Search Results (5,869)

As global climate change intensifies, hydrological processes in arid inland river basins are undergoing profound transformations, posing severe challenges to regional water security and ecological stability. This study aims to develop a coupled SWAT-LSTM model integrating glacier melt processes to simulate runoff dynamics in the Keria River basin under climate change, providing a basis for local water resource management. Based on natural monthly runoff observations from the Langgan hydrological station (1961–2015), glacier data extracted from Landsat 8 remote sensing imagery (2013–2019), and downscaled data from the CMIP6 Multi-Model Ensemble (MME), this study constructed a SWAT-LSTM coupled model to simulate future scenarios (2026–2100). Research indicates that this hybrid model significantly enhances the accuracy of hydrological simulations in high-altitude glacier-fed catchments. The Nash efficiency coefficient (NSE) during the validation period reached 0.847, representing a 15% improvement over the SWAT model. SSP5-8.5 is identified as a high-risk scenario, underscoring the urgency of emissions reduction; SSP1-2.6 represents the most desirable pathway, with its relatively stable pattern offering sustained advantages for long-term water resource management in the basin. The study further reveals a negative feedback mechanism between glacier ablation and runoff increase, validating the regulatory role of Jiyin Reservoir’s “store during floods to compensate for droughts” operation strategy in balancing basin water resources. This study explores the coupling path between the physical model and the deep learning model, and provides an effective integration scheme for the hydrological simulation of the global watershed with ice–snow meltwater as the main recharge runoff, especially for the adaptive management of water resources in inland river basins in arid areas. Full article

This study investigates the mechanisms behind strong water sensitivity in some low-clay-mineral-content tight conglomerate reservoirs in China’s Mahu Sag. Using core-scale water sensitivity tests, mineral analysis, in situ micro-CT scanning, and digital core techniques, we analyzed how water sensitivity alters pore structures across cores of varying permeability. Key findings include the following: (1) Water sensitivity damage increases as initial gas permeability decreases. (2) Despite low clay content, significant water sensitivity arises from the combined effect of water and velocity sensitivity, driven mainly by illite and kaolinite concentrated in gravel-edge fractures and key flow channels. (3) Water sensitivity causes non-uniform pore structure changes—some macropores and throats enlarge locally, reflecting heterogeneity. (4) Structural responses differ by permeability: medium–low permeability cores suffer from clay mineral swelling and particle migration, whereas high-permeability cores resist overall damage and may even have main flow paths enhanced by flushing. (5) Water sensitivity mainly degrades smaller pores but can improve larger ones, with the critical pore-size threshold between macro- and micro-pores inversely related to permeability. This work clarifies the pore-scale mechanisms of water sensitivity in some low-clay-mineral-content tight conglomerates, and can provide guidance for the optimization of water types injected into similar conglomerate reservoirs. Full article

Low-lying coastal plains are increasingly threatened by saltwater intrusion, yet the extent of the phenomenon and the role of coastal dune systems remain unevenly assessed. In the northern Adriatic Sea (NE Italy), salinisation has been documented, but systematic, spatially resolved studies are lacking. This work investigates the Belvedere–San Marco relict dune system to assess its hydrogeological function and vulnerability to seawater intrusion. An integrated methodology combining borehole and core stratigraphy, in situ water electrical conductivity (EC) measurements, and multi-method geophysical surveys (FDEM, ERT, GPR, active seismics) was tested. Results reveal a consistent stratigraphy of permeable aeolian sands overlying clay-rich units, with groundwater EC values in the dune sector always remaining well below thresholds for brackish or saline conditions. Geophysical imaging reveals that the dunes are low-conductive bodies contrasting sharply with the conductive surrounding lowlands, thus indicating the persistence of a freshwater lens sustained by local recharge within the dunes. The Belvedere–San Marco dunes therefore act as both freshwater reservoirs and natural hydraulic barriers, buffering shallow aquifers against salinisation. This study demonstrated the applicability of integrated geophysical methods to extensively investigate shallow phreatic aquifers lying a few metres below the surface, and establishes a baseline for monitoring future changes under rising sea levels, subsidence, and increased groundwater exploitation. Full article

