Transient drawdown solution for a constant pumping test in finite two-zone confined aquifers

Abstract. The drawdown solution has been widely used to analyze pumping test data for the determination of aquifer parameters when coupled with an optimization scheme. The solution can also be used to predict the drawdown due to pumping and design the dewatering system. The drawdown solution for flow toward a finite-radius well with a skin zone in a confined aquifer of infinite extent in radial direction had been developed before. To our best knowledge, the drawdown solution in confined aquifers of finite extent so far has never before been presented in the groundwater literature. This article presents a mathematical model for describing the drawdown distribution due to a constant-flux pumping from a finite-radius well with a skin zone in confined aquifers of finite extent. The analytical solution of the model is developed by applying the methods of Laplace transforms and Bromwich contour integral. This solution can be used to investigate the effects of finite boundary and conductivity ratio on the drawdown distribution. In addition, the inverse relationship between Laplace- and time-domain variables is used to develop the large time solution which can reduce to the Thiem solution if there is no skin zone.

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Transient drawdown solution for a constant pumping test in finite two-zone confined aquifers

Hydrology and Earth System Sciences ◽

10.5194/hess-16-441-2012 ◽

2012 ◽

Vol 16 (2) ◽

pp. 441-449 ◽

Cited By ~ 10

Author(s):

C.-T. Wang ◽

H.-D. Yeh ◽

C.-S. Tsai

Keyword(s):

Large Time ◽

Pumping Test ◽

Residue Theorem ◽

Optimization Scheme ◽

Finite Radius ◽

Infinite Extent ◽

Confined Aquifers ◽

Skin Zone ◽

Finite Extent

Abstract. The drawdown solution has been widely used to analyze pumping test data for the determination of aquifer parameters when coupled with an optimization scheme. The solution can also be used to predict the drawdown due to pumping and design the dewatering system. The drawdown solution for flow toward a finite-radius well with a skin zone in a confined aquifer of infinite extent in radial direction had been developed before. To our best knowledge, the drawdown solution in confined aquifers of finite extent with a skin zone so far has never before been presented in the groundwater literature. This article presents a mathematical model for describing the drawdown distribution due to a constant-flux pumping from a finite-radius well with a skin zone in confined aquifers of finite extent. The analytical solution of the model is developed by applying the methods of Laplace transforms, Bromwich contour integral, and residue theorem. This solution can be used to investigate the effects of finite boundary and conductivity ratio on the drawdown distribution. In addition, the inverse relationship between Laplace- and time-domain variables is used to develop the large time solution which can reduce to the Thiem solution if there is no skin zone.

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Determination of aquifer parameters of finite confined aquifers from constant drawdown nonsteady type-curves

Hydrological Sciences Journal ◽

10.1080/02626669409492743 ◽

1994 ◽

Vol 39 (3) ◽

pp. 269-280 ◽

Cited By ~ 6

Author(s):

HALIL ONDER

Keyword(s):

Type Curves ◽

Aquifer Parameters ◽

Confined Aquifers

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Determination of aquifer parameters using geoelectrical sounding and pumping test data in Khanewal District, Pakistan

Open Geosciences ◽

10.1515/geo-2016-0071 ◽

2016 ◽

Vol 8 (1) ◽

Cited By ~ 17

Author(s):

Gulraiz Akhter ◽

M. Hasan

Keyword(s):

Test Data ◽

Groundwater Resources ◽

Pumping Test ◽

Vertical Electrical Sounding ◽

Analytical Relationship ◽

Pumping Tests ◽

Aquifer Parameters ◽

Surface Measurements ◽

Electrical Sounding

AbstractIn order to determine the groundwater resources and potentials of the Khanewal District of Pakistan, a geophysical method in combination with pumping test data were used. An analytical relationship between the aquifer parameters interpreted from surface geoelectrical method and pumping test was established in order to estimate aquifer parameters from surface measurements where no pumping tests exist. For the said purpose, 48 geoelectric investigations were carried out using Schlumberger vertical electrical sounding (VES). Seven of the soundings were conducted where pumping tests had been carried out at borehole sites. The vertical electrical sounding stations were interpreted, and resistivities and thickness parameters were calculated. The values of transmissivity and hydraulic conductivity were calculated using the Dar Zarrouk parameter. Transmissivity values obtained from pumping test data and the VES method range between 954 – 4263 m

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An Innovative Approach to Determination of Double-Porosity Fractured Aquifers Hydraulic Parameters Using Artificial Neural Network

10.21203/rs.3.rs-587986/v1 ◽

2021 ◽

Author(s):

Tahereh Azari ◽

Mahmoud Mohammad Rezapour Tabari

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Test Data ◽

Pumping Test ◽

Double Porosity ◽

Aquifer Parameters ◽

Aquifer Parameter ◽

Well Function ◽

Parameter Values

Abstract Accurate determination of hydraulic parameter values is the first step to the sustainable development of an aquifer. Since Theis (1935), type curve matching technique (TCMT) has been used to estimate the aquifer parameters from pumping test data. The TCMT is subjected to graphical error. To eliminate the error an Artificial Neural Network (ANN) is developed as an alternative to the conventional TCMT by modeling the Bourdet-Gringaten’s well function for the determination of the fractured double porosity aquifer parameters. The neural network model is developed in a six-step protocol based on multi-layer perceptron (MLP) networks architecture and is trained for the well function of double porosity aquifers by the back propagation method and the Levenberg-Marquardt optimization algorithm. By applying the principal component analysis on the training input data and through a trial-and-error procedure the optimum structure of the network is fixed with the topology of [3×6×3]. The replicative, predictive and structural validity of the developed network are evaluated with synthetic and real field data. The developed network provides an automatic and fast procedure for the double porosity aquifer parameter determination that eliminates graphical errors inherent in the conventional TCMT. The network receives pumping test data and provides the user with the aquifer parameter values.

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A Graphical Method for Storage Coefficient Determination from Quasi-Steady State Flow Data

Hydrology Research ◽

10.2166/nh.1996.0008 ◽

1996 ◽

Vol 27 (4) ◽

pp. 247-254 ◽

Cited By ~ 2

Author(s):

Zekâi Şen

Keyword(s):

Steady State ◽

Graphical Method ◽

Pumping Test ◽

Quasi Steady State ◽

Flow Data ◽

Steady State Flow ◽

Storage Coefficient ◽

State Flow ◽

Aquifer Test

A simple, approximate but practical graphical method is proposed for estimating the storage coefficient independently from the transmissivity value, provided that quasi-steady state flow data are available from a pumping test. In the past, quasi-steady state flow distance-drawdown data have been used for the determination of transmissivity only. The method is applicable to confined and leaky aquifers. The application of the method has been performed for various aquifer test data available in the groundwater literature. The results are within the practical limits of approximation compared with the unsteady state flow solutions.

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