomara Coast (GC), characterized by an outstanding succession of metamorphic rocks. This study identifies and highlights the most significant sites of geological interest (geosites and geodiversity sites) in the territory. Forty-two sites are proposed as geological heritage sites, thirty of which are organized into four accessible georoutes (Oued Laou Valley, Ghomara Coast, Talambote–Akchour, and Chaouen–Ametrasse), while the other twelve are located along trails and forest tracks inside or near the TNP. These sites cover a wide range of geological typologies, including structural geology, stratigraphy–sedimentology, paleontology, geomaterials, petrology, geomorphology, and hydrogeology. To classify and rank the sites objectively, a numerical methodology based on the recent literature was applied. Scientific value (SV), Potential Educational Use (PEU), and Potential Touristic Use (PTU) were quantified using multiple criteria, facilitating route selection according to user needs. Degradation Risk (DR) was also measured, providing managers with essential guidance for an appropriate geoconservation plan. Actions consistent with UNESCO Global Geoparks Network criteria are proposed to improve conservation, support education, and promote sustainable tourism, thereby enhancing economic activity in the region. The initiative aims to promote the region’s exceptional geological, cultural, and natural heritage. The Chefchaouen Geopark was designated a deferred candidate during the UNESCO Global Geoparks Council meeting of 8–9 September 2024. According to Section 5.5 of its guidelines, the Council may defer an application for up to two years to allow improvements without requiring a second field evaluation. To consolidate the Chefchaouen candidacy, we developed a strategy to strengthen compliance with UNESCO requirements, reduce the risk of final rejection, and maintain the territory’s credibility with international networks and partners. This work presents an operational, costed, and scheduled roadmap enabling stakeholders at all levels to converge toward a complete and coherent application. Full article

To address the challenges of water hazard control in the thick water-rich sandstone aquifer of the roof under monoclinal structure conditions at Panel 110504 of Wangwa Coal Mine, as well as the problems of excessive ineffective drainage and high cost associated with the traditional full-face pre-drainage method, a study on the coordinated technology of mining progress and roof water drainage was carried out. By analyzing the geological and hydrogeological conditions of the panel, it was determined that the height of the water-conducting fracture zone reaches 228 m, which has penetrated the Yan’an Formation and entered the sandstone aquifer of the Zhiluo Formation, forming a unified composite water-filling source from the two aquifers. Based on calculations using the Theis equation and field drainage tests, the stable drainage time was determined to be 95 d and the advance drainage distance 300 m. Accordingly, a coordinated technical scheme of “sectional drainage while mining” was proposed, optimizing the layout parameters of drainage boreholes and the division of drainage sections. Field application results show that this technology reduced the average water inflow of the panel by 255.94 m³/h compared with the traditional mode, cumulatively saved 5.1413 million m³ of drainage water, cut drainage costs by 20.5652 million CNY, and no water hazard occurred. The research results can provide a technical reference for mining coal seams with water-rich roof under similar monoclinal structure conditions. Full article

Natural gas represents a pivotal transitional clean energy resource, and biogenic coalbed methane (CBM) is ubiquitously distributed in coal reservoirs worldwide. In the context of carbon neutrality targets and the growing demand for large-scale commercial CBM exploitation, innovative technological solutions are urgently required. CBM bioengineering aims to substantially enhance CBM production by stimulating biomethane generation, promoting gas desorption, and improving reservoir permeability, while simultaneously enabling effective CO₂ sequestration. The potential for biomethane generation is largely governed by the intrinsic physicochemical characteristics of coal, including aromatic structures, maceral composition, and pore–fracture architecture. In addition, hydrogeological conditions—such as geothermal gradients, pH variability, and redox potential—play critical roles in regulating microbial functional gene expression and metabolic enzyme synthesis. Core pretreatment strategies in coalbed gas bioengineering can be broadly classified into approaches that enhance coal bioconversion potential and those that optimize functional microbial consortia. Electric fields and conductive materials can influence microbial community structure by enriching electroactive microorganisms and facilitating interspecies electron transfer. In addition to engineered conductive interventions, reservoir environmental conditions also play an important role in shaping methanogenic community structure. Experimental observations under reservoir-relevant CO₂ pressure and temperature conditions indicate that deep coalbed environments are associated with shifts in methanogenic community composition, including an increased relative abundance of hydrogenotrophic methanogens. These observations suggest that physicochemical conditions in deep coal seams may favor hydrogen-dependent CO₂ reduction pathways, thereby supporting hydrogenotrophic methanogenesis and contributing to biomethane generation. The integration of supercritical CO₂ with microbially acclimated stimulation fluids as an innovative reservoir fracturing strategy offers multiple advantages, including effective reservoir stimulation, permanent carbon sequestration, and sustainable biomethane generation. Future research should focus on modulating coal matrix bioavailability, optimizing microbial consortia, enhancing interspecies metabolic synergies, and advancing carbon fixation bioprocesses to facilitate the large-scale implementation of coalbed gas bioengineering systems. This review synthesizes recent advances in microbially mediated CBM enhancement and CO₂ sequestration, with a particular focus on field-scale evidence and the key challenges that must be addressed for large-scale implementation. Full article

