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Jiu Jimmy Jiao - One of the best experts on this subject based on the ideXlab platform.
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Analytical Solution of Tidal Loading Effect in a Submarine Leaky Confined Aquifer System
Geofluids, 2019Co-Authors: Zongzhong Song, Jiu Jimmy Jiao, Chunmiao Zheng, Qian Ma, Hailong Li, Shaohong LiAbstract:Although there are many existing analytical studies of tidal groundwater level fluctuations in coastal Aquifer systems, few of them focus on an offshore submarine Aquifer. Here, we consider tidal groundwater head fluctuations in a submarine leaky Confined Aquifer overlain by a semipermeable seabed. Both the seabed and the Confined Aquifer are assumed to extend horizontally infinitely. A one-dimensional mathematical model is established to describe the problem, and the analytical solution is derived. The impacts of the tidal loading efficiency, hydraulic conductivity and elastic storage of the semipermeable layer and Aquifer on the groundwater head fluctuations in the Aquifer system are analyzed and discussed. Solution analyses indicated that tidal loading effects tend to enhance the amplitude of the tidal groundwater fluctuation in the Confined Aquifer system and to reduce the phase shift between the groundwater head and the sea tide fluctuations.
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analytical studies of groundwater head fluctuation in a coastal Confined Aquifer overlain by a semi permeable layer with storage
Advances in Water Resources, 2001Co-Authors: Hailong Li, Jiu Jimmy JiaoAbstract:Abstract Analytical studies are carried out to investigate groundwater-head changes in a coastal Aquifer system in response to tidal fluctuations. The system consists of an unConfined Aquifer, a semi-Confined Aquifer and a semi-permeable confining unit between them. An exact analytical solution is derived to investigate the influences of both leakage and storage of the semi-permeable layer on the tide-induced groundwater-head fluctuation in the semi-Confined Aquifer. This solution is a generalization of the solution obtained by Jiao and Tang (Water Resource Research 35 (1999) 747–751) which ignored the storage of the semi-confining unit. The analytical solution indicates that both storage and leakage of the semi-permeable layer play an important role in the groundwater-head fluctuation in the Confined Aquifer. While leakage is generally more important than storage, the impact of storage on groundwater-head fluctuations changes with leakage. With the increase of leakage the fluctuation of groundwater-head in the Confined Aquifer will be controlled mainly by leakage. The study also demonstrates that the influence of storativity of the semi-permeable layer on groundwater-head fluctuation is negligible only when the storativity of the semi-permeable layer is comparable to or smaller than that of the Confined Aquifer. However, for Aquifer systems with semi-permeable layer composed of thick, soft sedimentary materials, the storativity of the semi-permeable layer is usually much greater than that of the Aquifer and its influence should be considered.
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tide induced groundwater fluctuation in a coastal leaky Confined Aquifer system extending under the sea
Water Resources Research, 2001Co-Authors: Hailong Li, Jiu Jimmy JiaoAbstract:This paper presents the analytical solution of groundwater response to tidal fluctuation in a coastal multilayer Aquifer system consisting of a leaky Confined Aquifer, a semipermeable layer, and an unConfined Aquifer. The semipermeable layer, or the roof of the leaky Confined Aquifer, extends under the sea. Comparisons are made with solutions derived previously, which considered only a single Aquifer, zero extension of the roof, or infinite roof length, and demonstrate that the previous solutions are special cases of the solution presented here. A hypothetical example is used to discuss the impact of the dimensionless roof length, dimensionless leakage, and tidal efficiency on the groundwater level fluctuations in the inland part of the Confined Aquifer. The fluctuation decreases significantly with the roof length when the roof length is small but is insensitive to the change of roof length when the roof length is greater than a threshold. The impacts of leakage from the offshore and inland portions of the confining unit are different. Leakage from the offshore portion tends to increase the fluctuation of the groundwater level, while leakage from the inland portion tends to decrease the fluctuation. The fluctuation increases as the tidal efficiency increases. This fact is significant only when the roof length is great and leakage is small.
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A two-dimensional analytical solution for groundwater flow in a leaky Confined Aquifer system near open tidal water
Hydrological Processes, 2001Co-Authors: Zhonghua Tang, Jiu Jimmy JiaoAbstract:Groundwater in coastal areas is commonly disturbed by tidal fluctuations. A two-dimensional analytical solution is derived to describe the groundwater fluctuation in a leaky Confined Aquifer system near open tidal water under the assumption that the groundwater head in the Confined Aquifer fluctuates in response to sea tide whereas that of the overlying unConfined Aquifer remains constant. The analytical solution presented here is an extension of the solution by Sun for two-dimensional groundwater flow in a Confined Aquifer and the solution by Jiao and Tang for onedimensional groundwater flow in a leaky Confined Aquifer. The analytical solution is compared with a two-dimensional finite difference solution. On the basis of the analytical solution, the groundwater head distribution in a leaky Confined Aquifer in response to tidal boundaries is examined and the influence of leakage on groundwater fluctuation is discussed. Copyright 2001 John Wiley & Sons, Ltd.
