Article
Remote Sensing
Juan Wang, Shengtian Yang, Hezhen Lou, Huiping Liu, Pengfei Wang, Chaojun Li, Fei Zhang
Summary: Research on the response of river evolution to lake water level changes in the Ebinur Lake Basin over the past 5000 years revealed three geomorphic development stages and confirmed that human activities leading to a decline in lake water level will accelerate river erosion.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2021)
Article
Energy & Fuels
Shakhawat Hossain, Tahmidur Rahman Junayed, Naymur Rahman
Summary: This study utilized integrated channel belt dimension analysis to characterize fluvial reservoirs by combining seismic geomorphology, empirical equations, well log facies, and petrophysical analysis. It revealed the challenges of characterizing fluvial reservoirs due to their varying dimensions and connectivity.
Article
Geography, Physical
Maxwell P. Dahlquist, A. Joshua West
Summary: River incision in the Nepal Himalaya is influenced by glacial lake outburst floods (GLOFs), which mobilize large boulders and drive erosion. Through analysis of channel steepness, knickpoint distributions, and valley wideness, our study reveals a topographic signature consistent with widespread GLOF erosion. In rivers with glaciated headwaters that experience frequent GLOFs, valleys remain narrow and relatively sediment-free, allowing for efficient erosional regimes. In contrast, valleys in areas with less frequent GLOFs are more alluviated and incision stalls. The extent of headwater glaciation plays a significant role in the erosion of Himalayan river valleys.
EARTH SURFACE DYNAMICS
(2022)
Article
Geosciences, Multidisciplinary
Muhammad Tayyab Naseer, Ahmed E. Radwan, Shazia Naseem
Summary: This study focuses on the stratigraphic traps of point bars in fluvial depositional systems, and reveals their thickness and stratigraphic attributes using seismic data interpretation tools and inverted reservoir simulations. The results of this research are of great significance for exploring oil and gas-bearing stratigraphic systems.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Microbiology
Fei Ye, Yiguo Hong, Xuemei Yi, Zhaohong Sun, Jiapeng Wu, Yu Wang
Summary: The intricate associations between rhizosphere microbial communities and plants are crucial for soil ecological functioning. This study investigated the assembly patterns of rhizosphere fungal communities in different plant species and their responses to environmental changes. The results showed that the composition and alpha diversity of rhizosphere fungal communities varied significantly among plant species, with soil properties as the primary drivers. The assembly processes were driven by stochastic processes and were significantly related to changes in soil properties. The findings provide insights into the mechanisms of fungal community assembly in rhizosphere soils and their importance for maintaining ecosystem stability.
FRONTIERS IN MICROBIOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Wen Pan, Carlos Torres-Verdin, Michael J. Pyrcz
Summary: Accurately reproducing geological heterogeneity in subsurface models is critical but can be time-consuming and computationally intensive. Overfitting of data and slow convergence due to high dimensionality are common problems in modeling. To address these issues, a new machine learning approach is introduced to parameterize stochastic reservoir models into low-dimensional Gaussian random variables.
NATURAL RESOURCES RESEARCH
(2021)
Article
Automation & Control Systems
Angeliki Koutsimpela, Michail Loulakis
Summary: This study investigates the stochastic control problem of a shallow lake and expands on previous research by considering more general recycling rates. The authors prove approximate optimality under bounded controls and establish quantitative estimates. They also implement a numerical scheme to compute the value function and explore properties of the optimally controlled stochastic shallow lake, leading to the derivation of tails asymptotics for the invariant distribution.
INTERNATIONAL JOURNAL OF CONTROL
(2023)
Article
Environmental Sciences
Qingqing Tang, Daming Tan, Yongyue Ji, Lingyun Yan, Sidong Zeng, Qiao Chen, Shengjun Wu, Jilong Chen
Summary: The dynamics of mid-channel bars in the Three Gorges Reservoir were significantly affected by water-level changes caused by the impoundments of the reservoir. The morphological changes of the mid-channel bars were investigated using Landsat remote sensing images, showing dramatic changes in number, area, and shape with water level fluctuations. Water impoundments led to a shift in the dominant area and a more even distribution of mid-channel bars in the reservoir.
Article
Geosciences, Multidisciplinary
Isabel Terezinha Leli, Jose Candido Stevaux
Summary: Islands are crucial in multichannel fluvial systems for maintaining secondary channels and hosting important ecological environments. This study identified a new type of river island, known as lake-islands, which are characterized by their lenticular morphology and protective levees. Lake-islands can vary in shape and size, with sedimentary characteristics that depend on the flow regime and sedimentary load of the fluvial system.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Hu Yong, Xiao Juan, He Wenxiang, Gao Xiaoyang
Summary: The prediction of thin reservoir characteristics in block X of the Ordos Basin using sediment simulation technology and INPEFA technology provides a new idea for high-quality reservoir prediction, contributing to tight sandstone exploration in the area.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Environmental Sciences
Milad Hooshyar, Amilcare Porporato
Summary: Landscape evolution models commonly use coupled partial differential equations to model temporal dynamics of the land surface, accounting for sediment and water balance. The average sediment budget equation highlights the influence of curvature and surface divergence/convergence on erosion rate. A Reynolds-type averaging of the equations reveals a decomposition of erosion into unchannelized and channelized components, with the latter resembling Reynolds stress in fluid turbulence and indicating surface channelization statistical features.
