Skip to main content

Rachid ABABOU

IMFT, GEMP, Faculty Member

Followers

56

Following

16

Co-authors

7

Mentions

1

Public Views

Rachid ABABOU, Prof. Emeritus,Dr-Ing (INP Grenoble), PhD (MIT), Institut National Polytechnique de Toulouse, CNRS University of Toulouse, France Professional address: Institut de Mécanique des Fluides de Toulouse, 2 Allée du professeur Camille Soula, 31400, Toulouse, France

less

Jean-François Deliège

Jean-Luc Probst

Centre National de la Recherche Scientifique / French National Centre for Scientific Research

Philippe Vervier

МГУ

Bernard Barnier

Vincent Chatain

INSA Lyon

Institut National de la Recherche Agronomique

aurélie LE DISSEZ

Interests

Uploads

Papers by Rachid ABABOU

Couplages de modèles en hydrodynamique environnementale et hydrologie (sols, nappes, rivières, zones côtières)

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Upscaling Theory for Coupled Hydro-Mechanics in 3D Fractured Porous Rock

Random walk in heterogeneous media: Comparison between sharp and smooth interface methods

AGU Fall Meeting Abstracts, Dec 1, 2012

Infiltration in unsaturated porous media

We review infiltration models for unsaturated porous media, including the piston flow model of Gr... more We review infiltration models for unsaturated porous media, including the piston flow model of Green & Ampt, and a recent extension called « Moving Multi-Front (MMF) » which propagates a discrete number of « fronts » or pressure iso-values (Alastal & Ababou 2019). The MMF model is quasi-analytical, gridless. It reduces the Richards PDE to a system of ODE's governing the positions of the fronts. We compare it to a finite volume model (BIGFLOW3D) and a finite element model (HYDRUS1D) for infiltration to a water table, capillary rise, etc. The results are encouraging in terms of CPU time and precision. Finally, we analyze other infiltration phenomena with the general Richards PDE solver BIGFLOW3D : dynamics of 2D/3D wetted zone during localized infiltration ; effects of heterogeneities (perched water, discontinuous humidity profiles, etc.). Résumé On passe en revue certains modèles d'infiltration en milieux poreux non saturés, incluant l'écoulement piston de Green & Ampt, et une extension récente dite "Moving Multi-Front (MMF)" qui propage un nombre discret de "fronts" ou iso-valeurs de pression (Alastal & Ababou 2019). Le modèle MMF est quasi-analytique, "sans grille". Il réduit l'EDP de Richards à un système différentiel régissant les positions des "fronts". On le compare à des modèles volumes finis (BIGFLOW3D) ou éléments finis (HYDRUS1D), pour une infiltration vers une nappe, une ascension capillaire, etc. Les résultats sont encourageants en temps calcul et en précision. Enfin, on analyse d'autres phénomènes d'infiltration avec le code BIGFLOW3D (solveur général de l'EDP de Richards) : dynamique du bulbe humide en infiltration localisée 2D/3D ; effet des hétérogénéités (eaux perchées, profils discontinus d'humidité, etc.).

Travel path uncertainty: a case study combining stochastic and deterministic hydrodynamic models in the Rhône valley, Switzerland