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An analytical solution of groundwater response to tidal fluctuation in a leaky Confined Aquifer
Water Resources Research, 1999Co-Authors: Jiu Jimmy Jiao, Zhonghua TangAbstract:An analytical solution is derived to investigate the influence of leakage on tidal response in a coastal leaky Confined Aquifer system. The analytical solution developed here is more general than the traditional solution obtained by Ferris [1951], which can be regarded as a special case of the solution presented in this paper. This solution is based on a conceptual model under the assumption that the groundwater level in the Confined Aquifer fluctuates in response to sea tide while that of the overlying unConfined Aquifer remains constant. This conceptual model is supported by numerous field studies by previous researchers which have demonstrated that the tidal response in an unConfined Aquifer may be negligible compared to that in a Confined Aquifer. The leakage has a significant impact on the tidal behavior of the Confined Aquifer. Hypothetical studies indicate that both tidal amplitude of groundwater head in the Aquifer and the distance over which the Aquifer can be disturbed by the sea tide will be considerably reduced because of the existence of leakage. This analytical solution is used to investigate the tidal and piezometer data at the Chek Lap Kok airport, Hong Kong Special Administrative Region, People's Republic of China.
Mostafa A. M. Abdeen - One of the best experts on this subject based on the ideXlab platform.
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predicting the impact of subsurface heterogeneous hydraulic conductivity on the stochastic behavior of well draw down in a Confined Aquifer using artificial neural networks
Journal of Mechanical Science and Technology, 2005Co-Authors: Alaa El-din Abdin, Mostafa A. M. AbdeenAbstract:Groundwater flow and behavior have to be investigated based on heterogeneous subsurface formation since the homogeneity assumption of this formation is not valid. Over the past twenty years, stochastic approach and Monte Carlo technique have been utilized very efficiently to understand the groundwater flow behavior. However, these techniques require lots of computational and numerical efforts according to the various researchers’ comments. Therefore, utilizing new techniques with much less computational efforts such as Artificial Neural Network (ANN) in the prediction of the stochastic behavior for the groundwater based on heterogeneous subsurface formation is highly appreciated. The current paper introduces the ANN technique to investigate and predict the stochastic behavior of a well draw down in a Confined Aquifer based on subsurface heterogeneous hydraulic conductivity. Several ANN models are developed in this research to predict the unsteady two dimensional well draw down and its stochastic characteristics in a Confined Aquifer. The results of this study showed that ANN method with less computational efforts was very efficiently capable of simulating and predicting the stochastic behavior of the well draw down resulted from the continuous constant pumping in the middle of a Confined Aquifer with subsurface heterogeneous hydraulic conductivity.
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Predicting the impact of subsurface heterogeneous hydraulic conductivity on the stochastic behavior of well draw down in a Confined Aquifer using artificial neural networks
Journal of Mechanical Science and Technology, 2005Co-Authors: Alaa El-din Abdin, Mostafa A. M. AbdeenAbstract:Groundwater flow and behavior have to be investigated based on heterogeneous subsurface formation since the homogeneity assumption of this formation is not valid. Over the past twenty years, stochastic approach and Monte Carlo technique have been utilized very efficiently to understand the groundwater flow behavior. However, these technique require lots of computational and numerical efforts according to the various researchers' comments. Therefore, utilizing new techniques with much less computational efforts such as Artificial Neural Network (ANN) in the prediction of the stochastic behavior for the groundwater based on heterogeneous subsurface formation is highly appreciated. The current paper introduces the ANN technique to investigate and predict the stochastic behavior of a well draw down in a Confined Aquifer based on subsurface heterogeneous hydraulic conductivity. Several ANN models are developed in this research to prediet the unsteady two dimensional well draw down and its stochastic characteristics in a Confined Aquifer. The results of this study showed that ANN method with less computational efforts was very efficiently capable of simulating and predicting the stochastic behavior of the well draw down resulted from the continuous constant pumping in the middle of a Confined Aquifer with subsurface heterogeneous hydraulic conductivity.
Alaa El-din Abdin - One of the best experts on this subject based on the ideXlab platform.
