The Henry problem: New semianalytical solution for velocity-dependent dispersion

2016 ◽  
Vol 52 (9) ◽  
pp. 7382-7407 ◽  
Author(s):  
Marwan Fahs ◽  
Behzad Ataie-Ashtiani ◽  
Anis Younes ◽  
Craig T. Simmons ◽  
Philippe Ackerer
Keyword(s):  
Henry Problem

scholarly journals Fourier series solution for an anisotropic and layered configuration of the dispersive Henry Problem

2018 ◽  
Vol 54 ◽  
pp. 00014
Author(s):  
B. Koohbor ◽  
M. Fahs ◽  
B. Belfort ◽  
B. Ataie-Ashtiani ◽  
C. T. Simmons
Keyword(s):  
Fourier Series ◽  
Diffusion Coefficients ◽  
Series Solution ◽  
Numerical Solutions ◽  
Numerical Models ◽  
Salt Transport ◽  
Spectral Space ◽  
Finite Element Code ◽  
Henry Problem ◽  
Lower Diffusion

Henry Problem (HP) still plays an important role in benchmarking numerical models of seawater intrusion (SWI) as well as being applied to practical and managerial purposes. The popularity of this problem is due to having a closed-form semi-analytical (SA) solution. The early SA solutions obtained for HP were limited to extensive assumptions that restrict its application in practical works. Several further studies expended the generality of the solution by assuming lower diffusion coefficients or including velocity-dependent dispersion in the results. However, all these studies are limited to homogeneous and isotropic domains. The present work made an attempt to improve the reality of the SA solution obtained for dispersive HP by considering anisotropic and stratified heterogeneous coastal aquifers. The solution is obtained by defining Fourier series for both stream function and salt concentration, applying a Galerkin treatment using the Fourier modes as trial functions and solving the flow and the salt transport equations simultaneously in the spectral space. In order to include stratified heterogeneity, a special depth-hydraulic conductivity model is applied that can be solved analytically without significant mathematical complexity. Several examples are proposed and studied. The results show excellent agreement between the SA and numerical solutions obtained with an in-house advanced finite element code.

scholarly journals A New Normalized Groundwater Age-Based Index for Quantitative Evaluation of the Vulnerability to Seawater Intrusion in Coastal Aquifers: Implications for Management and Risk Assessments

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2496
Author(s):  
Mohammed Adil Sbai ◽  
Abdelkader Larabi ◽  
Marwan Fahs ◽  
Joanna Doummar
Keyword(s):  
Steady State ◽  
Seawater Intrusion ◽  
Coastal Aquifers ◽  
Groundwater Age ◽  
Groundwater Resources ◽  
Age Distribution ◽  
Flow Simulation ◽  
Risk Assessments ◽  
Henry Problem ◽  
Variable Density Flow

The vulnerability of coastal aquifers to seawater intrusion has been largely relying on data-driven indexing approaches despite their shortcomings to depict the complex processes of groundwater flow and mass transport under variable velocity conditions. This paper introduces a modelling-based alternative technique relying on a normalized saltwater age vulnerability index post-processed from results of a variable density flow simulation. This distributed index is obtained from the steady-state distribution of the salinity and a restriction of the mean groundwater age to a mean saltwater age distribution. This approach provides a novel way to shift from the concentration space into a vulnerability assessment space to evaluate the threats to coastal aquifers. The method requires only a sequential numerical solution of two steady state sets of equations. Several variants of the hypothetical Henry problem and a case study in Lebanon are selected for demonstration. Results highlight this approach ability to rank, compare, and validate different scenarios for coastal water resources management. A novel concept of zero-vulnerability line/surface delineating the coastal area threatened by seawater intrusion has shown to be relevant for optimal management of coastal aquifers and risk assessments. Hence, this work provides a new tool to sustainably manage and protect coastal groundwater resources.

Numerical analysis of the effects of changing hydraulic parameters on saltwater intrusion in coastal aquifers

2016 ◽  
Vol 33 (8) ◽  
pp. 2546-2564 ◽  
Author(s):  
Ismail Abd-Elaty ◽  
Hany Farhat Abd Elhamid ◽  
Akbar Javadi
Keyword(s):  
Hydraulic Conductivity ◽  
Numerical Model ◽  
Coastal Aquifers ◽  
Saltwater Intrusion ◽  
Control Method ◽  
Hydraulic Parameters ◽  
Content Type ◽  
Henry Problem ◽  
The Impact ◽  
Biscayne Aquifer

Purpose The purpose of this paper is to develop and validate a numerical model to study the effect of changing hydraulic parameters on saltwater intrusion in coastal aquifers. Design/methodology/approach The numerical model SEAWAT is validated and applied to a hypothetical case (Henry problem) and a real case study (Biscayne aquifer, Florida, USA) for different values of hydraulic parameters including; hydraulic conductivity, porosity, dispersion, diffusion, fluid density and solute concentration. The dimensional analysis technique is used to correlate these parameters with the intrusion length. Findings The results show that the hydraulic parameters have a clear effect on saltwater intrusion as they increase the intrusion in some cases and decrease it in some other cases. The results indicate that changing hydraulic parameters may be used as a control method to protect coastal aquifers from saltwater intrusion. Practical implications The results of the application of the model to the Biscayne aquifer in Florida showed that the intrusion can be reduced to 50 percent when the hydraulic conductivity is reduced to 50 percent. Decreasing hydraulic conductivity by injecting some relatively cheap materials such as bentonite can help to reduce the intrusion of saltwater. So the saltwater intrusion can be reduced with relatively low cost through changing some hydraulic parameters. Originality/value A relationship to calculate intrusion length in coastal aquifer is developed and the impact of different hydraulic parameters on saltwater intrusion is highlighted. Control of saltwater intrusion using relatively cheap method is presented.

scholarly journals Anisotropic dispersive Henry problem

2007 ◽  
Vol 30 (4) ◽  
pp. 913-926 ◽  
Author(s):  
Elena Abarca ◽  
Jesús Carrera ◽  
Xavier Sánchez-Vila ◽  
Marco Dentz
Keyword(s):  
Henry Problem

scholarly journals A Generalized Semi-Analytical Solution for the Dispersive Henry Problem: Effect of Stratification and Anisotropy on Seawater Intrusion

Water ◽  
2018 ◽  
Vol 10 (2) ◽  
pp. 230 ◽  
Author(s):  
Marwan Fahs ◽  
Behshad Koohbor ◽  
Benjamin Belfort ◽  
Behzad Ataie-Ashtiani ◽  
Craig Simmons ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Seawater Intrusion ◽  
Henry Problem
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