Overland flow resulting from the rainfall-runoff transformation is an important hydrological process in agricultural and urban watersheds, occurring in the form of a thin fluid sheet moving on rough and relatively steep terrain. Mixed flows involving moving critical points are frequent, especially in urban drainage, but a method to deal with these flows is so far not available. In this work a new and

We apply Smooth Particle Hydrodynamics (SPH) to simulate mass detachments in an overtopped and breached earth dam. SPH is able to model free surface flows at prototype and laboratory model scales. The flow over the overtopped dam is gravity-driven. Froude similarity is thus employed to scale results from models to prototypes, even if there are fluid-wall interactions. In particular, the processes that

Understanding of particle migration by fluid–particle interactions in immiscible two-phase flow systems in porous media is crucial for subsurface applications. However, pore-scale investigations of particle migration in immiscible two-phase flow systems remain limited for three-dimensional (3D) porous media because of the complexities of fluid flow in such media. Here, we employed microfocus X-ray

In complex fracture networks, dynamic fluid-flow patterns arise already at flow velocities in the centimetre-per-second (cm/s) range. Yet, these phenomena get ignored or underestimated when such flows are modelled using Stokes’ equation or the steady-state Darcy’s law approximations of the Navier–Stokes equation (NSE).

This contribution presents a gradient-based inverse modeling approach for the inference of distributed infiltration parameters in a 2D shallow water hydraulic model. It describes the implementation of rain and infiltration mass source terms in the DassFlow direct-inverse modeling platform and their validation against experimental data. Synthetic experiments are used to showcase the complexity of the

Soil moisture plays a critical role in land–atmosphere interactions. Prediction of its dynamics is still a grand challenge. While in-situ measurements using sensors offer highly temporally resolved and accurate information compared to satellite observations, existing sensor networks are sparse and scarce. Here we propose a deep learning model for bridging the gap between infrequent satellite observations

Shallow vortical flow can often occurs past (un)submerged topographies, prevailing in quasi-steady states with turbulence. Practically, vortical flow is represented by the two-dimensional (2D) Reynolds-Averaged Navier–Stokes equations, including the two-equation k-ε turbulent model (RANS-k-ε), and are commonly resolved by finite difference/volumes second-order accurate solvers. Such RANS-k-ε solvers

The successful treatment of contaminated soil and groundwater using thermal remediation technologies relies on the capture and treatment of contaminant vapour produced during heating. The migration of that vapour is affected by subsurface heterogeneity, which must be understood to ensure capture and to prevent condensation outside of a target heating zone. Bench-scale thermal conduction heating experiments

Spatial patterns of water table depth (WTD) play a crucial role in shaping ecological resilience, hydrological connectivity, and human-centric systems. Generally, a large-scale (e.g., continental or global) continuous map of static WTD can be simulated using either physically-based (PB) or machine learning-based (ML) models. We construct three fine-resolution (500 m) ML simulations of WTD, using the

In this study, an improved multi-scale algorithm was developed to analyze the effects of temperature on the bioclogging processes at pore and Representative Elementary Volume (REV) scales. In this algorithm, Immersed Boundary-Lattice Boltzmann Method- Cellular Automata (IB-LBM-CA) model for pore-scale simulation and Discrete Unified Gas-Kinetic Scheme-Cellular Automata (DUGKS-CA) model for REV simulation

This study presents an innovative mathematical framework that integrates a new analytical solution with the image-well method to model island aquifers under the combined influences of pumping, recharge, and complex coastline geometries. Past analytical solutions often rely on simplified boundary conditions and assume axially or radially symmetric coastline geometries, limiting their ability to address

Hydrodynamic simulation based on shallow water wave equations (SWE) is one of the most useful methods for flood routing analysis. However, its widespread application in large-scale basin flood disaster prevention is hindered by significant computational efficiency challenges. Addressing this issue, a hydrodynamic algorithm based on multi-GPUs is provided, and the program named as CoSim-SWE is developed

Porous geological formations play an important role as storage media for CO2 and H2. Brine in these formations can evaporate during gas injection, leading to salt precipitation. Estimating how and where salt precipitates is important to understand its influence on injectivity. So far, studies on gas injection scenarios primarily focused on formation dry-out inside the pore space. However, salt precipitation

Data assimilation will be essential for the management and expansion of geological carbon storage operations. In traditional data assimilation approaches a fixed set of geological hyperparameters, such as mean and standard deviation of log-permeability, is often assumed. Such hyperparameters, however, may be highly uncertain in practical CO2 storage applications where measurements are scarce. In this

Understanding CO2 capillary trapping and dissolution trapping behaviors in deep saline aquifers is essential for improvement of sequestration efficiency. This study investigated the impact of rock wettability on CO2 capillary and dissolution trapping in a Ketton carbonate rock through direct numerical simulation. Based on experimentally measured CO2-brine-rock physics data, we performed the pore-scale