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predicting the impact of subsurface heterogeneous hydraulic conductivity on the stochastic behavior of well draw down in a Confined Aquifer using artificial neural networks
Journal of Mechanical Science and Technology, 2005Co-Authors: Alaa El-din Abdin, Mostafa A. M. AbdeenAbstract:Groundwater flow and behavior have to be investigated based on heterogeneous subsurface formation since the homogeneity assumption of this formation is not valid. Over the past twenty years, stochastic approach and Monte Carlo technique have been utilized very efficiently to understand the groundwater flow behavior. However, these techniques require lots of computational and numerical efforts according to the various researchers’ comments. Therefore, utilizing new techniques with much less computational efforts such as Artificial Neural Network (ANN) in the prediction of the stochastic behavior for the groundwater based on heterogeneous subsurface formation is highly appreciated. The current paper introduces the ANN technique to investigate and predict the stochastic behavior of a well draw down in a Confined Aquifer based on subsurface heterogeneous hydraulic conductivity. Several ANN models are developed in this research to predict the unsteady two dimensional well draw down and its stochastic characteristics in a Confined Aquifer. The results of this study showed that ANN method with less computational efforts was very efficiently capable of simulating and predicting the stochastic behavior of the well draw down resulted from the continuous constant pumping in the middle of a Confined Aquifer with subsurface heterogeneous hydraulic conductivity.
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Predicting the impact of subsurface heterogeneous hydraulic conductivity on the stochastic behavior of well draw down in a Confined Aquifer using artificial neural networks
Journal of Mechanical Science and Technology, 2005Co-Authors: Alaa El-din Abdin, Mostafa A. M. AbdeenAbstract:Groundwater flow and behavior have to be investigated based on heterogeneous subsurface formation since the homogeneity assumption of this formation is not valid. Over the past twenty years, stochastic approach and Monte Carlo technique have been utilized very efficiently to understand the groundwater flow behavior. However, these technique require lots of computational and numerical efforts according to the various researchers' comments. Therefore, utilizing new techniques with much less computational efforts such as Artificial Neural Network (ANN) in the prediction of the stochastic behavior for the groundwater based on heterogeneous subsurface formation is highly appreciated. The current paper introduces the ANN technique to investigate and predict the stochastic behavior of a well draw down in a Confined Aquifer based on subsurface heterogeneous hydraulic conductivity. Several ANN models are developed in this research to prediet the unsteady two dimensional well draw down and its stochastic characteristics in a Confined Aquifer. The results of this study showed that ANN method with less computational efforts was very efficiently capable of simulating and predicting the stochastic behavior of the well draw down resulted from the continuous constant pumping in the middle of a Confined Aquifer with subsurface heterogeneous hydraulic conductivity.
Hund-der Yeh - One of the best experts on this subject based on the ideXlab platform.
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radial groundwater flow to a finite diameter well in a leaky Confined Aquifer with a finite thickness skin
Hydrological Processes, 2009Co-Authors: Shaw Yang Yang, Hund-der YehAbstract:A mathematical model that describes the drawdown due to constant pumpage from a finite radius well in a two-zone leaky Confined Aquifer system is presented. The Aquifer system is overlain by an aquitard and underlain by an impermeable formation. A skin zone of constant thickness exists around the wellbore. A general solution to a two-zone leaky Confined Aquifer system in Laplace domain is developed and inverted numerically to the time-domain solution using the modified Crump (1976) algorithm. The results show that the drawdown distribution is significantly influenced by the properties and thickness of the skin zone and aquitard. The sensitivity analyses of parameters of the Aquifer and aquitard are performed to illustrate their effects on drawdowns in a two-zone leaky Confined Aquifer system. For the negative-skin case, the drawdown is very sensitive to the relative change in the formation transmissivity. For the positive-skin case, the drawdown is also sensitive to the relative changes in the skin thickness, and both the skin and formation transmissivities over the entire pumping period and the well radius and formation storage coefficient at early pumping time. Copyright © 2009 John Wiley & Sons, Ltd.
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An analytical solution for the head distribution in a tidal leaky Confined Aquifer extending an infinite distance under the sea
Advances in Water Resources, 2007Co-Authors: Mo-hsiung Chuang, Hund-der YehAbstract:Abstract A mathematical model is developed to investigate the effects of tidal fluctuations and leakage on the groundwater head of leaky Confined Aquifer extending an infinite distance under the sea. The leakages of the offshore and inland aquitards are two dominant factors controlling the groundwater fluctuation. The tidal influence distance from the coast decreases significantly with the dimensionless leakage of the inland aquitard ( u i ). The fluctuation of groundwater level in the inland part of the leaky Confined Aquifer increases significantly with the dimensionless leakage of the offshore aquitard ( u o ). The influence of the tidal propagation parameter of an unConfined Aquifer on the head fluctuation of the leaky Confined Aquifer is comparatively conspicuous when u i is large and u o is small. In other words, ignoring water table fluctuation of the unConfined Aquifer will give large errors in predicting the fluctuation, time lag, and tidal influence distance of the leaky Confined Aquifer for large u i and small u o . On the contrary, the influence of the tidal propagation parameter of a leaky Confined Aquifer on the head fluctuation of the leaky Confined Aquifer is large for large u o and small u i .