WATER RESOURCES RESEARCH
(2021)
Article
Geology
Elena Bellizia, Sandra Donnici, Fantina Madricardo, Alvise Finotello, Andrea D'Alpaos, Massimiliano Ghinassi
Summary: This study focuses on the architectural features and sedimentary deposits of meandering subtidal channels in the Venice Lagoon. By integrating high-resolution geophysical images and core data, the researchers were able to reconstruct a three-dimensional model of a buried meandering subtidal palaeochannel. The study reveals the formation process of point bars and their relationship with channel sinuosity, as well as the influence of flow direction and topography on the sedimentation patterns.
Article
Geosciences, Multidisciplinary
Jiali Long, Hui Li, Zhaoyang Wang, Bo Wang, Yijun Xu
Summary: The study revealed a four-stage evolution process of bars in the middle Yangtze River, with both natural and human factors playing a role. The bar evolved more dynamically under natural flow conditions compared to regulated flow conditions.
Article
Geosciences, Multidisciplinary
Jacek Boguslaw Szmanda, Piotr Jacek Gierszewski, Michal Habel, Malgorzata Luc, Karol Witkowski, Sergii Bortnyk, Oleksandr Obodovskyi
Summary: The commission of the Kaniv dam in 1973 led to a complete change in the river regime, transforming the fluvial system of the Dnieper River from a braiding to an anastomosing system. The operation of the hydroelectric power plant had a significant impact on erosion and accumulation processes on the river bed, ultimately modifying the natural evolution of the river system.
Review
Geosciences, Multidisciplinary
Xiao Wu, Yao Yue, Alistair G. L. Borthwick, Louise J. Slater, Jaia Syvitski, Naishuang Bi, Zuosheng Yanga, Houjie Wang
Summary: Large reservoirs have significant impacts on the water-sediment dynamics and morphology of alluvial rivers. The anti-seasonal regulation mode of the Three Gorges Reservoir led to widespread downstream incision, while the swift drawdown process of the Xiaolangdi Reservoir effectively mitigated reservoir sedimentation and boosted sediment reaching the sea. Both reservoirs experienced vast sedimentation, causing erosion and coarsening downstream of the dams. The sediment deficits posed challenges to the sustainability of the Yangtze and Yellow river deltas.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Modeste Irakarama, Gautier Laurent, Julien Renaudeau, Guillaume Caumon
Summary: This paper introduces a new method for implicit structural modeling, focusing on new regularization operators extended from properties of classic one-dimensional discrete second derivative operator to higher dimensions. The proposed regularization operators naturally discretize on Cartesian grid, do not require special treatment on boundary nodes, and generalize straightforwardly to higher dimensions, making implementation simple. Numerical examples demonstrate the robustness and numerical efficiency of the proposed method.
MATHEMATICAL GEOSCIENCES
(2021)
Article
Geochemistry & Geophysics
Gabriel Godefroy, Guillaume Caumon, Gautier Laurent, Francois Bonneau
Summary: This paper introduces a method to generate interpretation scenarios for geological faults from incomplete spatial observations, aiming to help interpreters characterize how the lack of data affects geological structural uncertainty by honoring observations and geological interpretation concepts. The proposed method addresses the challenges of epistemic uncertainty during structural studies and quantifies subsurface uncertainty while preserving structural consistency.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geography, Physical
Yves Frantz, Pauline Collon, Philippe Renard, Sophie Viseur
Summary: This paper proposes different stochastic simulation methods to simulate the properties of karstic conduits on existing skeletons, providing a better assessment of uncertainties in conduit dimensions and demonstrating spatial correlations along and within the conduits. The study did not find evidence of an obvious link between conduit hierarchy within karstic networks and relative position regarding outputs.
Article
Geography, Physical
Dimitri Laurent, Christophe Durlet, Guillaume Barre, Patrick Sorriaux, Philippe Audra, Pierre Cartigny, Cedric Carpentier, Guillaume Paris, Pauline Collon, Thomas Rigaudier, Jacques Pironon, Eric C. Gaucher
Summary: Hypogenic caves, formed by deep waters rich in CO2 and H2S, make up over 10% of karstic networks worldwide. The interaction between hypogenic and epigenic processes is poorly understood, with the invasion of surface water often erasing markers of hypogenic activity. In the Ariege Valley, karstic networks have been reshaped by glacier meltwater, and deep fluids with CO2 and H2S played a key role in cave formation.
Article
Computer Science, Software Engineering
A. Paris, E. Guerin, A. Peytavie, P. Collon, E. Galin
Summary: The method presented in the text uses field data, geomorphological features, and parameters to compute skeletons of karstic networks and define geometry of conduits. The framework allows multiple levels of control for authoring the structure and details of the generated conduits.
