Ground Water[JOURNAL]
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200 papers
Transience of Coastal Water Table Rise in Response to Sea-Level Rise.
Bosserelle AL, Morgan LK
Ground Water · 2025 · PMID 40318015 · Full text
Coastal shallow groundwater is susceptible to adverse sea-level rise (SLR) impacts. Existing research primarily focuses on SLR-induced salinization of coastal aquifers. There is limited understanding of the magnitudes an...
Coastal shallow groundwater is susceptible to adverse sea-level rise (SLR) impacts. Existing research primarily focuses on SLR-induced salinization of coastal aquifers. There is limited understanding of the magnitudes and rates of water table rise in response to SLR, which could lead to groundwater flooding and associated infrastructure challenges. This study used a variable-density groundwater flow model to quantify the transient movement of the water table in response to various SLR scenarios and rates, considering a range of aquifer parameters for both fixed-head and fixed-flux inland boundary conditions. The SLR scenario based on realistic and progressive SLR projections resulted in a smaller water table rise than the instantaneous or gradual SLR scenarios at 100 years, despite a final identical SLR. Rates of water table rise were always less than SLR, decreased with distance from the coastline, and were proportional to SLR. The magnitude and rate of water table rise in response to SLR were largest for fixed-flux conditions. It also took longer for the rate of water table rise to equilibrate after the commencement of SLR for fixed-flux conditions than for fixed-head conditions. As such, fixed-flux conditions represent a greater hazard for water table rise, and the maximum impact may not be experienced for decades. This delayed response poses challenges to planners and managers of coastal groundwater systems. Introducing a drain reduced water table rise more on the inland side of the drain than on the coastal side. Subsurface infrastructure may limit SLR impacts, but further effects need to be carefully considered.
Validation of the Impacts of Recent Aquifer Management on the Eastern Snake Plain Aquifer in Idaho, USA.
Hoekema DJ, Ryu J, Abatzoglou JT
Ground Water · 2025 · PMID 40265727 · Publisher ↗
An ongoing major challenge faced in portions of the western United States is to stop the decline of aquifers that are hydraulically connected to rivers. As these aquifers decline, streamflow is depleted, resulting in imp...
An ongoing major challenge faced in portions of the western United States is to stop the decline of aquifers that are hydraulically connected to rivers. As these aquifers decline, streamflow is depleted, resulting in impacts to agriculture, environmental flows, and hydropower production. In 2014, the Idaho Water Resource Board initiated an aquifer recharge program, and in 2015 a historic settlement agreement (hereafter referred to as the Settlement Agreement) was signed by surface water users with senior water rights and groundwater pumpers with junior water rights to stop the decline of the eastern Snake Plain Aquifer (ESPA) in southern Idaho (SWC-IGWA 2015). Here, we assess mitigation measures they have undertaken to reverse the downward trajectory of groundwater levels in the ESPA using drought indices correlated to the combined head change of a suite of groundwater monitoring wells. The results were then compared against the predictions of the Enhanced Snake Plain Aquifer Model (ESPAM), which is a MODFLOW-based aquifer model. The drought indices indicate that without the aquifer recharge program and reductions in groundwater pumping, the aquifer head would have been 1.1 to 1.3 m lower than observed in 2023, indicating implemented water management practices reduced the volumetric loss to the aquifer by 2500 million cubic meters (2,000,000 acre-feet). The result, therefore, implies that Idaho water users and managers have succeeded in changing the trajectory of ESPA water levels.
Comparing Physics-Based, Conceptual and Machine-Learning Models to Predict Groundwater Levels by BMA.
Wöhling T, Delgadillo AOC, Kraft M … +1 more , Guthke A
Ground Water · 2025 · PMID 40256895 · Full text
Groundwater level observations are used as decision variables for aquifer management, often in conjunction with models to provide predictions for operational forecasting. In this study, we compare different model classes...
