scholarly journals A generalized analytical solution of groundwater head response to dual tide in a multilayered island leaky aquifer system

2021 ◽  
Author(s):  
Zhi-Xue Z'hao ◽  
Yonghong Hao ◽  
Tongke Wang ◽  
T J Yeh ◽  
Ming Zhang
Keyword(s):  
Analytical Solution ◽  
Separation Of Variables ◽  
Unconfined Aquifer ◽  
Field Investigation ◽  
Bottom Part ◽  
Factors Affecting ◽  
Aquifer System ◽  
Tidal Propagation ◽  
Groundwater Head ◽  
Aquifer Systems

The hydraulic properties of coastal aquifer systems are relevant to various hydrogeological, hydro-ecological and engineering problems. This study presents an analytical solution for predicting groundwater head fluctuations induced by dual-tide in multilayered island aquifer systems, consisting of an unconfined aquifer on the top and any number of leaky aquifers below. The solution was derived via the methods of matrix differential calculus and separation of variables. It is more general than any existing analytical solutions for the tidal pressure propagation since the new solution can consider multilayered aquifer systems along with the effects of leakage and aquifer length. Using this solution, we illustrated potential errors that may occur due to neglecting one or more vital factors affecting groundwater fluctuations. Besides, we articulated the groundwater response to the dual-tide in complex coastal aquifers. Considering that some thin semipermeable layers may be ignored in practical field investigation, we also demonstrated the effects due to simplification of aquifer layers. The results showed that with the increase in the number of overlapped leaky layers, the tidal propagation in the bottom part of multilayered aquifer system approaches that in a single confined aquifer with the same transmissivity and storage.

scholarly journals Analytical Solution of Tidal Loading Effect in a Submarine Leaky Confined Aquifer System

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Zongzhong Song ◽  
Hailong Li ◽  
Qian Ma ◽  
Chunmiao Zheng ◽  
Jiu Jimmy Jiao ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Confined Aquifer ◽  
One Dimensional ◽  
Aquifer System ◽  
Groundwater Level Fluctuations ◽  
Groundwater Head ◽  
Aquifer Systems ◽  
Groundwater Fluctuation ◽  
Loading Effects ◽  
Tidal Loading

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.

The Distribution of Volatile Organics in a Leachate Plume, Gloucester, Ontario

1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman
Keyword(s):  
Organic Contaminants ◽  
Source Area ◽  
Unconfined Aquifer ◽  
High Concentration ◽  
Organic Contamination ◽  
Aquifer System ◽  
Aquifer Systems ◽  
Volatile Organic ◽  
Volatile Organic Contaminants ◽  
Aquifer Sediments

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.

scholarly journals Analytical assessment of subsidence due to Aquifer Storage and Recovery (ASR) applications to multi-aquifer systems

2000 ◽  
Vol 21 ◽  
Author(s):  
J. Li
Keyword(s):  
Analytical Solution ◽  
Land Subsidence ◽  
Potential Risk ◽  
Aquifer Storage And Recovery ◽  
One Dimensional ◽  
Aquifer System ◽  
Aquifer Storage ◽  
Aquifer Systems ◽  
The One ◽  
Development And Management

The present paper emphasises concerns of land subsidence or compression of clay confining beds caused by periodic withdrawal and injection of water from or into the adjacent aquifers. An analytical solution for a one-dimensional case based on a sandwich model is found so that analysis of potential risk of aquifer system deformation due to the technology of Aquifer Storage and Recovery (ASR) can be conducted. A governing equation expressed directly in terms of displacement is employed to describe the one-dimensional subsidence. For simplicity, saturated aquifer systems are assumed to behave like poroelastic material. A cyclic loading function with a triangle pattern is assumed at boundaries to simulate effective stress induced by changes in hydraulic head at boundaries. The both compression and swelling of clay due to the periodic and linear loads at the boundaries are considered in this model. The two aquifers (one above the confining bed and the other beneath) can be pumped independently of each other. The results from the analytical solution are applied to estimate and predict potential risk of land subsidence due to ASR activity and to provide a first-estimate type of guideline for city or regional development and management of water resources.

scholarly journals Groundwater fluctuations in heterogeneous coastal leaky aquifer systems

2010 ◽  
Vol 14 (10) ◽  
pp. 1819-1826 ◽  
Author(s):  
M.-H. Chuang ◽  
C.-S. Huang ◽  
G.-H. Li ◽  
H.-D. Yeh
Keyword(s):  
Phase Shift ◽  
Unconfined Aquifer ◽  
One Dimensional ◽  
Aquifer System ◽  
The Past ◽  
Depositional Processes ◽  
Aquifer Systems ◽  
Infinite Extent ◽  
Leaky Aquifer ◽  
Finite Extent

Abstract. In the past, the coastal leaky aquifer system, including two aquifers and an aquitard between them, was commonly assumed to be homogeneous and of infinite extent in the horizontal direction. The leaky aquifer system may however be heterogeneous and of finite extent due to variations in depositional and post depositional processes. In this paper, the leaky aquifer system is divided into several horizontal regions for the heterogeneous aquitard and underlying aquifer. A one-dimensional analytical model is developed for describing the head fluctuation in such a heterogeneous leaky aquifer system. The hydraulic head of the upper unconfined aquifer is assumed constant. It is found that both the length and location of the discontinuous aquitards presented in the coastal area have significant effects on the amplitude and phase shift of the head fluctuation in the lower aquifer. In addition, the influence of the formation heterogeneity on the spatial head distribution is also investigated.