COMPUTER GRAPHICS FORUM
(2021)
Article
Computer Science, Interdisciplinary Applications
Capucine Legentil, Jeanne Pellerin, Paul Cupillard, Algiane Froehly, Guillaume Caumon
Summary: In this study, a local updating method for geological models was proposed to assess the impact of gas-water contact depth on elastic wave propagation. The results show a positive correlation between depth difference and global L2-norm.
COMPUTERS & GEOSCIENCES
(2022)
Article
Geochemistry & Geophysics
Pierre Anquez, Nathalie Glinsky, Paul Cupillard, Guillaume Caumon
Summary: This study focuses on the numerical simulation of seismic wave propagation in realistic heterogeneous media and explores the simplification techniques for geological models to improve computational efficiency without significantly altering the physical response of the medium.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Paul Baville, Marcus Apel, Silvan Hoth, Dirk Knaust, Christophe Antoine, Cedric Carpentier, Guillaume Caumon
Summary: Computer-assisted stratigraphic correlation can help in producing scenarios reflecting interpretation uncertainties. The proposed method translates sedimentary concepts into correlation costs and applies them in Dynamic Time Warping algorithm to compute n-best correlation sets with least cumulative costs. The approach used in the article results in consistent stratigraphic well correlations, with sensitivity to facies zonation and relative well distality.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Computer Science, Software Engineering
Modeste Irakarama, Morgan Thierry-Coudon, Mustapha Zakari, Guillaume Caumon
Summary: This paper introduces a method for 3D implicit geological structural modeling from sparse sample points, discretizing Laplacian and Hessian energies on a tetrahedral mesh using finite elements. Boundary free discretizations of the Laplacian and Hessian energies are presented to eliminate boundary artifacts associated with vanishing Neumann boundary conditions.
COMPUTER-AIDED DESIGN
(2022)
Article
Geology
D. Laurent, G. Barre, C. Durlet, P. Cartigny, C. Carpentier, G. Paris, P. Collon, J. Pironon, E. C. Gaucher
Summary: This study quantifies the relative influence of microbial and thermochemical processes on sulfuric-acid production in two caves in the French Pyrenees using an innovative approach combining geomorphology with measurements of multiple sulfur, oxygen, and strontium isotopes. The results reveal the origin of sulfate speleothems and provide insights into the percentages of biotic and abiotic sulfuric-acid speleogeneses that have occurred in the caves, highlighting the need for similar studies in other sulfuric-acid caves where microbial activity is typically considered.
Article
Geosciences, Multidisciplinary
Khalifa Eldursi, Luc Scholtes, Marianne Conin, Fabrice Golfier, Patrick Ledru, Julien Mercadier, Pauline Collon, Remy Chemillac
Summary: Although favorable loci of basin-basement mineral deposits have been identified in previously studied intersecting fault arrays, their role in controlling fluid flow patterns for formation of oriented- and structurally-controlled mineral deposits remains unclear. This study conducted 3-D hydromechanical models to investigate the response of a natural fault intersected by a hydraulic fault under different stress regimes. The results showed that the intersection angle and horizontal differential stress have the most noticeable effect on fluid flow, with the critical intersection angle varying between approximately 27 to 55 degrees depending on the stress regime.
JOURNAL OF STRUCTURAL GEOLOGY
(2023)
Article
Geochemistry & Geophysics
Nicolas Clausolles, Pauline Collon, Modeste Irakarama, Guillaume Caumon
Summary: The paper presents a new stochastic geology-controlled velocity modeling method to handle salt weld. A large set of geologic scenarios and associated velocity models are generated, and each model is used to remigrate the seismic data. Statistical analysis of the resulting seismic images helps quantify the local variability of seismic responses. The method can effectively preserve recurrent features between different images and provide quantitative information on migration velocity variations.
INTERPRETATION-A JOURNAL OF SUBSURFACE CHARACTERIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Capucine Legentil, Jeanne Pellerin, Margaux Raguenel, Guillaume Caumon
Summary: We propose a workflow for updating 3D geological meshed models to assess the impact of different layering scenarios on CO2 injection simulation. This workflow operates on a tetrahedral mesh that encodes rock unit information and physical properties. Alternative layering meshes are built by modifying the input mesh and inserting a new horizon defined by a scalar field. The advanced capabilities of the open source remeshing library MMG are used to consistently modify the 3D meshed model while maintaining its quality. CO2 injection is then simulated using the open-source, multiphysics, and multilevel simulation solver GEOSX. The workflow is demonstrated on a synthetic layered reservoir to assess stratigraphic layering uncertainty.
APPLIED COMPUTING AND GEOSCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Lachlan Grose, Laurent Ailleres, Gautier Laurent, Guillaume Caumon, Mark Jessell, Robin Armit
Summary: Creating 3D geological models of faulted geological units is challenging without proper consideration of fault kinematics and observations of faulted surfaces, especially in cases of multiple faults interacting, significant deviation from flat plane geometry, and poorly characterized geological interfaces. Two existing approaches for fault incorporation have limitations in capturing fault interactions within complicated networks. A new approach integrating fault kinematics into implicit surface descriptions shows significant improvement in modeling faulted surface geometries and fault-fault interactions.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)