Groundwater level observations are used as decision variables for aquifer management, often in conjunction with models to provide predictions for operational forecasting. In this study, we compare different model classes for this task: a spatially explicit 3D groundwater flow model (MODFLOW), an eigenmodel, a transfer-function model, and three machine learning models, namely, multi-layer perceptron models, long short-term memory models, and random forest models. The models differ widely in their complexity, input requirements, calibration effort, and run-times. They are tested on four groundwater level time series from the Wairau Aquifer in New Zealand to investigate the potential of the data-driven approaches to outperform the MODFLOW model in predicting individual target wells. Further, we wish to reveal whether the MODFLOW model has advantages in predicting all four wells simultaneously because it can use the available information in a physics-based, integrated manner, or whether structural limitations spoil this effect. Our results demonstrate that data-driven models with low input requirements and short run-times are competitive candidates for local groundwater level predictions even for system states that lie outside the calibration data range. There is no "single best" model that performs best in all cases, which motivates ensemble forecasting with different model classes using Bayesian model averaging. The obtained Bayesian model weights clearly favor MODFLOW when targeting all wells simultaneously, even though the competing approaches had the chance to fine-tune for each tested well individually. This is a remarkable result that strengthens the argument for physics-based approaches even for seemingly "simple" groundwater level prediction tasks.
Quantification and Analysis of Hydrograph Behavior Using Groundwater Signatures.
Collenteur RA, Vonk MA, Haaf E
Ground Water · 2025 · PMID 40243592 · Full text
The study of hydraulic head changes over time is a common task for groundwater hydrologists. Groundwater signatures are numerical metrics, or statistical aggregates, that quantify the behavior observed in hydraulic head...
The study of hydraulic head changes over time is a common task for groundwater hydrologists. Groundwater signatures are numerical metrics, or statistical aggregates, that quantify the behavior observed in hydraulic head hydrographs. Signatures can be helpful in a number of classical hydrological tasks, such as hydrograph classification, clustering, change detection, and model evaluation, selection, and calibration. Despite the potential benefits of using signatures in groundwater studies, their application has not yet been thoroughly explored. To support research into the application of signatures in groundwater studies, we introduce the new groundwater signatures module from the Pastas software. The signatures module is written in Python, fully tested and documented, and available as open-source software under the MIT license. In this paper, it is shown how the signatures are tested and can be used in practical applications through two examples. In the first example, signatures are used to characterize and cluster monitoring wells in a nationwide monitoring network in Switzerland. In the second example, signatures are used to evaluate how well different groundwater model structures simulate the heads. Future research opportunities involving groundwater signatures are discussed.
A New Explicit Solver for MODFLOW Enabling Small Time Step Simulations.
Azari B, Waldron B, Jazaei F
Ground Water · 2025 · PMID 40202017 · Publisher ↗
Surface water (SW) and groundwater (GW) models, such as MODFLOW and HEC-RAS, have been explored to simulate the complexities of SW-GW interactions. However, individual models are not capable of capturing the full complex...
Surface water (SW) and groundwater (GW) models, such as MODFLOW and HEC-RAS, have been explored to simulate the complexities of SW-GW interactions. However, individual models are not capable of capturing the full complexity of these interactions. To overcome individual models' shortcomings, researchers introduced the model coupling concept. This concept helps compensate for each individual model's shortcomings and incorporates the models' advantages. However, challenges arise from temporal scale disparities between SW and GW models. To tackle the temporal scale issue, this study introduces the novel explicit solver (EXP1) for MODFLOW 2005, enabling GW modeling using small time steps matching SW models (i.e., 15 min) by reducing runtime and computational burden. The EXP1 solver incorporates an integrated stability criterion to ensure the stability of explicit schemes, and it was systematically evaluated against the Preconditioned Conjugate Gradient (PCG) solver across various scenarios, including a 1-dimensional, 2-dimensional, and a vast 3-dimensional model. Results demonstrated the efficiency and accuracy of EXP1 in predicting groundwater heads and water budget, along with considerably reduced runtimes of up to 33% compared with the PCG solver, with less than 0.4% discrepancy in the water budget. These findings underscore the effectiveness of EXP1 in facilitating groundwater small time step simulations and bridging the temporal scale gap between SW and GW models.