In the framework of waste storage in geological formations at shallow or greater depths and accid... more In the framework of waste storage in geological formations at shallow or greater depths and accidental pollution, the numerical simulation of groundwater flow and contaminant transport represents an important instrument to predict and quantify the pollution as a function of time and space. The numerical simulation problem, and the required hydrogeologic data, are often approached in a deterministic fashion. However, deterministic models do not allow to evaluate the uncertainty of results. Furthermore, the hydrogeologic data and hydrodynamic properties required to implement the flow-transport model are generally very scant, so that an essential part of the simulation effort needs to be devoted to building the different spatially distributed data through spatial interpolation, extrapolation, smoothing, etc. In this paper, deterministic (classic finite element hydrodynamic model) and stochastic approaches (geostatistics : kriging and conditional simulations) are used for evaluating groundwater flow patterns and pollutant trajectories for a site-specific application (Rhône valley aquifer in Switzerland, area of 6.5 km 2). The stochastic approach, based on kriging and multiple conditional simulations, leads to a quantification of uncertainty of flow-transport simulations, which are due to the underlying uncertainty of hydrogeologic properties and their spatial distribution. The available data used in this case study are : 55 transmissivity, 791 permeability and 145 hydraulic potential values. In spite of the relative wealth of available data, our study shows that the uncertainty of pollutant migration pathlines and travel distances is relatively important. The distance traveled by a pollutant particle during 30 monthes varies between 3150 m and 4800 m over five different but equally plausible scenarios (conditional simulations). The uncertainty is about 42% relative to the average travel distance, or 55% relative to the smallest travel distance mentioned above.

Maitrise de l'eau dans les bassins mediterraneens. (Etude de l'irrigation localisee)

HAL (Le Centre pour la Communication Scientifique Directe), 1981

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Seismic waves in randomly heterogeneous media: multiple scattering dispersion and attenuation

$Research paper thumbnail of Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media$

Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

$Research paper thumbnail of Equivalent permeability tensor in fractured media : an algebraic approach$

Equivalent permeability tensor in fractured media : an algebraic approach

HAL (Le Centre pour la Communication Scientifique Directe), May 23, 2011

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Numerical analysis of nonlinear unsaturated flow equations

An Alternative Approach to Simulate Transport Based on the Master Equation

IAHS-AISH publication, 2000

Analyse en ondelettes en hydrologie karstique. 2e partie: analyse en ondelettes croisée pluie-débit

Comptes rendus de l'Académie des sciences. Série 2. Sciences de la terre et des planètes, Dec 1, 1999

A method of cross-analysis of rainfall-runoff time series based on wavelet transforms (continuous... more A method of cross-analysis of rainfall-runoff time series based on wavelet transforms (continuous Morlet wavelet transform and orthogonal multiresolution analysis), is presented and applied to rainfall rates and spring outflow rates measured on karstic Pyrenean watersheds. Results are compared to classical cross-correlation and Fourier cross-spectral analyses. The multiscale wavelet method appears as powerful in the study of the joint temporal variability and non-stationarity of the rainfall-runoff relationship, and it yields more precise results than Fourier cross-spectral analysis. (0 1999 Acadkmie des sciences / kditions scientifiques et medicales Elsevier SAS.) Note prbentke par Ghislain de Marsily.

Salt water intrusion with heterogeneity and uncertainty: mathematical modeling and analyses

Developments in water science, 2004

ABSTRACT

Equivalent Permeability Tensor of Heterogeneous Media: Upscaling Methods and Criteria (Review and Analyses)

Geosciences, Jul 1, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more

Stochastic Flow Analysis of Flux Variances in Heterogeneous Porous Media

Springer eBooks, 1994

Three-dimensional (3-D) groundwater flow is simulated numerically in a porous medium characterize... more Three-dimensional (3-D) groundwater flow is simulated numerically in a porous medium characterized by an isotropic or anisotropic stationary conductivity field. The solution is obtained by the finite element technique by discretizing the medium into 60 x 60 x 60 elements. Various simulations are performed for different variances of lnK and anisotropy ratios. Analytical expressions for second-order moments of the flux field, are compared with numerical results. The kinetic energy of the velocity fluctuations is also studied.