Accurate prediction of aquifer water abundance is critical for coal mine safety, yet traditional static models often fail to capture the spatial heterogeneity and non-stationarity of hydrogeological conditions. This study proposes a dynamic evaluation methodology integrating Grey Relational Analysis, the Analytic Hierarchy Process, and a Time-Varying Parameter Cubature Kalman Filter (TVP-CKF). By reconceptualizing spatial borehole data as a dynamic time-series process, the model recursively updates the contribution weights of six controlling factors based on monitoring data from 2012 to 2020. Analysis reveals a structural shift in the groundwater system: the influence of hydrochemical factors (TDS) has diminished, while hydraulic conductivity has become the dominant control over time. The TVP-CKF model significantly outperformed static regression and recursive least squares baselines, demonstrating superior convergence stability and precisely capturing transient inflow fluctuations. Furthermore, its uncertainty quantification effectively bounded extreme low-flow events within 95% confidence intervals. This approach validates the necessity of adaptive modeling in evolving geological environments, providing a robust, risk-quantified tool for precise water inrush prevention. Full article

Post-disaster reconstruction requires instruments capable of ensuring procedural consistency, administrative transparency, and the systematic integration of geohazards, all of which are essential for safeguarding communities. This study presents the digital platform established under Italian Law 55/2019 for the reconstruction of the areas on Mt. Etna affected by the Mw 4.9 earthquake of 26 December 2018, emphasizing its innovative contribution to current international approaches to reconstruction governance. The platform standardizes the entire administrative workflow and is centered on the Parametric Form, which enables an objective calculation of eligible reconstruction grants based on damage indicators, vulnerability metrics, and parametric cost functions. A defining feature of the Etna model is the structural integration between administrative procedures and geohazard mitigation, achieved through updated hazard maps and protocols that incorporate geological, hydrogeological, and geomorphological conditions. This approach reframes reconstruction as an opportunity to reduce overall territorial vulnerability. The system also includes public monitoring tools (WebGIS and dashboards) that enhance traceability, compliance, and stakeholder engagement. Expected outcomes include shorter administrative timelines, improved interinstitutional coordination, and the potential transferability of the model to other emergency contexts. In comparison with international cases, the Etna experience represents an original integration of digitalization, parametric assessment, and site-specific hazard mitigation. Full article

The southeastern Iberian Peninsula, particularly the Águilas Arc within the Neogene Volcanic Province (NVP), represents a promising geothermal domain with complex tectonics and geology. The Palomares Fault Zone (PFZ), a key shear structure initiated during the Late Miocene, acts as a conduit for fluid migration, promoting mineralization and potential anomalies of rare and critical metals through fluid–rock interaction. This study investigates such interactions in the southernmost Águilas Arc, focusing on the El Arteal fault segment within the eastern PFZ strand. Mineralogical, geochemical, and hydrogeological analyses were performed using XRD, SEM, and ICP-MS techniques. Results reveal six mineral assemblages (MA) within the fault segment where the fault gouge samples were characterized by cataclastic textures and the occurrence of authigenic minerals, including halite, kaolinite, illite, paragonite, goethite, hematite, gypsum, barite, celestine, and quartz. Geochemical data indicate enrichment signatures in large-ion lithophile elements (LILE) and minor chalcophile and light rare-earth elements (LREE). Two thermal hydrofacies with alkaline metals enrichment were identified in wells and mine shafts: (1) Na⁺SO₄²⁻ and (2) Na⁺Cl⁻, where the latter exhibits high Na⁺ and Cl⁻ concentrations toward deeper sectors. These findings suggest multiple stages of fluid–rock interaction controlled by temperature: an early phase dominated by epithermal mineralization, followed by late-stage circulation of hypersaline fluids. This evolution provides an abnormal geochemical signature that is unique in the Aguilas Arc Geothermal System. Full article