Diagnosing water-phase damage remains challenging because routine petrophysical parameters do not capture capillary hysteresis and pressure-transmission effects. In this study, a standardized, auditable workflow was established to link laboratory descriptors to field-relevant cleanup. Full-curve mercury injection capillary pressure data were acquired and converted using consistent Washburn parameters, from which withdrawal efficiency was computed on the withdrawal branch. A pressure-transmission coefficient was evaluated under unified boundary conditions to complement permeability and porosity. After preprocessing and partial least-squares regression (PLSR) screening, MICP descriptors were clustered by k-means (k = 5) to obtain reservoir Types I–V. Regressions relating WE to permeability and flowback behavior were then used to assess engineering relevance. The results indicate that WE capture hysteretic trapping/back-pressure not contained in permeability or porosity and, when interpreted jointly with PTC, differentiates reservoir types by cleanup propensity. This framework provides a reproducible bridge from laboratory MICP hysteresis to field-scale flowback interpretation. Practical implications include prioritization of gas–wet wettability modification, low-surface-tension systems, and minimized early liquid loading for clusters exhibiting higher WE and lower PTC. Full article

Serpentinite soils represent extreme environments characterized by deficiencies in essential nutrients (Ca, K, P, N), an unfavorable Ca/Mg ratio, low water retention, and elevated concentrations of several geogenic potentially toxic elements (PTEs). In particular, the study site, located in Sassello (Liguria, Italy) within the serpentinites of the High-Pressure–Low-Temperature (HP–LT) metaophiolites of the Voltri Massif, exhibited concentrations of chromium, nickel and cobalt exceeding Italian legal thresholds by up to one order of magnitude. This study aimed to assess fungal diversity and to isolate culturable strains naturally adapted to these challenging conditions for potential use in bioremediation. Culturable-dependent analyses allowed for the isolation of viable fungal strains, with Penicillium (52%), Umbelopsis (17.9%), and Aspergillus (11.6%) found as dominant genera. Additionally, metabarcoding analyses provided a broader view of fungal community composition, revealing the presence and distribution of both culturable and non-culturable taxa. The combined approach highlighted the richness of the serpentinite soil mycobiota and its role as a reservoir of PTE-resistant organisms. These findings offer new insights into the ecology of metal-rich soils and identify promising candidates for sustainable remediation strategies in PTE-contaminated environments. Full article

Deeply buried carbonate successions in China’s Tarim Basin host substantial hydrocarbons. In the southern Tahe Oilfield, Middle–Lower Ordovician limestones show little evidence of subaerial weathering because the Upper Ordovician strata protected them; nevertheless, the genesis and evolution of these carbonate reservoirs remain debated. Using cores, conventional and image logs, 3D seismic interpretation, and geochemical data, this study characterizes Paleozoic faulting and diagenetic fluids in the area. Four principal fluid types are identified—meteoric water, formation water, hydrothermal fluids, and mixed fluids. Two episodes of NNW- and NNE-trending strike-slip faulting during the Middle Caledonian and Early Hercynian periods facilitated fluid migration and dissolution. Later, Late Hercynian faults acted as primary pathways for hydrothermal flow, promoting the development of hydrothermal dissolution pores and caverns. The work clarifies how the interplay between strike-slip faulting and distinct diagenetic fluids governs reservoir development, providing theoretical guidance for predicting deep carbonate reservoirs and for hydrocarbon exploration and production. Full article

