6,334 Works
Numerical Evaluation and Interpretation of Measured Effective Dielectric Permittivities during Two Phase Flow in a Porous Medium
Willem-Jan Plug, Johannes Bruining, Evert Slob, Ainhoa Gorriti & Willem-Jan Plug
An experimental procedure is presented where the capillary pressure and the
dielectric properties of a porous medium can be measured simultaneously. Our
objective is to determine a consistent relationship between capillary pressure
versus water saturation and its effect on the effective frequency dependent
dielectric permittivity. Applications are found in in-situ subsurface measurements
like Ground Penetrating Radar, borehole measurements and logging tools.
We have built an experimental set up that can measure capillary pressure under
various...
Two fuzzy and optimal models of water resources evaluation based on the Principle of Maximum Entropy (POME) and Engineering Fuzzy Set Theory
WANG Dong & WANG Dong
The randomness of characteristic value of water resources evaluation is inevitable
during its monitoring, experimenting, and data analyzing, as a result of the
physical process, the chemical process and biological process of water
contamination are all stochastic process. On the other hand, the fuzziness of water
resources evaluation is also inevitable, for the classification standard, the
evaluation class and pollution degree is impersonal fuzzy concept and phenomenon.
Entropy is a very important scientific conception. The...
Period characteristics of representative hydrologic series in the Yellow River in China using maximum entropy spectra analysis(MESA)
WANG Dong & WANG Dong
In the field of stochastic hydrology, hydrologic series is formed with the non-
periodic component, the periodic component and the stochastic component. Here the
period characteristics used include approximate periods in the non-periodic
component, simple periods and complex periods in the periodic component. Spectral
analysis is an essential and effective tool for extracting such stochastic
characteristics of time series. In 1948, Shannon developed a mathematical theory of
entropy and applied it in communications. Nearly a...
Connectivity of fracture networks: The effects of anisotropy and spatial correlation
Mohsen Masihi, Peter R King, Peyman Nurafza & Mohsen Masihi
In fractured formations of very low matrix permeability connectivity of fractures
is a crucial parameter which may have a significant impact on the overall flow. The
connectivity behaviour of fracture networks can be analysed by using percolation
theory. The scaling law within this theory is used to predict the connectivity and
its associated uncertainty very rapidly. Although the effects of some geometrical
parameters of fractures (e.g. size distribution) on the universal connectivity
curves are extensively...
Connectivity of fracture networks: The effects of anisotropy and spatial correlation
Mohsen Masihi, Peter R King, Peyman Nurafza & Mohsen Masihi
In fractured formations of very low matrix permeability connectivity of fractures
is a crucial parameter which may have a significant impact on the overall flow. The
connectivity behaviour of fracture networks can be analysed by using percolation
theory. The scaling law within this theory is used to predict the connectivity and
its associated uncertainty very rapidly. Although the effects of some geometrical
parameters of fractures (e.g. size distribution) on the universal connectivity
curves are extensively...
ESTIMATING SURFACE FLUXES IN IRRIGATED AREAS WITH SCINTILLOMETERS
Oscar Hartogensis, Henk De Bruin & Oscar Hartogensis
Scintillometry has proven to be a good alternative method to obtain surface fluxes
over heterogeneous areas over spatial scales of up to 10 km and in non-stationary
conditions in the stable surface layer (see e.g. [1]). This study concerns agro-
hydrological scintillometer applications of estimating evaporation over homogeneous
irrigated areas on a scale of 50 to 500 m. Two types of scintillometers will be
considered, notably the displaced beam small aperture scintillometer (DBSAS) and the...
An Integrated Media, Integrated Processes Watershed Model – WASH123D: Part 5 – Integrated modeling of surface water and groundwater interactions in a constructed wetland
GUOBIAO HUANG, Gour-Tsyh Yeh & Gour-Tsyh Yeh
A pilot constructed wetland in south Florida, USA, the Everglades Nutrient Removal
(ENR) project was modeled with a physics-based integrated approach by WASH123D.