Effect and propagation of water level fluctuations in a sloping sandy beach -- Unsaturated porous media II: numerical simulation test of single harmonic wave (long run)

HAL (Le Centre pour la Communication Scientifique Directe), May 18, 2012

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Quantitative Stochastic Hydrogeology: The Heterogeneous Environment

Springer eBooks, Feb 1, 2008

... that very complex spatial patterns can be efficiently represented based on a stochastic appro... more

Comment on “Effective groundwater model parameter values: Influence of spatial variability of hydraulic conductivity, leakance, and recharge” by J. J. Gómez-Hernández and S. M. Gorelick

Water Resources Research, Aug 1, 1990

In a recent paper, G6mez-Herndndez and Gorelick [1989] studied the effective conductivity and the... more In a recent paper, G6mez-Herndndez and Gorelick [1989] studied the effective conductivity and the statistics of hydraulic heads in a bounded two-dimensional unconfined aquifer with pumping wells, assuming for the most part that hydraulic conductivity is a two-dimensional random field. The objective of this paper is to present a few constructive comments on their statistical analysis of heads and effective conductivity in the presence of pumping wells. Our comments are divided into three parts. First, we address a technical point concerning the statistics of lognormal conductivity random fields and suggest a closed form expression for the p norm which would have simplified their investigation of effective conductivity. Second, we comment on the behavior of head variance at the wells with respect to pumping rates and indicate how their Monte Carlo results relate to earlier theories. Third, we discuss the effective behavior of nonuniform flow systems and attempt to explain their effective conductivity results in connection with earlier theoretical works, plus some modest extensions of our own. We will not consider in this discussion the effects of random recharge and river leakage, which they analyzed separately. 2. THE p NORM OF LOGNORMAL RANDOM FIELDS In their paper, G6mez-Herndndez and Gorelick [1989] assumed for the most part that hydraulic conductivity K(x) is a two-dimensional random field and that the log-conductivity field In (K(x)) is itself normally distributed and stationary. The two-point covariance of In (K) was an exponentially decaying isotropic function (more on this choice later). The authors used this model to obtain via Monte-Carlo simulations the effective conductivity K e that "best fits" the simulated hydraulic heads in some least squares sense. Moreover, they chose to relate the resulting value of K e to the p norm of the random conductivity field, which they defined numerically as Kp =. (Ki) • (1) where p is a real number-1-< p-< +1. Briefly, their procedure was as follows. They plotted the bias and error variance of the hydraulic heads, where the error is the difference between the heads for randomly generated repli

John Wiley & Sons, Inc. eBooks, Jan 21, 2013

Groundwater Quality Assessment Using Water Quality Index (WQI) Approach - Gaza Coastal Aquifer as A Case Study

Couplages de modèles en hydrodynamique environnementale et hydrologie (sols, nappes, rivières, zones côtières)

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Upscaling Theory for Coupled Hydro-Mechanics in 3D Fractured Porous Rock

Random walk in heterogeneous media: Comparison between sharp and smooth interface methods

AGU Fall Meeting Abstracts, Dec 1, 2012

Infiltration in unsaturated porous media

We review infiltration models for unsaturated porous media, including the piston flow model of Gr... more We review infiltration models for unsaturated porous media, including the piston flow model of Green & Ampt, and a recent extension called « Moving Multi-Front (MMF) » which propagates a discrete number of « fronts » or pressure iso-values (Alastal & Ababou 2019). The MMF model is quasi-analytical, gridless. It reduces the Richards PDE to a system of ODE's governing the positions of the fronts. We compare it to a finite volume model (BIGFLOW3D) and a finite element model (HYDRUS1D) for infiltration to a water table, capillary rise, etc. The results are encouraging in terms of CPU time and precision. Finally, we analyze other infiltration phenomena with the general Richards PDE solver BIGFLOW3D : dynamics of 2D/3D wetted zone during localized infiltration ; effects of heterogeneities (perched water, discontinuous humidity profiles, etc.). Résumé On passe en revue certains modèles d'infiltration en milieux poreux non saturés, incluant l'écoulement piston de Green & Ampt, et une extension récente dite "Moving Multi-Front (MMF)" qui propage un nombre discret de "fronts" ou iso-valeurs de pression (Alastal & Ababou 2019). Le modèle MMF est quasi-analytique, "sans grille". Il réduit l'EDP de Richards à un système différentiel régissant les positions des "fronts". On le compare à des modèles volumes finis (BIGFLOW3D) ou éléments finis (HYDRUS1D), pour une infiltration vers une nappe, une ascension capillaire, etc. Les résultats sont encourageants en temps calcul et en précision. Enfin, on analyse d'autres phénomènes d'infiltration avec le code BIGFLOW3D (solveur général de l'EDP de Richards) : dynamique du bulbe humide en infiltration localisée 2D/3D ; effet des hétérogénéités (eaux perchées, profils discontinus d'humidité, etc.).