Identifying the key drivers behind the spatiotemporal dynamics of ecosystem service functions is essential for clarifying how ecosystems respond to environmental changes. Such insights deepen our understanding of the evolution of complex ecological processes and service functions, and provide critical references for ecological governance, policy-making, and the pursuit of high-quality development pathways. In this study, the Remote Sensing Ecological Index (RSEI) was first constructed for the upstream basin of the Danjiangkou Reservoir using satellite imagery (2015 and 2024). We then employed the InVEST model to quantify six ecosystem service functions and their corresponding services: water purification (total nitrogen and total phosphorus), soil retention (soil erosion), water yield, carbon storage, and habitat provision (habitat quality). Finally, this study analyzes the driving mechanisms as well as the coupling coordination degree between the RSEI and six ecosystem service functions. From 2015 to 2024, the area classified as “excellent” in RSEI significantly expanded from 263.34 km² (3.22%) to 2566.21 km² (31.38%), reflecting a substantial enhancement in ecological quality throughout the upstream basin. There is no serious imbalance in the coupling and coordination relationship between RSEI and the value of various ecosystem service functions. Although improvements in ecosystem quality generally enhanced overall ecosystem service functions, competition among certain services was still evident in localized areas. Future ecological management should, therefore, prioritize not only the protection of ecosystem quality but also the scientific allocation of service supply and demand, the optimization of human–land relationships, and the promotion of a virtuous ecosystem cycle. Full article

Landslide disasters pose severe threats to mountainous regions, where accurate monitoring and scientific prediction are crucial for early warning and risk mitigation. This study addresses this challenge by focusing on the Outang Landslide, a representative large-scale bank slope in the Three Gorges Reservoir area known for its significant deformation responses to rainfall and reservoir-level fluctuations. The landslide’s behavior, characterized by notable hysteresis and nonlinear trends, poses a significant challenge to accurate prediction. To address this, we derived high-precision time-series deformation data by applying atmosphere-corrected Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) to Sentinel-1A imagery, with validation from GNSS measurements. A systematic analysis was then conducted to uncover the correlation, hysteresis, and spatial heterogeneity between landslide deformation and key influencing variables (rainfall, water level, temperature). Furthermore, we proposed a Spatio-Temporal Enhanced Convolutional Neural Network (STE-CNN), which innovatively converts influencing variables into grayscale images to enhance spatial feature extraction, thereby improving prediction accuracy. The results indicate that: (1) From June 2022 to March 2024, the landslide showed an overall downward displacement trend, with maximum settlement and uplift rates of −49.34 mm/a and 21.77 mm/a, respectively; (2) Deformation exhibited significant correlation, hysteresis, and spatial variability with environmental factors, with dominant variables shifting across seasons—leading to intensified movement in flood seasons and relative stability in dry seasons; (3) The improved STE-CNN outperforms typical prediction models in forecasting landslide deformation.This study presents an integrated methodology that combines InSAR monitoring, multi-factor mechanistic analysis, and deep learning, offering a reliable solution for landslide early warning and risk management. Full article

Enterocytozoon bieneusi is the most frequently diagnosed microsporidian parasite in humans and a recognized cause of diarrheal disease, particularly in immunocompromised individuals. Its broad host range, which includes livestock, companion animals, and wildlife, highlights its zoonotic potential and warrants careful epidemiological assessment. This narrative review synthesizes available data on the occurrence and genetic diversity of E. bieneusi in European domestic ungulates (cattle, pigs, sheep, goats, horses, and water buffaloes) and pets (dogs and cats), aiming to provide an integrated perspective on animal reservoirs and their relevance for public health. Publications retrieved from the Web of Science Core Collection database were systematically screened, and country-specific results were extracted, emphasizing prevalence rates, genotype distributions, and zoonotic implications. Across Europe, cattle and pigs emerged as the most studied hosts, frequently harboring zoonotic group 1 genotypes such as I, J, BEB4, BEB6, and EbpA, while small ruminants, horses, and buffaloes remain comparatively undocumented. In pets, the dog-adapted genotype PtEb IX was predominant, but several zoonotic genotypes were also identified. Overall, the current evidence confirms the wide host range of E. bieneusi in Europe but also reveals significant data gaps compared to regions such as China, underlining the need for broader surveillance and harmonized molecular approaches within a One Health framework. Full article

Low-permeability sandstone oil reservoirs, as an important type of oil and gas resource, feature high reservoir density and low permeability. The utilization of pore throats of different scales during their development process is crucial for enhancing oil recovery. Based on nuclear magnetic resonance and CT scanning techniques, this paper systematically studies the utilization limits and energy contribution of pore larynx under different displacement methods. The results show that during the water injection development process, the main pore–throat radius used by water flooding is between 1 and 20 μm. Among them, the contribution of the small pore tends to stabilize after the pressure rises to a certain stage, the contribution of the medium pore increases with the rise in pressure, while the contribution of the large pore gradually decreases with the increase in pressure. After switching to CO₂ gas flooding, the application range of the pore throat was further expanded to a smaller scale. The contribution of the small pore and the middle pore significantly increased in a specific pressure range, while the large pore made a greater contribution at a lower pressure. This paper has certain reference significance for the study of the limit and contribution of pore–throat exploitation in low-permeability sandstone oil reservoirs. Full article