Stormwater is routed into the treatment wetland for phosphorus removal by plant and
sediment intake. It overlies a highly permeable surficial groundwater aquifer.
Strong surface water and groundwater interactions are a key component of the
hydrologic processes. The site has extensive field measurement and monitoring that
provide point scale and distributed data...
An Integrated Media, Integrated Processes Watershed Model – WASH123D: Part 5 – Integrated modeling of surface water and groundwater interactions in a constructed wetland
GUOBIAO HUANG, Gour-Tsyh Yeh & Gour-Tsyh Yeh
A pilot constructed wetland in south Florida, USA, the Everglades Nutrient Removal
(ENR) project was modeled with a physics-based integrated approach by WASH123D.
Stormwater is routed into the treatment wetland for phosphorus removal by plant and
sediment intake. It overlies a highly permeable surficial groundwater aquifer.
Strong surface water and groundwater interactions are a key component of the
hydrologic processes. The site has extensive field measurement and monitoring that
provide point scale and distributed data...
Volume of Fluid Simulations of Multiphase Flow through Fractures: Analysis of Individual Fractures for Application in Reservoir Scale Models
Dustin Crandall, Kambiz Nazridoust, Goodarz Ahmadi, Grant Bromhal, Duane Smith & Duane Smith
Geological Carbon Dioxide Sequestration requires a fundamental understanding of
modeling multiphase flows in fractured media. Subsurface flow is highly dependent
upon the rock structure within the flow domain, with high permeability and
fractured regions dominating the transport of the fluids. Discrete-fracture
simulators often assume the cubic law relationship for single phase flow through a
smooth set of parallel plates, and with good reason. The number of fractures that
need to be modeled at the reservoir...
WELL CATCHMENTS ESTIMATION IN HETEROGENEOUS AQUIFERS WITH A STRATIFIED MODEL
Paolo Salandin, Filomena Savini, Gianluca Marconi & Gianluca Marconi
A new method is proposed to delimitate wellhead protection areas in a confined
aquifer where hydraulic conductivity is assumed as spatially random function. In a
natural formation the heterogeneity of porous media influences the capture zone
delimitation and considerable differences can result from the homogenous case. In
the last decade several approaches were proposed to solve the problem but they need
of a priori description of statistical properties of aquifer that are usually
unknown or...
Scale Dependent Fluid Momentum and Solute Mass Macroscopic Balance Equations: Theory and Observations
Shaul Sorek, Daniel Ronen & Shaul Sorek
A mathematical development is presented concerning extensions to the macroscopic
momentum balance equation for compressible Newtonian fluids flowing through
saturated porous matrices, and the macroscopic mass balance equation of solutes
transported with the fluids.
It is shown that each of these balance equations is composed of a dominant
macroscopic equation associated with a larger spatial scale, coupled with a
secondary macroscopic balance equation valid at a smaller spatial scale. The
dominant fluid momentum balance equation...
Darcy multi-domain approach for integrated surface/subsurface hydrologic models
Sylvain WEILL, Emmanuel MOUCHE & Sylvain WEILL
A Darcy multi-domain approach for modeling surface and subsurface hydrologic
processes is presented. The diffusive wave approximation is used to model runoff. The
resulting equation is formulated as a Darcy nonlinear one. Therefore, the water
dynamics in the three physical domains, ground surface, vadose zone and saturated
zone, is described through a single Darcy nonlinear equation with domain-dependent
parameters. This multi-domain Darcy equation is solved with Mixed Hybrid Finite
Element formulation. The time discretisation is...