Matrix Diffusion Controls Mountain Hillslope Groundwater Ages and Inferred Storage Dynamics.
Thiros NE, Woodburn ER, Gardner WP … +2 more , Dennedy-Frank JP, Williams KH
Ground Water · 2025 · PMID 40156323 · Full text
Groundwater age distributions provide fundamental insights on coupled water and biogeochemical processes in mountain watersheds. Field-based studies have found mixtures of young and old-aged groundwater in mountain catch...
Groundwater age distributions provide fundamental insights on coupled water and biogeochemical processes in mountain watersheds. Field-based studies have found mixtures of young and old-aged groundwater in mountain catchments underlain by bedrock; yet, the processes that dictate these groundwater age distributions are poorly understood. In this work, we use the coupled ParFlow-CLM integrated hydrologic and EcoSLIM particle tracking models to simulate groundwater age distributions on a lower montane hillslope in the East River Watershed, Colorado (USA). We develop a convolution-based approach to propagate fracture-matrix diffusion processes to the EcoSLIM advection-dominated age distributions. We compare observed H and He concentrations from two groundwater wells against model predictions that have varying advective transport times and matrix diffusion magnitudes. Based on a Monte Carlo analysis that considers uncertain matrix and fracture parameters, we find that matrix diffusion is needed to jointly predict H and He observations at both wells. The advection-dominated age distributions lack adequate mixing of young and old-aged water to capture the observed co-occurrence of H and He. The model scenario that best matches the H, He, and water level observations when considering both advective flowpath and matrix diffusion mixing processes has a dynamic bedrock groundwater reservoir that is susceptible to considerable storage losses during low-snow periods. This dynamic groundwater system amplifies the need to assimilate deeper bedrock groundwater into watershed hydro-biogeochemical predictions. This work further highlights the importance of considering matrix diffusion when interpreting environmental tracers in bedrock groundwater systems.
Neonicotinoids in Groundwater: Persistent Contaminants and Unresolved Risks.
Romano C
Ground Water · 2025 · PMID 40156314 · Publisher ↗
Abstract loading — click title to view on PubMed.
Model-Based Approach to Determine Critical Design Parameters for Tandem Circulation Well Remediation Systems.
Yang S, Wen Z, Zhu Q … +2 more , Yuan S, Li Y
Ground Water · 2025 · PMID 40145771 · Publisher ↗
Aerobic bioremediation enhanced by tandem circulation well (TCW)-generated aeration in a groundwater circulation systems has emerged as a novel, environmentally friendly, and cost-effective remediation approach with grow...
Aerobic bioremediation enhanced by tandem circulation well (TCW)-generated aeration in a groundwater circulation systems has emerged as a novel, environmentally friendly, and cost-effective remediation approach with growing recognition. For TCW, previous investigations have been limited to few laboratory experiments, simulation precision, acquisition of reaction kinetic parameters, and effective guidance for technology optimization. In this work, we employed regionalized sensitivity analysis with Latin Hypercube Sampling (LHS) to identify the most sensitive parameters in laboratory TCW experiments, reducing the number of parameters to estimate. The estimated parameters were utilized to construct a reactive transport model with periodic boundary conditions, enhancing its universality for in-situ trichloroethylene (TCE) bioremediation through electrolysis considering mutual interactions among well clusters. The results revealed the influence mechanisms of the operating parameters and well spacing on remediation performance. Besides, it was found that degradation efficiency was limited by DO oversaturation in the wellbore. However, it could be promoted by optimization of operation parameters, using an optimization index, the ratio of current to pumping rate ( ). Finally, simulation results implied two suggestions for well spacing: (1) Designing a remediation site with a higher aspect ratio will enhance the performance of this technology. (2) With a larger area, both current intensity and pumping rate need to be proportionally increased in alignment with the enlarged area to ensure optimal efficiency. This work improves the precision of characterizing the TCW system, guiding the determination of reaction kinetics parameters and optimization of critical design parameters, including operational parameters and well spacing, in remediation sites, thereby achieving superior remediation performance in field applications.