We present a pioneering experimental study of stratified, rotating exchange flows interacting with a bottom, mobile sediment bed that simulates large estuaries. Two-dimensional velocity fields are coupled with bed scan that allows to reconstruct the bed morphology. The experiments span a large parameter range, notably laminar to turbulent Ekman layer regimes (33

Understanding the drivers of drought variability is crucial for developing effective adaptation and management strategies. This study develops a two-step modelling approach to characterize and predict hydrological droughts in a nonstationary context. First, a multivariate Hidden Markov Model (HMM) is used to classify low-water level time series into Dry, Normal, and Wet years, identifying Dry years

The present study experimentally investigated the evaporation-precipitation dynamics at sub-millimetric to millimetric scales in 1 M NaCl salt-DI water solution-based homogeneous porous media consisting of nearly mono-disperse glass beads (ranging from 0.10 to 2.50 mm) under controlled infrared heating from above, mimicking realistic field scenarios. Three diagnostic tools were employed simultaneously:

This experimental study systematically investigates the influence of the Peclet number (Pe) and transport length on the transition to Fickian transport in homogeneous sand packs. Through Darcy column experiments with varying lengths and two distinct sediment sizes (d50), we analyzed breakthrough curves (BTCs) to quantify non-Fickian characteristics and transport parameters. The dispersion coefficient

A falaj (plural aflaj) (also known as qanat) is a type of horizontal or nearly horizontal well that extracts water from an aquifer by gravity. Despite their importance, aflaj with arbitrary trajectories has not yet been mathematically modeled. Moreover, the available analytical models do not include the effects of several head losses, including head loss inside the falaj due to friction with the inner

Systems involving advection-dominated transport through heterogeneous porous and fractured media are ubiquitous in subsurface engineering applications. However, upscaling such systems continues to challenge rigorous modeling efforts, particularly when advection is stronger than diffusion at fine spatial scales (i.e., when the Péclet number is greater than one at length scales that characterize a system’s

The insecticide λ-cyhalothrin a type II synthetic parathyroid. It is a hydrophobic and highly effective broad-spectrum insecticide commonly used in pest management. However, its presence in subsurface formations poses environmental toxicity risks and potentially may have adverse effects on humans. Chitosan, a polymer with unique physicochemical and absorption properties, is utilized in numerous various

In surf/swash sediment transport in coastal processes, the influence of pore flow near the surface of the sediment bed cannot be ignored. Understanding how the pore flow affects the turbulent structure of the oscillating boundary layer is crucial for comprehending the mechanisms of bottom sediment transport. However, measurement is difficult and the turbulent structure in the porous sublayer is not

It is believed that channel networks across fluvial landscapes are self-organized into fractal patterns in order to minimize energy expenditure, as evidenced by the similarities between computer-generated optimal channel networks (OCNs) and real networks. However, the specific mechanisms driving such energy minimization remain largely elusive. Here, we propose that the energy minimization tendency

CO2 diffusive leakage, or diffusive transport, through intrinsic or induced caprock fractures poses a significant concern for the security of CO2 sequestration in saline aquifers. Although this issue has garnered considerable interest and has been the subject of many numerical analyses, experimental studies remain limited. We present the first experimental investigation of CO2 diffusive leakage through

Modeling breakthrough patterns in heterogeneous porous media during two-phase fluid flow presents unique challenges due to computational complexity and data scarcity. Current deep learning approaches, primarily generative adversarial network (GAN) based, focus on homogeneous media, limiting their practical application in real-world heterogeneous pore systems. In this work, we introduce FluidNet-Lite

Reactive transport (RT) simulations are important tools for understanding and predicting phenomena in the subsurface. However, RT is computationally intensive and complex simulations can be numerically unstable. Here, we present STAMNet, a low-parameter attention-based suite of neural nets that can upscale and upsample reactive transport simulations, applied to example problem of bioremediation in

The subsurface environment’s complex heterogeneous structure poses challenges for accurately modeling transport phenomena due to limited data and measurement errors, leading to uncertainties in solute transport predictions. This study proposes a computational framework to semi-analytically compute the cumulative distribution function (CDF) of solute concentration in heterogeneous aquifers. We investigate

Solute dispersion in the aqueous phase within unsaturated porous media has critical implications to various natural and engineered systems, such as nutrient and contaminant transport in the vadose zone. This work developed pore-scale lattice Boltzmann (LB) modeling to simulate water-air multiphase flow and solute transport in the aqueous phase, which unraveled the role of the water saturation and Peclet