Darcy multi-domain approach for integrated surface/subsurface hydrologic models
Sylvain WEILL, Emmanuel MOUCHE & Sylvain WEILL
A Darcy multi-domain approach for modeling surface and subsurface hydrologic
processes is presented. The diffusive wave approximation is used to model runoff. The
resulting equation is formulated as a Darcy nonlinear one. Therefore, the water
dynamics in the three physical domains, ground surface, vadose zone and saturated
zone, is described through a single Darcy nonlinear equation with domain-dependent
parameters. This multi-domain Darcy equation is solved with Mixed Hybrid Finite
Element formulation. The time discretisation is...
Drainage with Unfavorable Viscosity Ratios: a pore-level model study
Martin Ferer, Grant Bromhal, Duane Smith & Martin Ferer
The applications of carbon dioxide sequestration in brine-saturated reservoirs,
as well as recovery of oil from oil-wet reservoirs, involve the injection of a less-
viscous, non-wetting fluid into a porous medium occupied by a more-viscous, wetting
fluid: i.e., drainage with an unfavorable viscosity ratio. In these cases, there is
a competition between capillary fingering and viscous fingering.
In standard treatments of two-phase flow in porous media, the flow is assumed
to be compact, with a...
Chemistry-Transport coupling : Implicit schemes keeping a code coupling approach
Raphaèle Herbin, Philippe Montarnal, Nicolas Bouillard & Nicolas Bouillard
This work is linked with the field of reactive transport simulations in the context
of reactive waste storage in deep geological disposals. Indeed, the evolution of the
different materials and the species migration are deeply influenced by chemical,
hydraulic and transport interactions.
For these modeling issues it is necessary to deal with numerical codes involving
combined effect of transport and multiple geochemical species within groundwater
flow. Currently, many of the codes use a sequential iterative...
Monitoring unsaturated flow and transport using cross-borehole geophysical methods
Majken C Looms, Karsten H Jensen, Lars Nielsen, Andrew Binley, Hans Thybo & Majken C Looms
Recent research has shown that cross-borehole georadar and electrical resistivity
tomography (ERT) can provide data on soil moisture content and conductivity
variations in the vadose zone at a more appropriate spatial scale than traditional
techniques.
A field site has been established in Denmark on a 20-30 m layer of unsaturated melt
water sand and gravel deposits. Two identical field setups have been established
each having four ERT and four georadar boreholes. The boreholes are drilled...
Streamline methods on fault adapted grids for risk assessment of storage of CO2 in geological formations
Håkon Hægland, Helge Dahle, Geir Terje Eigestad, Michael Celia, Jan Martin Nordbotten, Erlend Øian & Håkon Hægland
Streamline methods have shown to be effective for reservoir
characterization and simulation.
In this work we will
develop methodology which allows for tracing of streamlines in
fractured or faulted media including anthropogenic faults such as
abandoned wells.
The basis for a streamline method is a
sequential splitting of the
coupled pressure and saturation equations.
A mass-conservative
discretization, which handles general faulted grids in a consistent
manner, will be used for
the pressure equation.
The fact...
BGK Boltzmann Model and Lattice Boltzmann Method for Shallow Water Flows
Junhong LIANG, Mohamed GHIDAOUI & Junhong LIANG
Both the Bhatnagar-Gross-Krook (BGK) Boltzmann model and Lattice Boltzmann method
(LBM) are based on the numerical discretization of the Boltzmann equation with
collisional models, such as, the BGK model. The BGK Boltzmann scheme is a finite
volume scheme, where the time-dependent distribution function with continuous
particle velocity space is constructed and used in the evaluation of the numerical
fluxes across cell interfaces. On the other hand, LBM tracks limited number of
particles and the viscous...
APPLICATION OF ACO ALGORITHM IN SCS-CN METHOD
Mortazavi Naeini Seyed Mohammad, P. Suresh Babu & Mortazavi Naeini Seyed Mohammad
Calibrating the most appropriate parameter is one of the crucial stages in
dependable rainfall-runoff modeling. This paper evaluates the computational
performance of Ant Colony Optimization (ACO) and Marquardt Algorithms (MA) used for
calibration of CN and λ parameters of the Soil Conservation Service Curve Number
(SCS-CN) model in optimization. Employing standard error of estimate (Se) and
standard error ratio (SER), the performance of both the algorithms was tested on a
large set of US data.