Travel path uncertainty: a case study combining stochastic and deterministic hydrodynamic models in the Rhône valley, Switzerland

In the framework of waste storage in geological formations at shallow or greater depths and accid... more In the framework of waste storage in geological formations at shallow or greater depths and accidental pollution, the numerical simulation of groundwater flow and contaminant transport represents an important instrument to predict and quantify the pollution as a function of time and space. The numerical simulation problem, and the required hydrogeologic data, are often approached in a deterministic fashion. However, deterministic models do not allow to evaluate the uncertainty of results. Furthermore, the hydrogeologic data and hydrodynamic properties required to implement the flow-transport model are generally very scant, so that an essential part of the simulation effort needs to be devoted to building the different spatially distributed data through spatial interpolation, extrapolation, smoothing, etc. In this paper, deterministic (classic finite element hydrodynamic model) and stochastic approaches (geostatistics : kriging and conditional simulations) are used for evaluating groundwater flow patterns and pollutant trajectories for a site-specific application (Rhône valley aquifer in Switzerland, area of 6.5 km 2). The stochastic approach, based on kriging and multiple conditional simulations, leads to a quantification of uncertainty of flow-transport simulations, which are due to the underlying uncertainty of hydrogeologic properties and their spatial distribution. The available data used in this case study are : 55 transmissivity, 791 permeability and 145 hydraulic potential values. In spite of the relative wealth of available data, our study shows that the uncertainty of pollutant migration pathlines and travel distances is relatively important. The distance traveled by a pollutant particle during 30 monthes varies between 3150 m and 4800 m over five different but equally plausible scenarios (conditional simulations). The uncertainty is about 42% relative to the average travel distance, or 55% relative to the smallest travel distance mentioned above.

Maitrise de l'eau dans les bassins mediterraneens. (Etude de l'irrigation localisee)

HAL (Le Centre pour la Communication Scientifique Directe), 1981

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Seismic waves in randomly heterogeneous media: multiple scattering dispersion and attenuation

$Research paper thumbnail of Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media$

Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media

$Research paper thumbnail of Equivalent permeability tensor in fractured media : an algebraic approach$

Equivalent permeability tensor in fractured media : an algebraic approach

HAL (Le Centre pour la Communication Scientifique Directe), May 23, 2011

OATAO is an open access repository that collects the work of Toulouse researchers and makes it fr... more

Numerical analysis of nonlinear unsaturated flow equations

An Alternative Approach to Simulate Transport Based on the Master Equation

IAHS-AISH publication, 2000

Analyse en ondelettes en hydrologie karstique. 2e partie: analyse en ondelettes croisée pluie-débit

Comptes rendus de l'Académie des sciences. Série 2. Sciences de la terre et des planètes, Dec 1, 1999

A method of cross-analysis of rainfall-runoff time series based on wavelet transforms (continuous... more A method of cross-analysis of rainfall-runoff time series based on wavelet transforms (continuous Morlet wavelet transform and orthogonal multiresolution analysis), is presented and applied to rainfall rates and spring outflow rates measured on karstic Pyrenean watersheds. Results are compared to classical cross-correlation and Fourier cross-spectral analyses. The multiscale wavelet method appears as powerful in the study of the joint temporal variability and non-stationarity of the rainfall-runoff relationship, and it yields more precise results than Fourier cross-spectral analysis. (0 1999 Acadkmie des sciences / kditions scientifiques et medicales Elsevier SAS.) Note prbentke par Ghislain de Marsily.