Consideration of Grid Cell Size to Represent Stream Networks for the Conterminous United States.
Fleming BJ, Belitz K, Killian CD
Ground Water · 2025 · PMID 40125654 · Full text
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Breakthrough Curve Separation Using Applied Solute Tracers.
Paradis CJ, Sultana R, Dangelmayr MA … +2 more , Johnson RH, Kent RD
Ground Water · 2025 · PMID 40099386 · Publisher ↗
The separation of advection and dispersion from the breakthrough curve of a potentially reactive solute can help determine if reactive transport mechanisms occurred. This is typically done by solving the advection-disper...
The separation of advection and dispersion from the breakthrough curve of a potentially reactive solute can help determine if reactive transport mechanisms occurred. This is typically done by solving the advection-dispersion equation and fitting the breakthrough curve of an applied non-reactive solute tracer by adjusting groundwater velocity and the dispersion coefficient; the values of velocity and dispersion are then applied to the breakthrough curve of the potentially reactive solute, and any residuals can be fitted with the appropriate reactive transport mechanisms. A simpler approach is to plot the dimensionless relative concentrations of the non-reactive and reactive solutes on the same breakthrough curves; thus, any differences between the two curves can be attributed to reactive transport. The method proposed here can allow for separating advection and dispersion from the breakthrough curve of a potentially reactive solute based on data only, as opposed to model-derived fitting of groundwater velocity and dispersion, all while preserving the true concentration, as opposed to the dimensionless relative concentration, of the potentially reactive solute. A new measure of overall solute reactivity is also introduced that summates relative temporal moments to quantify and rank the reactivity of a suite of solutes. The method is described and applied to numerical model simulations and field tracer data to demonstrate its utility for combined visual-quantitative breakthrough curve separation to better characterize reactive solute transport in applied tracer studies.
Using Advective Transport Phenomena to Account for Uncertainty of Conductivity in Monitoring Design.
de Lange WJ
Ground Water · 2025 · PMID 40086884 · Full text
Engineering practice in monitoring design aims at the optimum number of observation wells needed to assess the growth of a contaminated volume groundwater, the plume. Available methodologies rely on a combination of a nu...
Engineering practice in monitoring design aims at the optimum number of observation wells needed to assess the growth of a contaminated volume groundwater, the plume. Available methodologies rely on a combination of a numerical groundwater transport model, GIS-techniques and an optimization technique and require a relative huge amount of data and computer resources. The method of advective transport phenomena enables to calculate the longitudinal and vertical growth of a contaminant plume along the flow path by simple analytic expressions using only three stochastic parameters, the log conductivity variance and the horizontal and vertical characteristic lengths, that together describe the heterogeneity of the aquifer. In previous work, the calculated plume growth has been verified in 12 large experiments all over the world. The method is used to investigate the relationship between uncertainty in the conductivity variation and the plume growth by calculation of the spreading of water particles in a vertical section along the traveled path. In a very heterogeneous aquifer, virtually all water particles spread forward about equally generating a limited forward growth compared to the traveled distance that is not sensitive to uncertainty in the conductivity. In a nearly homogenous aquifer, only a part of the water particles is spread forward, which is repeated at different depths along the traveled path causing significant uncertainty in the position and length of the plume growth. Therefore, an observation network should be designed more densely in a homogeneous aquifer than in a heterogeneous one. A calculation tool is provided.
Information-Driven Sequential Inversion for Transient Hydraulic Tomography.
Muraharirao PC, Kambhammettu BVNP, Pinninti R … +1 more , Sangamreddi C
Ground Water · 2025 · PMID 40071864 · Publisher ↗
Transient hydraulic tomography (THT) is proven to be effective in representing hydraulic and storage properties in diverse hydrogeologic settings. Sequential inversion of THT is computationally efficient, however, its ac...