The macroscopic behavior of multiphase flow systems is governed by interfacial dynamics, which are a strong function of the synergy between viscous forces and wettability. However, the effects of wettability heterogeneity, an inherent feature of natural porous media, remain poorly understood. In this study, we incorporated spatial-related wettability into phase field model and systematically examined

Characterizing velocity and pressure fields in aquatic systems is crucial for understanding fundamental processes such as sediment transport, hyporheic flow, air-water exchange, and habitat quality. While large obstacles like vegetation stalks are known to create significant localized pressure gradients, the role of small-scale bed roughness in generating local pressure gradients remains poorly understood

This study investigates the interplay among water saturation, hydraulic conductivity, and mechanical dispersion in heterogeneous porous media at the continuum scale. Mechanical dispersion of dissolved chemical tracers is influenced directly by water velocity variability, which is governed by the porous structure, the distribution of the water phase within it, and its corresponding conductivity field

The pore water retained in unsaturated soil includes film water attached on the solid surface and capillary water in corners or pores, which are mainly controlled by adsorptive force from the solid surface and capillary force from the water-gas interface, respectively. The soil water retention (SWR) curve represents the fundamental characteristic of unsaturated soil, in which the connected capillary

In many environmental flow situations, a solid body emerges from a sediment bed. This may occur in natural systems, for example when a tree-root emerges from the bed, or around a man-made structure such as a bridge pier or a wind turbine foundation. When this situation occurs, various flow-structure interactions such as the horseshoe vortex or vortex shedding lead to the scour process, namely the erosion

The current study is dedicated to the formal derivation of a hierarchic of asymptotic models that approximate the groundwater waves problem within the Dupuit–Forchheimer regime, over a regular, non-planar substratum. The derivation methodology employed bears resemblance to the techniques utilized in hierarchic of asymptotic models for approximating the water waves problem in the shallow water regime

Geological carbon storage (GCS) is critical for sequestering CO2 deep underground. GCS projects may face environmental challenges, such as leakage risks, adverse pressure buildup, and groundwater contamination. Numerical simulators play a vital role in accurate forecasting but can be computationally expensive. In this work, we leveraged an updated Fourier Neural Operator (FNO) which includes data sparsity

Female salmonids bury their eggs in streambed gravel by digging a pit where they lay their eggs, which they then cover with gravel from a second pit, forming a rough-surfaced dune-like structure called a redd. The interaction between a redd and the stream flow induces surface water to flow into the sediment, through egg pockets, and reemerge downstream of the crest. These downwelling and upwelling

Seawater intrusion can be mitigated by extracting saltwater, creating a negative hydraulic barrier that reduces the extent of saltwater in coastal aquifers. The effects of seawater extraction are analyzed in the current study through a semi-analytical methodology based on sharp-interface, steady-state conditions. The methodology is based on the Dupuit-Forchheimer approximation and applies a power series

We performed two-dimensional (2D) pore-scale simulations of primary CO2 injection using a weakly compressible scheme for geological carbon sequestration (GCS) applications. The aim was to analyze pore-scale relative permeability and saturation of CO2 under wide-ranging injection velocities and wettabilities. The results show that saturation is highest for viscous fingering, lowest for crossover (−

Colloidal-suspension-nano flows with varying ionic strength are widely present in nature and industry. The variation of brine salinity, which highly affects electrostatic particle-rock interaction, triggers fines detachment and consequent rock alteration. The microscale models for fines detachment at the pore-particle and at rock-reservoir scales are widely used to predict core and field behaviour

Understanding effective permeability is crucial for predicting fluid migration and trapping in subsurface reservoirs. The Bunter Sandstone of northwestern Europe hosts major groundwater and geothermal resources and is targeted for CO2 storage projects. Here the effective permeability of fluvial facies within the Bunter Sandstone Formation was assessed using facies-scale models. Twelve lithofacies were

We develop a phase-field model for evaporation from a porous medium by explicitly considering a vapor component together with the liquid and gas phases in the system. The phase-field model consists of the conservation of mass (for phases and vapor component), momentum, and energy. In addition, the evolution of the phase field is described by the Allen–Cahn equation. In the limit of vanishing interface

In this study, based on the minimum operating power principle, the potential control mechanism of nonmonotonic wetting effects in porous media is analyzed. When different wetting conditions are applied to the system, the contribution weights of different energy contribution terms are different during the process when the system approaches the minimum operating power state. For weak drainage or weak

The presence of tides and subsurface dams adds complexity to the migration and mixing processes of land-sourced contaminant in coastal aquifers. While prior studies have explored individual effect of tides and subsurface dams, their combined impact on the transport characteristics of land-sourced contaminant remains unclear. This study conducted laboratory experiments and numerical simulations to thoroughly