Floods, especially in urbanised areas, incur enormous economic and social losses. The structural flood management is often limited by urbanization and environmental issues. Following the catastrophic flood events of 1997 and 2010, a relatively large dry polder was constructed in Racibórz Dolny, Poland, with the highest flood retention capacity in Central Europe. During the 2024 flood in Czechia and Poland, the polder was filled to 80%, which significantly reduced the floodwave crest on the Odra River (by 1.65 m), halved the peak discharge, and delayed the floodwave passage by two days according to hydrological calculations. The operation of the polder enables multifunctional use of the river valley—ranging from agriculture and mineral extraction to environmental protection—without the need for permanent water impoundment. Aggregate extraction carried out within the basin contributed to shaping the reservoir, reducing the demand for transport and construction materials, while the overburden was reused for engineering and reclamation purposes. Mining activities between 2007 and 2023 increased the retention capacity of the polder by 13%, providing an example of rational environmental resource management combined with effective flood protection. The findings demonstrate that integrating retention functions with mineral resource management represents an efficient and sustainable approach to mitigating flood impacts in large European river valleys. Full article

The Muji Fault Zone (MJF) in the northeastern Pamir Plateau hosts a well-developed non-volcanic geothermal system, characterized by widespread hot springs and mud volcanoes—where core processes of geothermal fluids, including atmospheric precipitation recharge, shallow crustal circulation, carbonate-driven water–rock interactions, and CO₂-rich fluid discharge, are tightly coupled with regional intense crustal deformation and frequent seismic activity. We collected and analyzed 22 geothermal water samples and 8 bubbling gas samples from the MJF periphery, finding that the geothermal waters are predominantly of the HCO₃-Ca·Mg hydrochemical type, with hydrogen (δD: −103.82‰ to −70.21‰) and oxygen (δ¹⁸O: −14.89‰ to −10.10‰) isotopes indicating atmospheric precipitation as the main recharge source. The Na-K-Mg ternary diagram classified the waters as immature, reflecting low-temperature water–rock interactions in the shallow crust (<3 km), while noble gas isotopes (³He/⁴He: 0.03–0.09 Ra, Ra = 1.43 × 10⁻⁶) and carbon isotopes (δ¹³C-CO₂) confirmed fluid origin from crustal carbonate dissolution; SiO₂ geothermometry estimated thermal reservoir temperatures at 67–155 °C. Long-term monitoring (May 2019–April 2024) of Tahman (THM) and Bulake (BLK) springs revealed significant pre-seismic anomalies: before the 2023 Tajikistan Ms7.2 and 2024 Wushi Ms7.1 earthquakes, Na⁺, Cl⁻, and SO₄²⁻ concentrations showed notable negative anomalies (exceeding 2σ of background values) with synchronous trends between the two springs. Integrating these findings, a “Fault-Spring-Mud Volcano-Earthquake” fluid response model was established, providing direct evidence of deep-shallow fluid coupling in mud volcano–geothermal fluid interactions. This study enhances understanding of the dynamic evolution of non-volcanic geothermal systems under tectonic stress and clarifies the mechanisms of hydrogeochemical variations in fault-controlled geothermal systems, offering a robust scientific basis for advancing research on tectonic–fluid interactions in active fault zones of the northeastern Pamir Plateau. Full article