Salt water intrusion with heterogeneity and uncertainty: mathematical modeling and analyses

Developments in water science, 2004

ABSTRACT

Equivalent Permeability Tensor of Heterogeneous Media: Upscaling Methods and Criteria (Review and Analyses)

Geosciences, Jul 1, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more

Stochastic Flow Analysis of Flux Variances in Heterogeneous Porous Media

Springer eBooks, 1994

Three-dimensional (3-D) groundwater flow is simulated numerically in a porous medium characterize... more Three-dimensional (3-D) groundwater flow is simulated numerically in a porous medium characterized by an isotropic or anisotropic stationary conductivity field. The solution is obtained by the finite element technique by discretizing the medium into 60 x 60 x 60 elements. Various simulations are performed for different variances of lnK and anisotropy ratios. Analytical expressions for second-order moments of the flux field, are compared with numerical results. The kinetic energy of the velocity fluctuations is also studied.

Effect and propagation of water level fluctuations in a sloping sandy beach -- Unsaturated porous media II: numerical simulation test of single harmonic wave (long run)

HAL (Le Centre pour la Communication Scientifique Directe), May 18, 2012

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Quantitative Stochastic Hydrogeology: The Heterogeneous Environment

Springer eBooks, Feb 1, 2008

... that very complex spatial patterns can be efficiently represented based on a stochastic appro... more

Comment on “Effective groundwater model parameter values: Influence of spatial variability of hydraulic conductivity, leakance, and recharge” by J. J. Gómez-Hernández and S. M. Gorelick

Water Resources Research, Aug 1, 1990

In a recent paper, G6mez-Herndndez and Gorelick [1989] studied the effective conductivity and the... more In a recent paper, G6mez-Herndndez and Gorelick [1989] studied the effective conductivity and the statistics of hydraulic heads in a bounded two-dimensional unconfined aquifer with pumping wells, assuming for the most part that hydraulic conductivity is a two-dimensional random field. The objective of this paper is to present a few constructive comments on their statistical analysis of heads and effective conductivity in the presence of pumping wells. Our comments are divided into three parts. First, we address a technical point concerning the statistics of lognormal conductivity random fields and suggest a closed form expression for the p norm which would have simplified their investigation of effective conductivity. Second, we comment on the behavior of head variance at the wells with respect to pumping rates and indicate how their Monte Carlo results relate to earlier theories. Third, we discuss the effective behavior of nonuniform flow systems and attempt to explain their effective conductivity results in connection with earlier theoretical works, plus some modest extensions of our own. We will not consider in this discussion the effects of random recharge and river leakage, which they analyzed separately. 2. THE p NORM OF LOGNORMAL RANDOM FIELDS In their paper, G6mez-Herndndez and Gorelick [1989] assumed for the most part that hydraulic conductivity K(x) is a two-dimensional random field and that the log-conductivity field In (K(x)) is itself normally distributed and stationary. The two-point covariance of In (K) was an exponentially decaying isotropic function (more on this choice later). The authors used this model to obtain via Monte-Carlo simulations the effective conductivity K e that "best fits" the simulated hydraulic heads in some least squares sense. Moreover, they chose to relate the resulting value of K e to the p norm of the random conductivity field, which they defined numerically as Kp =. (Ki) • (1) where p is a real number-1-< p-< +1. Briefly, their procedure was as follows. They plotted the bias and error variance of the hydraulic heads, where the error is the difference between the heads for randomly generated repli

John Wiley & Sons, Inc. eBooks, Jan 21, 2013

Groundwater Quality Assessment Using Water Quality Index (WQI) Approach - Gaza Coastal Aquifer as A Case Study

pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Alternative Proxies:

Alternative Proxy