Hailong Li - One of the best experts on this subject based on the ideXlab platform.
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Analytical Solution of Tidal Loading Effect in a Submarine Leaky Confined Aquifer System
Geofluids, 2019Co-Authors: Zongzhong Song, Jiu Jimmy Jiao, Chunmiao Zheng, Qian Ma, Hailong Li, Shaohong LiAbstract:Although there are many existing analytical studies of tidal groundwater level fluctuations in coastal Aquifer systems, few of them focus on an offshore submarine Aquifer. Here, we consider tidal groundwater head fluctuations in a submarine leaky Confined Aquifer overlain by a semipermeable seabed. Both the seabed and the Confined Aquifer are assumed to extend horizontally infinitely. A one-dimensional mathematical model is established to describe the problem, and the analytical solution is derived. The impacts of the tidal loading efficiency, hydraulic conductivity and elastic storage of the semipermeable layer and Aquifer on the groundwater head fluctuations in the Aquifer system are analyzed and discussed. Solution analyses indicated that tidal loading effects tend to enhance the amplitude of the tidal groundwater fluctuation in the Confined Aquifer system and to reduce the phase shift between the groundwater head and the sea tide fluctuations.
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analytical studies of groundwater head fluctuation in a coastal Confined Aquifer overlain by a semi permeable layer with storage
Advances in Water Resources, 2001Co-Authors: Hailong Li, Jiu Jimmy JiaoAbstract:Abstract Analytical studies are carried out to investigate groundwater-head changes in a coastal Aquifer system in response to tidal fluctuations. The system consists of an unConfined Aquifer, a semi-Confined Aquifer and a semi-permeable confining unit between them. An exact analytical solution is derived to investigate the influences of both leakage and storage of the semi-permeable layer on the tide-induced groundwater-head fluctuation in the semi-Confined Aquifer. This solution is a generalization of the solution obtained by Jiao and Tang (Water Resource Research 35 (1999) 747–751) which ignored the storage of the semi-confining unit. The analytical solution indicates that both storage and leakage of the semi-permeable layer play an important role in the groundwater-head fluctuation in the Confined Aquifer. While leakage is generally more important than storage, the impact of storage on groundwater-head fluctuations changes with leakage. With the increase of leakage the fluctuation of groundwater-head in the Confined Aquifer will be controlled mainly by leakage. The study also demonstrates that the influence of storativity of the semi-permeable layer on groundwater-head fluctuation is negligible only when the storativity of the semi-permeable layer is comparable to or smaller than that of the Confined Aquifer. However, for Aquifer systems with semi-permeable layer composed of thick, soft sedimentary materials, the storativity of the semi-permeable layer is usually much greater than that of the Aquifer and its influence should be considered.
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tide induced groundwater fluctuation in a coastal leaky Confined Aquifer system extending under the sea
Water Resources Research, 2001Co-Authors: Hailong Li, Jiu Jimmy JiaoAbstract:This paper presents the analytical solution of groundwater response to tidal fluctuation in a coastal multilayer Aquifer system consisting of a leaky Confined Aquifer, a semipermeable layer, and an unConfined Aquifer. The semipermeable layer, or the roof of the leaky Confined Aquifer, extends under the sea. Comparisons are made with solutions derived previously, which considered only a single Aquifer, zero extension of the roof, or infinite roof length, and demonstrate that the previous solutions are special cases of the solution presented here. A hypothetical example is used to discuss the impact of the dimensionless roof length, dimensionless leakage, and tidal efficiency on the groundwater level fluctuations in the inland part of the Confined Aquifer. The fluctuation decreases significantly with the roof length when the roof length is small but is insensitive to the change of roof length when the roof length is greater than a threshold. The impacts of leakage from the offshore and inland portions of the confining unit are different. Leakage from the offshore portion tends to increase the fluctuation of the groundwater level, while leakage from the inland portion tends to decrease the fluctuation. The fluctuation increases as the tidal efficiency increases. This fact is significant only when the roof length is great and leakage is small.