Wettability significantly influences fluid distribution and flow behavior in hydrocarbon reservoirs, yet traditional macroscopic measurements fail to capture the micro- and nanoscale interfacial interactions that govern these processes. This study addresses a critical knowledge gap by employing molecular dynamics simulations to systematically investigate how salinity and mineral composition control wettability at the atomic scale—insights that are experimentally inaccessible yet essential for optimizing enhanced oil recovery strategies. We examined five typical reservoir minerals—kaolinite, montmorillonite, chlorite, quartz, and calcite—along with graphene as a model organic surface. Our findings reveal that while all minerals exhibit hydrophilicity (contact angles below 75°), increasing salinity weakens water wettability, with Ca²⁺ ions exerting the strongest effect due to their high charge density, which enhances electrostatic attraction with negatively charged mineral surfaces and promotes specific adsorption at the mineral–water interface, thereby displacing water molecules and reducing surface hydrophilicity. In oil–water–mineral systems, we discovered that graphene displays exceptional oleophilicity, with hydrocarbon interaction energies reaching −7043.61 kcal/mol for C₁₈H₃₈, whereas calcite and quartz maintain strong hydrophilicity. Temperature and pressure conditions modulate interfacial behavior distinctly: elevated pressure enhances molecular aggregation, while higher temperature promotes diffusion. Notably, mixed alkane simulations reveal that heavy hydrocarbons preferentially adsorb on mineral surfaces and form highly ordered structures on graphene, with diffusion rates inversely correlating with molecular size. These atomic-scale insights into wettability mechanisms provide fundamental understanding for designing salinity management and wettability alteration strategies in enhanced oil recovery operations. Full article

Closed-loop geothermal systems (CLGSs) avoid groundwater production and offer stable deep heat supply, but their long-term performance hinges on reliable coupling between the wellbore, the near-well interface and the surrounding formation. Using the D22 well in the Xiongan New Area (deep carbonate reservoir), we built a three-domain thermo-hydraulic framework that updates CO₂ properties with temperature and pressure and explicitly accounts for wellbore-formation thermal resistance. Two geometries (U-tube and single-well coaxial) and two working fluids (CO₂ and water) were compared and optimized under field constraints. With the coaxial configuration, CO₂ delivers an average thermal power of 186.3 kW, exceeding that of water by 44.9%, while the fraction of wellbore heat loss drops by 3–5%. Under field-matched conditions, the predicted outlet temperature (76.8 °C) agrees with the measured value (77.2 °C) within 0.52%, confirming the value of field calibration for parameter transferability. Long-term simulations indicate that after 30 years of continuous operation the outlet temperature decline remains <8 °C for CO₂, outperforming water and implying better reservoir utilization and supply stability. Sensitivity and Pareto analyses identify a practical operating window, i.e., flow velocity of 0.9–1.1 m s⁻¹ and depth of 3000–3500 m, favoring the single-well coaxial + CO₂ scheme. These results show how field-calibrated modeling narrows uncertainty and yields implementable guidance on geometry, operating conditions, and wellbore insulation strategy. This study provides quantitative evidence that CO₂-CLGSs in deep carbonate formations can simultaneously increase thermal output and limit long-term decline, supporting near-term engineering deployment. Full article

Continental high water-cut reservoirs commonly exhibit strong heterogeneity, high viscosity, and insufficient reservoir drive, which has motivated the deployment of polymer-based composite chemical flooding, such as surfactant–polymer (SP) and alkali–surfactant–polymer (ASP) processes. However, conventional experimental techniques have limited ability to resolve intermolecular forces, and the coupled mechanism linking “formulation composition” to “microstructural evolution” remains insufficiently defined, constraining improvements in field performance. Here, scanning electron microscopy (SEM), backscattered electron (BSE) imaging, and molecular dynamics (MD) simulations are integrated to systematically investigate microstructural features of polymer composite systems and the governing mechanisms, including hydrogen bonding and electrostatic interactions. The results show that increasing the concentration of partially hydrolyzed polyacrylamide (HPAM) promotes hydrogen bond formation and the development of network structures; a moderate amount of surfactant strengthens interactions with polymer chains, whereas overdosing loosens the structure via electrostatic repulsion; the introduction of alkali reduces polymer connectivity, shifting the system toward an ion-dominated dispersed morphology. These insights provide a mechanistic basis for elucidating the behavior of polymer composite formulations, support enhanced chemical flooding performance, and ultimately advance the economic and efficient development of oil and gas resources. Full article