Estimations of multi-phase flow properties, mainly permeability, are crucial for several applications, such as CO2 sequestration, efficient oil and gas recovery, and groundwater contaminant treatment. Current methods for estimating the sub-core scale properties rely on numerical simulations, which can be time-consuming. A suitable alternative to numerical simulations is Deep Neural Networks (DNN),

A 3D macroscopic gradient-dynamics model is developed and applied to sandy soil in presence of exopolysaccharides (EPS), to mimic a soil influenced by root exuded mucilages (rhizospheric soil). Depending on water content, amphiphilic soil has a hydrophilic or hydrophobic behavior which impacts water transfer and retention. To model this saturation-dependent wettability, we propose a nonequilibrium

Coastal regions are vulnerable to flood risks due to the combined effects of storm surges, riverine flooding, upstream reservoir releases, and inland rainfall. Traditional models often fail to integrate these critical factors, leading to inaccuracies in flood extent forecasting. This study addresses this gap by developing a comprehensive coastal flood inundation forecasting framework for a region impacted

We present an experimental technique for determining the pH and the total carbon concentration when CO2 diffuses and flows in water. The technique employs three different pH indicators, which, when combined with an image analysis technique, provides a dynamic range in pH from 4.0 to 9.5. In contrast to usual techniques in which a single pH indicator is used, the methodology presented allows not only

Drainage of a liquid by a gas in porous media can be broken down into two main mechanisms: a primary piston-like displacement of the interfaces through the bulk of pore bodies and throats, and a secondary slow flow through corners and films in the wake of the invasion front. In granular porous media, this secondary drainage mechanism unfolds in connected pathways of pendular structures, such as capillary

In contrast to homogeneous soil deposits, stratified layering introduces vertical heterogeneity, resulting in not only greater spatial variability but also more complex structural responses. This complexity is further exacerbated by gravitational compaction, which gives rise to distinct fluid flow and solid deformation mechanics within each variably saturated layer and at the interfaces between layers—markedly

Kornev's (1935, see e.g. p.74, Fig. 34 - right panel) “open system” of capillarity-driven wetting of a fine-textured soil from a buried ditch filled by a coarse porous material is modeled analytically, using the methods of hodograph, and numerically, with the help of HYDRUS2D. Gravity, Darcian resistance of the soil at full saturation but negative pressure, and capillarity are three physical competing

CO2 injection into subsurface reservoirs provides a long-term solution to anthropogenic emissions. A variable injection rate (such as ramping the flow rate up or down) provides flexibility to injection sites, and could influence the amount of residual trapping. Observations made in cm-scale samples showed that starting at a low flow rate established a flow pathway across the core at a low capillary

We present a new approach to the discretisation and solution of the Shallow Water Equations (SWE) based on the finite element (FE) method. The discretisation is expressed as the convolutional layer of a neural network whose weights are determined by integrals of the FE basis functions. The resulting system can be solved with explicit or implicit methods. Expressing and solving discretised systems with

Aquitards, which widely occur throughout sedimentary basins or alluvial plains, play important roles in groundwater storage and contaminant transport. In this study, a mathematical model for one-dimensional contaminant transport which considered the combined effects of diffusion, adsorption and nonlinear consolidation deformation processes in an aquitard (NCD model) was formulated. An analytical solution

When a partially miscible fluid dissolves into a host phase below it, buoyancy-driven fingering develops when the diffusive boundary solution created is denser than the underlying solvent. In many situations, the interface between the two fluids may present level variations introduced by geometrical irregularities. We study here numerically the influence of this interface undulation on the properties

Hydraulic barriers are useful for manipulating groundwater flow to mitigate and contain harmful environmental effects. Injecting air into the aquifer has been suggested as a cost-efficient, sustainable, and reversible hydraulic barrier. In this, the injected air reduces the conductance of the aquifer to water flow. However, this practice is not commonly used despite its potential, probably due to a

Models of colloid transport in porous media that assume constant fractional loss per grain passed fail in the presence of repulsive barriers to attachment, under which condition experiments produce profiles of colloid concentrations with distance from source that are nonexponential. Nonexponential removal is hypothesized to arise from variable likelihood of encountering nanoscale regions of attraction

When performing upscaling of transport phenomena in multiscale systems it is not uncommon that terms of different physical nature than those present at the underlying scale arise in the resulting averaged differential equations. For diffusive species mass transfer with heterogeneous reaction and conductive heat transfer, additional terms result from upscaling using the volume averaging method, which

Dissolution in porous media is widespread in natural and engineered systems, accompanied by the evolution of geometric structure, permeability and surface area of the porous matrix. Although extensive research has examined dissolution dynamics in porous media, there is a lack of quantitative characterization of the relationships among permeability, surface area and porosity, which depend on dissolution