Geodiversity assessment has become an important tool for understanding the spatial heterogeneity of abiotic elements and supporting conservation and land-use planning in protected areas. This study presents a comprehensive geodiversity assessment of the Mount Cangshan Global Geopark in Dali, Yunnan Province, China. The primary objective was to develop a quantitative geodiversity evaluation model based on spatial density metrics, addressing existing gaps in subjective and non-reproducible assessment methods. The study integrates four key dimensions of geodiversity: geological units, structural geomorphology, hydrogeology, and soils and land cover. By employing a hybrid AHP-CRITIC method to assign both subjective and objective weights to indicators, the study computes the Geodiversity Index (GDI) to quantify and map geodiversity across the geopark. Results show significant spatial heterogeneity, with high-geodiversity areas concentrated in the central and northern regions, primarily driven by tectonic and geological complexity and glacial, fluvial, and hydrological processes. The results indicate that the GDI can be used as a reliable tool for geosite delineation, heritage management, and sustainable tourism development. The findings provide a framework for geodiversity assessment and support landscape-level land-use zoning, conservation prioritization and sustainable land management in mountain geoparks. Full article

Groundwater, a critical resource for regional water security and public health, faces escalating threats from heavy metal contamination—a pressing environmental challenge worldwide. This study focuses on the central-south Hunan region of China, a mineral-rich, densely populated area characterized predominantly by non-point-source pollution, aiming to systematically unravel the spatial patterns, source contributions, and associated health risks of heavy metals in local groundwater. Based on 717 spring and well water samples collected in 2024, we determined pH and seven heavy metals (As, Cd, Pb, Zn, Fe, Mn, and Tl). By integrating hydrogeological zoning, lithology, topography, and river networks, the study area was divided into 11 assessment units, clearly revealing the spatial heterogeneity of heavy metals. The results demonstrate that exceedances of Cd, Pb, and Zn were sporadic and point-source-influenced, whereas As, Fe, Mn, and Tl showed regional exceedance patterns (e.g., Mn exceeded the standard in 9.76% of samples), identifying them as priority control elements. The spatial distribution of heavy metals was governed the synergistic effects of lithology, water–rock interactions, and hydrological structure, showing a distinct “acidic in the northeast, alkaline in the southwest” pH gradient. Combined application of the APCS-MLR and PMF models resolved five principal pollution sources: an acid-reducing-environment-driven release source (contributing 76.1% of Fe and 58.3% of Pb); a geogenic–anthropogenic composite source (contributing 81.0% of Tl and 62.4% of Cd); a human-perturbation-triggered natural Mn release source (contributing 94.8% of Mn); an agricultural-activity-related input source (contributing 60.1% of Zn); and a primary geological source (contributing 89.9% of As). Monte Carlo simulation-based health risk assessment indicated that the average hazard index (HI) and total carcinogenic risk (TCR) for all heavy metals were below acceptable thresholds, suggesting generally manageable risk. However, As was the dominant contributor to both non-carcinogenic and carcinogenic risks, with its carcinogenic risk exceeding the threshold in up to 3.84% of the simulated adult exposures under extreme scenarios. Sensitivity analysis identified exposure duration (ED) as the most influential parameter governing risk outcomes. In conclusion, we recommend implementing spatially differentiated management strategies: prioritizing As control in red-bed and granite–metamorphic zones; enhancing Tl monitoring in the northern and northeastern granite-rich areas, particularly downstream of the Mishui River; and regulating land use in brick-factory-dense riparian zones to mitigate disturbance-induced Mn release—for instance, through the enforcement of setback requirements and targeted groundwater monitoring programs. This study provides a scientific foundation for the sustainable management and safety assurance of groundwater resources in regions with similar geological and anthropogenic settings. Full article

Geological storage of carbon dioxide in faulted sedimentary basins requires suitability evaluation methods that can address uncertainty, indicator interaction, and limited data availability. This study develops an integrated evaluation framework that combines the Analytic Hierarchy Process, triangular fuzzy numbers, and the Choquet fuzzy integral to assess basin-scale geological carbon dioxide storage suitability. The framework enables structured weight determination, explicit representation of expert uncertainty, and non-additive aggregation of interacting indicators. The evaluation focuses on deep saline aquifers in the Jianghan Basin and is based on seventeen indicators covering geological, structural, hydrogeological, and socio-economic conditions. The assessment integrates seismic interpretation, geological mapping, logging data, and published datasets, and is conducted at the level of tectonic units to support basin-scale screening. The method is applied to the Jianghan Basin using seventeen geological, structural, hydrogeological, and socio-economic indicators. The results indicate that burial depth primarily acts as a threshold condition, whereas caprock sealing capacity, fault system development, and hydrogeological stability dominate suitability differentiation. Interaction analysis reveals pronounced substitution effects among geological indicators, indicating that strong performance in key safety-related factors can compensate for less favorable secondary constraints during early-stage screening. The Qianjiang Sag and Jiangling Sag are identified as the most suitable storage units. The proposed framework provides a transparent and robust tool for basin-scale screening in structurally complex, data-limited sedimentary basins. Full article