Parallelization of the WASH123D Code—Phase III: 1-Dimensional Channel, 2-Dimensional Overland, and 3-Dimensional Subsurface Flows
Jing-Ru Cheng Cheng, Robert Hunter, Hwai-Ping Cheng, David Richards & Jing-Ru Cheng Cheng
Watershed models are used to simulate and predict major hydrological processes, such
as surface or subsurface flows, which may occur on different spatial domains and
temporal scales. A key feature of watershed models is the ability to model
interactions among different processes and domains. Such interactions can be
strongly or weakly coupled depending on the relevant time scales for each process.
WASH123D is a first-principles, physics-based model for simulating a coupled system
of channel flow,...
Discontinous Galerkin Methods for the Sahllow-Water Equations with bathymetric terms and dry areas
Karim DJADEL, Alexandre ERN, Serge PIPERNO & Karim DJADEL
In this paper, we develop Discontinuous Galerkin Methods to deal with the
Shallow-Water Equations involving bathymetric temrms and dry areas. Our major goals
are on the one hand to preserve quiescent flows and, more generally, steady-states
and on the other hand to ensure stability when the flow includes flooding and drying.
Drawing on earlier ideas for Finite Volume Methods [Aud,Ber], we design two
Discontinuous Galerkin Methods that preserve flows at rest. We investigate their
acuracy...
Application of Ant Algorithm in Calibration of Rainfall-Runoff Model
Mortazavi Naeini Seyed Mohammad, Alireza B.Dariane & Mortazavi Naeini Seyed Mohammad
The successful application of a conceptual rainfall-runoff (CRR) model depends on
how it is calibrated. The CRR models generally represent the soil moisture
accounting phase of the hydrologic cycle as several interconnected subsystems, each
representing a certain component in the processing of the hydrologic event. Despite
the popularity of CRR models, reports in the literature indicate that difficulties
in calibrating the parameters.
Ant Colony Optimization (ACO) is one of the recent optimization methods which is...
Pore network modeling of convective drying
Andreas Yiotis, Ioannis Tsimpanogiannis, Athanassios Stubos, Yanis Yortsos & Andreas Yiotis
Drying of porous media is a process of significant scientific and applied interest.
It involves several mechanisms at the pore scale that affect the macroscopic behavior
of the drying process. These include phase change at the liquid-gas interface, mass
and heat transfer by diffusion and convection, capillarity-induced flow through
wetting liquid films and the receding of the liquid gas interfaces under combined
viscous, capillary and buoyancy forces.
In most typical applications, porous materials are subjected...
A structural approach to joint inversion of hydrogeophysical data
Niklas Linde, Andrew Binley, Ari Tryggvason, Laust Pedersen & Niklas Linde
We have developed a flexible methodology to jointly invert different types of
geophysical and hydrogeological data, where the resulting models honour the spatial
correlation structure derived from geophysical borehole logs. Additionally, the
individual models are internally consistent. The key components in this work are:
(1) an efficient method to estimate stochastic regularization operators based on
geostatistical models; (2) to minimize the cross product of the gradients of two
models, which is used as a measure...
Reconstruction of the three-dimensional Darcy velocity in a small catchment using self-potential, electrical resistivity, and induced polarization data
Niklas Linde, André Revil, Barbara Suski, Cécile Dagès, Marc Voltz & Niklas Linde
One of the ultimate goals of hydrogeophysics is to map the groundwater table
throughout a catchment and together with information about hydrogeological
properties of the saturated zone, derived from geophysical and hydrogeological
data, estimate the Darcy velocity in three dimensions throughout the saturated
zone. In this work, we present our first attempts to achieve this goal in the small
(~1 km2) catchment area of Roujan (Hérault, France), which is a well characterized
hydrogeological research site....
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