Transient hydraulic tomography (THT) is proven to be effective in representing hydraulic and storage properties in diverse hydrogeologic settings. Sequential inversion of THT is computationally efficient, however, its accuracy is constrained by the number and sequence of pumping datasets used in the inversion. While signal-to-noise ratio (SNR) is commonly used to regulate the order of pumping datasets, it often disregards the information content. We propose an alternate strategy to rank the pumping ports based on the information contained in the data for use with inversion. A non-parametric Gringorten plotting position was used to generate cumulative distribution functions (CDFs) of the transient datasets, with the CDF corresponding to the maximum drawdown port set as a reference. The Kullback-Leibler divergence (KLD) is employed to quantify variations in time-drawdown datasets by statistically measuring the divergence from the reference distribution. Pumping ports are then ranked in the decreasing order of KLD and further used in the inversion. The proposed methodology is tested under a controlled environment using a laboratory sandbox model. Discrete wavelet transform (DWT) was applied to denoise the raw pumping datasets, and PEST coupled with MODFLOW was used to perform the inversion. The performance of KLD-assisted inversion (RMSE = 0.278 ± 0.177 cm) is found to be superior to SNR-assisted inversion (RMSE = 1.075 ± 0.990 cm). Further, a reduction in THT data (by 68%) by specifying a threshold on KLD (>10) has drastically reduced the computational time (by 64%) with commensurable accuracy (RMSE = 0.265 ± 0.121 cm). Our findings lead to the conclusion that sequential inversion of THT with information-driven datasets outperforms quality-driven datasets, even with reduced pump-test data.
Hydrogeologic Heterogeneity Impacts on Fresh-Saltwater Interaction in Jeju Volcanic Island, Korea.
Koh CS, Koh EH, Park WB … +1 more , Kim MC
Ground Water · 2025 · PMID 40062796 · Publisher ↗
Jeju volcanic island of South Korea is characterized by hydrogeological heterogeneity, which has resulted in complex environments in a coastal aquifer system. The shape of the fresh-saltwater transition zone (FSTZ) and d...
Jeju volcanic island of South Korea is characterized by hydrogeological heterogeneity, which has resulted in complex environments in a coastal aquifer system. The shape of the fresh-saltwater transition zone (FSTZ) and depth-dependent tidal influences on fresh-saltwater interaction in the eastern part of Jeju Island were examined by assessing geological logs from drilling cores, vertical profiles of specific conductance (SC) and temperature from geophysical logging, and performing time series analysis of groundwater level and multi-depth SC (collected from multiple sensors installed at various borehole depths). A sharp interface and step-like FSTZ were developed in the hyaloclastite and lava layers, respectively. The tidal influences on groundwater levels were highly associated with the distance from the coastline; however, SC data revealed different responses to tidal changes according to depth. Based on these data, we propose a conceptual hydrogeological model that incorporates different volcanic structures, including hyaloclastite and lava layers. Conduit flow through the highly permeable hyaloclastite layers led to the development of a sharp interface of FSTZ and disturbed the tidal signals on SC by acting as a preferential pathway for fast and abundant fresh groundwater discharge. Conversely, in the lava layers characterized by the successive formation of high- and low-permeability layers, boundary flows in the geological boundaries created a step-like FSTZ and showed a relatively high association between the tide and SC. This study highlights the crucial role of hydrogeological heterogeneity in determining the complex behaviors of fresh-saltwater interactions in the coastal aquifers of volcanic regions.
Generating a Statistically Constrained Quaternary Model of a Buried Bedrock Valley Using FDEM.
Gorrie C, Steelman CM, Conway-White O … +3 more , Smiarowski A, Arnaud E, Parker BL
Ground Water · 2025 · PMID 40052478 · Full text
An airborne electromagnetic (AEM) survey was conducted using the Resolve™ frequency-domain system over a buried bedrock valley near Elora, Ontario, Canada. A statistical bootstrapping approach was used to establish a rel...