The performance degradation of concrete structures in underground water sumps within the Ordos mining area has become increasingly prominent due to environmental factors, particularly the sulfate-induced dry–wet cycles. These conditions lead to the development of cracks, spalling, and structural instability, which poses significant safety risks. This issue must be addressed with consideration of the regional hydrogeological characteristics and the current requirements for safe, sustainable, and environmentally responsible coal mining practices. The study investigates the concrete employed in the underground central water reservoir of Bulianta Coal Mine in the Ordos mining area. A novel approach is proposed for developing sulfate-resistant concrete capable of withstanding dry–wet cyclic conditions in underground environments through the utilization of coal gangue sourced from the same mining operation. Considering concrete performance, cost-effectiveness, and coal gangue utilization, a laboratory mix optimization study was conducted and the optimal mixture proportion was determined to be a 60% gangue content, a 30% fly ash content, a water–binder ratio of 0.38, which produced concrete with a compressive strength of 31 MPa. Sulfate resistance tests were conducted on the optimal mixture of dry–wet cycle-resistant concrete. The effect of different dry–wet cycle counts on the compressive strength of the coal gangue concrete was investigated, and the evolution patterns of the ascending segment shape coefficient a and descending segment shape coefficient b under sulfate-induced dry–wet cycling were analyzed. Combining the Guo Zhenhai concrete constitutive model, a concrete constitutive model suitable for the dry–wet cycle conditions of sulfate was established. Based on the proposed constitutive model, the uniaxial compressive mechanical behavior of coal gangue concrete subjected to sulfate attack was investigated through numerical simulations using the Abaqus (2020) software. The simulation results are basically consistent with the laboratory results, which proves the applicability of the constitutive model and confirms the performance of the optimal proportioning scheme for preparing sulfate-resistant dry–wet cycle concrete using coal gangue from underground mines. This study provides a new type of concrete for similar underground conditions in this mining area and offers a new approach for the comprehensive utilization of coal gangue. Full article

With the continuous growth of the global population, cities worldwide face the challenge of limited surface land area, making the utilization of underground space increasingly important. The structural stability of underground tunnels is a critical component of underground space safety, influenced by the distribution of the surrounding composite strata and hydrogeological environment. To better analyze the structural stability of underground tunnels, this study proposes a method for estimating the distribution of composite strata that considers the surrounding hydrogeological conditions. The method uses a hydrogeological analysis of the tunnel area to determine the spatial estimation range and unit scale to meet the actual project requirements and then uses the geostatistical kriging method to obtain a distance-weighted interpolation algorithm for the impact area. First, the spatial data are used to obtain the statistical characteristics. Second, the statistical data are interpolated, multifractal theory is used to compensate for the kriging method of sliding weighted average defects, and the local singularity of the regionalized variables is measured. Finally, the mean results of 100 simulations are compared with the empirical results for the tunnel. The interpolation results reveal that this method can be used to quickly obtain good interpolation results. Full article

This paper introduces MC-former, a Transformer-based rainfall-runoff model designed for hourly regional runoff prediction. Unlike the original Transformer, MC-former integrates a water-balance-guided constraint into the attention layer and enforces physical consistency through a penalty structure. Additionally, MC-former transforms the aggregated input embeddings into the frequency domain via a Fourier transform, enabling more effective modeling of long-range dependencies in hourly runoff data. We tested MC-former on two tasks: regional rainfall-runoff simulation and runoff prediction for ungauged basins with similar hydrogeological units. In the first task, MC-former outperformed baseline models in prediction accuracy. In the second, it improved performance under ungauged conditions, with a notable increase in the Nash–Sutcliffe efficiency coefficient (NSE) in the HUC03 region, surpassing the baseline by nearly 0.08. Furthermore, adopting a strategy of training MC-former with hydrological data from climatically and geologically similar regions further enhanced its predictive accuracy, as demonstrated by consistently higher NSE and Pearson-r values. The MC-former model can support sustainable water resources management and enable transferable prediction of rainfall runoff in ungauged basins. Full article