scholarly journals Groundwater fluctuations in heterogeneous coastal leaky aquifer systems

2010 ◽  
Vol 7 (4) ◽  
pp. 4473-4499 ◽  
Author(s):  
M.-H. Chuang ◽  
C.-S. Huang ◽  
G.-H. Li ◽  
H.-D. Yeh
Keyword(s):  
Unconfined Aquifer ◽  
Confined Aquifer ◽  
Aquifer System ◽  
Heterogeneous Aquifer ◽  
The Past ◽  
Depositional Processes ◽  
Aquifer Systems ◽  
Infinite Extent ◽  
Leaky Aquifer ◽  
Finite Extent

Abstract. In the past, the coastal leaky aquifer system, including an unconfined aquifer on the top, a confined aquifer at the bottom, and an aquitard in between, was commonly assumed to be homogeneous and of an infinite extent in the horizontal direction. The leaky aquifer system may however be nonhomogeneous and of a finite extent due to variations in depositional and post depositional processes. Thus, in the paper, the leaky aquifer system is divided into several horizontal regions for simulating the heterogeneity involved in both the confined aquifer and aquitard. A one-dimensional analytical model is developed for describing the head fluctuation in such a heterogeneous leaky aquifer system. The head of the upper unconfined aquifer is assumed to remain constant. It is found that both the length and location of the discontinuous aquitards presented in the coastal area have significant effects on the amplitude and phase shift of the head fluctuation in the confined aquifer. In addition, the influences of both the heterogeneous aquifer and aquitard on the spatial head distribution are investigated.

Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

2018 ◽  
Vol 7 (4) ◽  
pp. 191
Author(s):  
Sherwan Sh. Qurtas
Keyword(s):  
Unconfined Aquifer ◽  
Middle Part ◽  
Water Levels ◽  
Specific Yield ◽  
Aquifer System ◽  
Groundwater Levels ◽  
Monitoring Wells ◽  
Water Table Fluctuation Method ◽  
Recharge Estimation ◽  
Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

An analytical solution of a two-dimensional temperature field in a hollow cylinder under a time periodic boundary condition using Fourier series

2009 ◽  
Vol 223 (8) ◽  
pp. 1889-1901 ◽  
Author(s):  
G Atefi ◽  
M A Abdous ◽  
A Ganjehkaviri ◽  
N Moalemi
Keyword(s):  
Boundary Condition ◽  
Temperature Field ◽  
Fourier Series ◽  
Temperature Distribution ◽  
Analytical Solution ◽  
Hollow Cylinder ◽  
Periodic Boundary Condition ◽  
Periodic Boundary ◽  
Separation Of Variables ◽  
Two Dimensional

The objective of this article is to derive an analytical solution for a two-dimensional temperature field in a hollow cylinder, which is subjected to a periodic boundary condition at the outer surface, while the inner surface is insulated. The material is assumed to be homogeneous and isotropic with time-independent thermal properties. Because of the time-dependent term in the boundary condition, Duhamel's theorem is used to solve the problem for a periodic boundary condition. The periodic boundary condition is decomposed using the Fourier series. This condition is simulated with harmonic oscillation; however, there are some differences with the real situation. To solve this problem, first of all the boundary condition is assumed to be steady. By applying the method of separation of variables, the temperature distribution in a hollow cylinder can be obtained. Then, the boundary condition is assumed to be transient. In both these cases, the solutions are separately calculated. By using Duhamel's theorem, the temperature distribution field in a hollow cylinder is obtained. The final result is plotted with respect to the Biot and Fourier numbers. There is good agreement between the results of the proposed method and those reported by others for this geometry under a simple harmonic boundary condition.

The Migration Behaviour of Transuranium Elements in Gorleben Aquifer Systems: Colloid Generation and Retention Process

1988 ◽  
Vol 127 ◽  
Author(s):  
J. I. Kim ◽  
G. Buckau ◽  
H. Rommel ◽  
B. Sohnius
Keyword(s):  
Migration Process ◽  
Transuranium Elements ◽  
Aquifer System ◽  
Migration Behaviour ◽  
Aquifer Systems ◽  
Migration Study

ABSTRACTThe colloid generation as a part of the migration process of trans-uranic ions has been studied in the Gorlben aquifer system. From the migration study for the Gorleben repository site, typical examples are selected to demonstrate the influence of colloids. The quantification of colloid generation and its influence on the dissolution and geochemical sorption of transuranium elements are discussed.

The implication of tectonic structures compartment in the hydrochemical distribution in the Merapi unconfined aquifer system

2021 ◽  
Vol 12 (2) ◽  
pp. 116
Author(s):  
Herry Riswandi ◽  
Emi Sukiyah ◽  
Boy Yoseph C.S.S. Syah Alam ◽  
Mohamad Sapari Dwi Hadian
Keyword(s):  
Unconfined Aquifer ◽  
Tectonic Structures ◽  
Aquifer System
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