scholarly journals Simulated Aquifer Heterogeneity Leads to Enhanced Attenuation and Multiple Retention Processes of Zinc

2021 ◽  
Vol 55 (5) ◽  
pp. 2939-2948
Author(s):  
Maya Engel ◽  
Kristin Boye ◽  
Vincent Noël ◽  
Tristan Babey ◽  
John R. Bargar ◽  
...  
Keyword(s):  
Aquifer Heterogeneity

scholarly journals Depth–Sequential Investigation of Major Ions, δ18o, δ2h and δ13C in Fractured Aquifers of the St. Lawrence Lowlands (Quebec, Canada) Using Passive Samplers

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1806
Author(s):  
Guillaume Meyzonnat ◽  
Florent Barbecot ◽  
José Corcho Alvarado ◽  
Daniele Luigi Pinti ◽  
Jean-Marc Lauzon ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Major Ions ◽  
Anthropogenic Activities ◽  
Carbon Sources ◽  
Passive Samplers ◽  
Flow Paths ◽  
Aquifer Heterogeneity ◽  
Fractured Aquifers ◽  
Fractured Carbonate ◽  
Observation Wells

General and isotopic geochemistry of groundwater is an essential tool to decipher hydrogeological contexts and flow paths. Different hydrogeochemical patterns may result from the inherent physical aquifer heterogeneity, which may go unnoticed without detailed investigations gathered from multilevel or multiple observation wells. An alternative to overcome the frequent unavailability of multiple wellbores at sites is to perform a detailed investigation on the single wellbore available. In this perspective, the aim of this study is to use passive samplers to sequentially collect groundwater at depths in long–screened wellbores. Such investigation is carried out for major ions and stable isotopes compositions (δ2H, δ18O, δ13C) at ten sites in the context of fractured carbonate aquifers of the St. Lawrence Lowlands (Quebec, Canada). The information gathered from the calco–carbonic system, major ions and stable isotopes report poorly stratified and evolved groundwater bodies. Contribution of water impacted by anthropogenic activities, such as road salts pollution and carbon sources from C4 vegetation, when they occur, are even observed at the greatest depths. Such observations suggest quick flow paths and efficient mixing conditions, which leads to significant contributions of contemporary groundwater bodies in the fractured aquifers investigated down to depths of about 100 m. Although physical aquifer investigation reported few and heterogeneously distributed fractures per wellbore, hydrogeochemical findings point to at overall well interconnected fracture networks in the aquifer and high vulnerability of groundwater, even at significant depths.

Effects of aquifer heterogeneity and reaction mechanism uncertainty on a reactive barrier

1999 ◽  
Vol 68 (1-2) ◽  
pp. 73-96 ◽  
Author(s):  
Gerald R. Eykholt ◽  
Carl R. Elder ◽  
Craig H. Benson
Keyword(s):  
Reaction Mechanism ◽  
Aquifer Heterogeneity ◽  
Reactive Barrier

Predicting Groundwater Flow and Solute Transport in the Heterogeneous Aquifer Sandbox Using Different Parameter Estimation Methods

2021 ◽  
Author(s):  
Liqun Jiang ◽  
Ronglin Sun ◽  
Xing Liang
Keyword(s):  
Steady State ◽  
Groundwater Flow ◽  
Solute Transport ◽  
Transport Process ◽  
Homogeneous Model ◽  
Estimation Methods ◽  
Aquifer Heterogeneity ◽  
Heterogeneous Aquifer ◽  
Tracer Distribution ◽  
Parameter Estimation Methods