This study investigates the coupled relationship between groundwater chemistry, lithology, and structural features in the dry zone of Netiyagama, Sri Lanka, within a fractured crystalline basement. Groundwater chemistry fundamentally reflects geological conditions determined by rock-water interactions, we hypothesized that the specific spatial patterns of groundwater chemistry in heterogeneous fractured systems are distinctly controlled by integrated effects of lithological variations, structurally driven flow pathways, aquifer stratification, and geochemical processes, including cation exchange and mineral-specific weathering. To test this, we integrated hydrogeochemical signatures with mapped hydrogeological data and applied multi-stage multivariate analyses, including Piper diagrams, Hierarchical Cluster Analysis (HCA), and Principal Component Analysis (PCA), and various bivariate plots. Piper diagrams identified five distinct hydrochemical facies, but these did not correlate directly with specific rock types, highlighting the limitations of traditional methods in heterogeneous settings. Employing a multi-stage multivariate analysis, we identified seven clusters (C1–C7) that exhibited unique spatial distributions across different rock types and provided a more refined classification of groundwater chemistries. These clusters align with a three-unit aquifer framework (shallow weathered zone, intermittent fracture zone at ~80–100 m MSL, and deeper persistent fractures) controlled by a regional syncline and lineaments. Further analysis through bivariate diagrams revealed insights into dominant weathering processes, cation-exchange mechanisms, and groundwater residence times across the identified clusters. Recharge-type clusters (C1, C2, C5) reflect plagioclase-dominated weathering and short flow paths; transitional clusters (C3, C7) show mixed sources and increasing exchange; evolved clusters (C4, C6) exhibit higher mineralization and longer residence. Overall, the integrated workflow (facies plots + PCA/HCA + bivariate/process diagrams) constrains aquifer dynamics, recharge pathways, and flow-path evolution without additional drilling, and provides practical guidance for well siting and treatment. Full article

The observed shortage of water resources in the western and southern regions of the Russian Federation may soon affect the territory of the Republic of Bashkortostan. An increase in the share of groundwaters can help to solve this problem. To provide the population of the republic with water resources, the groundwater of magnesium–bicarbonate-type from the Kraka ophiolite massifs can be used. The massifs occur on the western slope of the Southers Urals. In this work we studied ultramafic rocks and their influence on the formation of the chemical composition of water. The research area is located in the northern part of the Zilair synclinorium, which occurs within the Central Ural megazone. In terms of hydrogeology, of particular importance to the territory of the synclinorium is the Zilair basin of fracture waters of the second order, which is part of the Uralian hydrogeologic folded zone. The ultramafic rocks from the studied area have consistently high CaO/Al₂O₃ ratios (0.4–1.6), which indicates the widespread development of parageneses with participation of clinopyroxene and a low degree of depletion of the primitive mantle source. Because of the complex geological structure of the area, water samples collected from both water points in the Kraka massifs, and the surrounding Early–Middle Paleozoic rocks were analyzed for major ions using a laboratory method to identify possible hydro-geochemical zoning. A statistical analysis was then conducted based on the obtained anion–cation composition data. From the viewpoint of the hydrolytic concept, the formation of the chemical composition of groundwater takes place due to the removal of Mg²⁺ from the rock-forming minerals of ultramafic rocks (olivine and pyroxene) and the supply of Na⁺, K⁺, Ca²⁺, and SO₄²⁻ Cl⁻ from atmospheric precipitations. The bicarbonate anion has a complex nature, where both biochemical processes in the soil and atmospheric precipitation play a significant role. Magnesium–bicarbonate-type of waters, due to low mineralization (to 1 g/L) and the majority of other geochemical parameters (pH of the medium, and content of Na, K, Ca, SO₄, and Cl), whose values that are within the limits set by the World Health Organization (WHO), can be used as drinking water. The increased values of total hardness (0.20–3.39 mmol/L) in accordance with the regulatory document SanPiN 1.2.3685–21, adopted by the Russian Federation, do not exceed the maximum permissible concentrations (up to 7.00 (10.00) mEq/L or 3.50 (5.00) mmol/L). The high magnesium content, in accordance with GOST (state standard) R 54316–2020, allows the magnesium–bicarbonate waters of the Kraka massifs to be classified as table mineral waters for the treatment of various diseases (including hypomagnesemia). Full article