An airborne electromagnetic (AEM) survey was conducted using the Resolve™ frequency-domain system over a buried bedrock valley near Elora, Ontario, Canada. A statistical bootstrapping approach was used to establish a relationship between the electrical resistivity from spatially interpolated one-dimensional AEM resistivity models and the lithostratigraphy of Quaternary sediments logged in continuously cored holes located within and adjacent to the buried bedrock valley. Three lithology types were classified using a bootstrapping approach: (i) clay, (ii) sandy to muddy diamicton with the presence of clasts, and (iii) sand/gravel. The statistically derived ranges in electrical resistivity from the model were used to generate a lithostratigraphic model of the Quaternary deposits along the valley axis. The resulting lithology model differentiated more electrically resistive coarse-grained sand and gravel from electrically conductive finer-grained clay-rich tills; but was not able to resolve interbedded layers associated with complex fluvial deposits. Modeled Quaternary deposit architecture and bedrock morphology along two transects orthogonal to the valley axis were consistent with co-located surface electrical resistivity tomography models and borehole natural gamma logs, indicating that the AEM method, when calibrated using high-quality continuous-core logs, can support quantitative conceptualizations of complex Quaternary architecture within and around a buried bedrock valley. Key limitations in this approach were the reduced vertical resolution of the AEM method and the inability to resolve thinly bedded layers (meter scale) identified in the core logs that may have a hydrogeologic influence. This study demonstrates the utility of combining airborne electrical methods with high-resolution geological logs through statistical analysis to constrain hydrostratigraphic architecture at scales relevant to municipal groundwater flow systems.
ARCHI: A New R Package for Automated Imputation of Regionally Correlated Hydrologic Records.
Levy ZF, Glas RL, Stagnitta TJ … +1 more , Terry N
Ground Water · 2025 · PMID 40019092 · Full text
Missing data in hydrological records can limit resource assessment, process understanding, and predictive modeling. Here, we present ARCHI (Automated Regional Correlation Analysis for Hydrologic Record Imputation), a new...
Missing data in hydrological records can limit resource assessment, process understanding, and predictive modeling. Here, we present ARCHI (Automated Regional Correlation Analysis for Hydrologic Record Imputation), a new, open-source software package in R designed to aggregate, impute, cluster, and visualize regionally correlated hydrologic records. ARCHI imputes missing data in "target" records by linear regression using more complete "reference" records as predictors. Automated imputation is implemented using a novel, iterative algorithm that allows each site to be considered a target or reference for regression, growing the pool of complete references with each imputed record until viable gap-filling ceases. Users can limit artifacts from spurious correlations by specifying model-acceptance criteria and applying geospatial, correlation, and group-based filters to control reference selection. ARCHI provides additional functions for visualizing results, clustering records with similar correlation structures, evaluating holdout data, and interactive parameterization with an accessible and intuitive graphical user interface (GUI). This methods brief provides an overview of the ARCHI package, modeling guidelines, and benchmarking on two regional groundwater-level datasets from the Central Valley, CA and Long Island, NY. We evaluate ARCHI alongside widely used multivariate imputation software to highlight and contextualize its computational efficiency, imputation accuracy, and model transparency when applied to large, groundwater-level datasets.
From stoning to building: How to energize science meetings.
Bickford BJ
Ground Water · 2025 · PMID 39976377 · Publisher ↗
Abstract loading — click title to view on PubMed.
A New Groundwater Energy Transport Model for the MODFLOW Hydrologic Simulator.
Morway ED, Provost AM, Langevin CD … +4 more , Hughes JD, Russcher MJ, Chen CY, Lin YF
Ground Water · 2025 · PMID 39952895 · Full text
Heat transport in the subsurface is an important aspect of research related to the effects of a warming climate on ecological services (i.e., cold-water refugia); the development of geothermal resources for energy bankin...