<p>Protection and management of groundwater resources demand high-resolution distributions of hydraulic parameters (e.g., hydraulic conductivity (K) and specific storage (Ss)) of aquifers. In the past, these parameters were obtained by traditional analytical solutions (e.g., Theis (1935) or Cooper and Jacob (1946)). However, traditional methods assume the aquifer to be homogeneous and yield the equivalent parameter, which are averages over a large volume and are insufficient for predicting groundwater flow and solute transport process (Butler & Liu, 1993). For obtaining the aquifer heterogeneity, some scholars have used kriging (e.g., Illman et al., 2010) and hydraulic tomography (HT) (e.g., Yeh & Liu, 2000; Zhu & Yeh, 2005) to describe the K distribution.</p><p>In this study, the laboratory heterogeneous aquifer sandbox is used to investigate the effect of different hydraulic parameter estimation methods on predicting groundwater flow and solute transport process. Conventional equivalent homogeneous model, kriging and HT are used to characterize the heterogeneity of sandbox aquifer. A number of the steady-state head data are collected from a series of single-hole pumping tests in the lab sandbox, and are then used to estimate the K fields of the sandbox aquifer by the steady-state inverse modeling in HT survey which was conducted using the SimSLE algorithm (Simultaneous SLE, Xiang et al., 2009), a built-in function of the software package of VSAFT2. The 40 K core samples from the sandbox aquifer are collected by the Darcy experiments, and are then used to obtain K fields through kriging which was conducted using the software package of Surfer 13. The role of prior information on improving HT survey is then discussed. The K estimates by different methods are used to predict the process of steady-state groundwater flow and solute transport, and evaluate the merits and demerits of different methods, investigate the effect of aquifer heterogeneity on groundwater flow and solute transport.</p><p>According to lab sandbox experiments results, we concluded that compared with kriging, HT can get higher precision to characterize the aquifer heterogeneity and predict the process of groundwater flow and solute transport. The 40 K fields from the K core samples are used as priori information of HT survey can promote the accuracy of K estimates. The conventional equivalent homogeneous model cannot accurately predict the process of groundwater flow and solute transport in heterogeneous aquifer. The enhancement of aquifer heterogeneity will lead to the enhancement of the spatial variability of tracer distribution and migration path, and the dominant channel directly determines the migration path and tracer distribution.</p>

scholarly journals Technical note: Analytical drawdown solution for steady-state pumping tests in two-dimensional isotropic heterogeneous aquifers

2016 ◽  
Vol 20 (5) ◽  
pp. 1655-1667 ◽  
Author(s):  
Alraune Zech ◽  
Sabine Attinger
Keyword(s):  
Steady State ◽  
Correlation Length ◽  
Heterogeneous Media ◽  
Radial Distance ◽  
Pumping Test ◽  
Two Dimensional ◽  
Aquifer Heterogeneity ◽  
Pumping Tests ◽  
Flow Solution ◽  
Ensemble Mean

Abstract. A new method is presented which allows interpreting steady-state pumping tests in heterogeneous isotropic transmissivity fields. In contrast to mean uniform flow, pumping test drawdowns in heterogeneous media cannot be described by a single effective or equivalent value of hydraulic transmissivity. An effective description of transmissivity is required, being a function of the radial distance to the well and including the parameters of log-transmissivity: mean, variance, and correlation length. Such a model is provided by the upscaling procedure radial coarse graining, which describes the transition of near-well to far-field transmissivity effectively. Based on this approach, an analytical solution for a steady-state pumping test drawdown is deduced. The so-called effective well flow solution is derived for two cases: the ensemble mean of pumping tests and the drawdown within an individual heterogeneous transmissivity field. The analytical form of the solution allows inversely estimating the parameters of aquifer heterogeneity. For comparison with the effective well flow solution, virtual pumping tests are performed and analysed for both cases, the ensemble mean drawdown and pumping tests at individual transmissivity fields. Interpretation of ensemble mean drawdowns showed proof of the upscaling method. The effective well flow solution reproduces the drawdown for two-dimensional pumping tests in heterogeneous media in contrast to Thiem's solution for homogeneous media. Multiple pumping tests conducted at different locations within an individual transmissivity field are analysed, making use of the effective well flow solution to show that all statistical parameters of aquifer heterogeneity can be inferred under field conditions. Thus, the presented method is a promising tool with which to estimate parameters of aquifer heterogeneity, in particular variance and horizontal correlation length of log-transmissivity fields from steady-state pumping test measurements.

Dolomitization-induced aquifer heterogeneity: Evidence from the upper Floridan aquifer, southwest Florida

2002 ◽  
Vol 114 (4) ◽  
pp. 419-427 ◽  
Author(s):  
Robert G. Maliva ◽  
Gordon P. Kennedy ◽  
W. Kirk Martin ◽  
Thomas M. Missimer ◽  
Elizabeth S. Owosina ◽  
...  
Keyword(s):  
Aquifer Heterogeneity ◽  
Southwest Florida ◽  
Floridan Aquifer ◽  
Upper Floridan Aquifer

An Investigation of the Ability of Induced Polarization to Resolve Aquifer Heterogeneity in an Unconsolidated Sedimentary Aquifer

2011 ◽  
Author(s):  
Lee Slater ◽  
Andrew Binley ◽  
Warren Barrash ◽  
John Keery ◽  
Jeanette Montrey ◽  
...  
Keyword(s):  
Induced Polarization ◽  
Aquifer Heterogeneity ◽  
Sedimentary Aquifer
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