Heat transport in the subsurface is an important aspect of research related to the effects of a warming climate on ecological services (i.e., cold-water refugia); the development of geothermal resources for energy banking schemes (i.e., aquifer thermal energy storage [ATES]); and the effects of temperature on other aspects of groundwater quality, such as nutrient cycling. Historically, simulation of heat transport using the MODFLOW groundwater simulator and related codes was performed by scaling the input parameters of a solute-transport model to emulate heat transport. However, that approach required additional pre- and post-processing of input and output and could not account for the variation in effective thermal storage and transport properties during transient, unsaturated flow, for example. True heat-transport capabilities in the context of MODFLOW were first introduced in a variant called USG-Transport. More recently, a new groundwater energy-transport (GWE) model type has been added to MODFLOW 6, the core version of the MODFLOW hydrologic simulator. GWE supports the simulation of heat transport on structured or unstructured grids as well as within and between features of advanced packages that represent streams, lakes, multi-aquifer wells, and the unsaturated zone. GWE is integrated within MODFLOW 6 and is accessible through the FloPy Python package and the MODFLOW 6 application programming interface (API). An example simulation demonstrates conduction between grid cells through both the water and the solid aquifer material, including thermal bleeding from saturated overburden cells into a groundwater flow field.
Sustainable Irrigation: A Shift From Conventional to Solar Tube-Wells.
Khan A, Ahmed I, Khair SM
Ground Water · 2025 · PMID 39932101 · Publisher ↗
This study examines the factors influencing the adoption of solar tube well technology for groundwater extraction in the agriculture sector, focusing on the Balochistan region of Pakistan. Water scarcity is a major chall...
This study examines the factors influencing the adoption of solar tube well technology for groundwater extraction in the agriculture sector, focusing on the Balochistan region of Pakistan. Water scarcity is a major challenge in this region due to declining groundwater level and unreliable power supplies. The study uses a binary logit regression model to analyze the factors that determine the adoption of solar tube wells by farmers. The study took into account variables such as age, education level of household head and access to credit, farmers' perception of groundwater depletion, number of hours of tube well operation, and cost of adopting solar technology. The results indicate that education level and experience positively influence farmers' ability to use solar tube wells. Education provides farmers with the knowledge to understand modern farming methods and the benefits of solar technology. In addition, the cost-effectiveness and increased operating hours of solar tube wells contribute significantly to their adoption. Farmers' concerns about greater groundwater depletion also influenced their decisions, with those seeing groundwater decline more likely to adopt solar technology. The results also suggest that policies that promote access to credit and reduce the initial cost of solar tube well adoption can further encourage farmer's adoption decision.
R.W. Gillham and the Role of Capillary Fringe Processes in Shallow Aquifer Behavior.
Vogan J, Shikaze S, Doerken K
Ground Water · 2025 · PMID 39907415 · Publisher ↗
Abstract loading — click title to view on PubMed.
Impact of Long Well Screens on Monitoring of the Freshwater-Saltwater Transition Zone.
Croteau F, Coulon C, Molson J … +1 more , Lemieux JM
Ground Water · 2025 · PMID 39854080 · Full text
Deep monitoring wells with long screens crossing the transition zone between freshwater and saltwater are often used in coastal areas to characterize fresh groundwater resources and the depth of saline groundwater. Howev...
Deep monitoring wells with long screens crossing the transition zone between freshwater and saltwater are often used in coastal areas to characterize fresh groundwater resources and the depth of saline groundwater. However, past studies have demonstrated that long-screen wells can lead to biased observations of the transition zone, since vertical flow within the borehole can modify the shape and elevation of the transition zone in and around the borehole compared to undisturbed conditions without a well. Here, field observations and variable-density numerical flow simulations are used to evaluate, under natural flow conditions, how the installation of long-screen wells can provide time-varying biased observations of the freshwater-saltwater transition zone, and how various aquifer and well parameters affect the magnitude of these biases. Results show that long-screen wells can lead to a more dispersed interface, an upward displacement of the transition zone of between 5 and 10 m, and a salinity decrease in the saltwater portion of the well on the order of 10 to 15 g/L. The perturbations take up to 5 years to fully develop and stabilize. The degree of displacement depends on the screen diameter, screen length, aquifer anisotropy, and hydraulic conductivity, whereas the displacement is independent of the distance of the well from the coast. This analysis provides insight into which well and aquifer characteristics increase the risk of obtaining biased observations in long-screen wells, and provides orders of magnitude for these biases.
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