Groundwater最新文献

{"title":"Incorporating Electrostatic Coupling Effects into Multispecies Solute Transport Simulations with MODFLOW","authors":"Rodrigo Pérez-Illanes,&nbsp;Christian D. Langevin,&nbsp;Muhammad Muniruzzaman,&nbsp;Massimo Rolle","doi":"10.1111/gwat.70033","DOIUrl":"10.1111/gwat.70033","url":null,"abstract":"<p>Solute transport simulators aiming to accurately describe the transport of charged chemical species in porous media need to account for electrostatic coupling effects. Each ion in pore water possesses a specific electric charge and molecular diffusion coefficient, properties that determine their mobility and the overall charge balance of aqueous solutions. Depending on the charge, concentration and aqueous diffusion coefficient, the displacement of an ion in solution influences, and is in turn influenced by, other ions in solution by means of electrostatic interactions. This phenomenon has been studied with experiments and numerical simulations in diffusion-dominated regimes, as well as in advection-dominated flow-through systems, showing that electrostatic coupling effects play a relevant role in the spatiotemporal prediction of ion concentrations. However, there is limited availability of solute transport codes incorporating electrostatic coupling, limiting applications of multispecies ionic transport at different scales. This article elaborates on the topic of electrostatic coupling and presents a methodology for incorporating the effect into multispecies solute transport simulations with MODFLOW. The integration is achieved through the Application Programming Interface of the program (MODFLOW-API). This interface enables the access to concentrations and dispersion coefficients of all species during the simulation, which are necessary to calculate a dispersive correction that effectively incorporates electrostatic coupling into the model. Numerical results demonstrate the effectiveness of the coupling strategy, benchmarking the implementation with previously validated numerical simulators and with experimental data.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"210-222"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145644035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Groundwater Salinity: Applying the Specific Conductance and Water Type Proxy","authors":"R. Blaine McCleskey,&nbsp;Charles A. Cravotta III,&nbsp;Katherine J. Knierim,&nbsp;Paul E. Stackelberg,&nbsp;Courtney Killian","doi":"10.1111/gwat.70038","DOIUrl":"10.1111/gwat.70038","url":null,"abstract":"<p>Groundwater is increasingly needed for water supplies but may have limited utility in some locations because of its salinity. Salinity, often expressed as total dissolved solid (TDS), is frequently estimated using specific conductance (SC) measurements. However, the commonly used proxy (0.65 multiplied by SC to indicate TDS, common in many handheld meters) can result in inaccurate TDS estimates. First, the TDS–SC relationship is not linear over the entire concentration range of groundwater. Furthermore, the TDS (and salinity)–SC relationships vary substantially depending on the major-ion composition. Here we develop a proxy method utilizing SC and major-ion water type to estimate TDS and salinity specifically for groundwaters. Compared to most surface waters, groundwater tends to have a wider range of salinity (fresh to highly saline) and higher concentrations of bedrock-derived solutes such as carbonate ions, silica, and many other ions. The dataset used to develop the proxies includes water chemistry data from 149,059 discrete groundwater samples. The groundwater proxies, which employ nonlinear log–log relations, utilize five water types (HCO₃, Cl, Ca-Mg-SO₄, Na-K-SO₄, and mixed waters), are accurate (median percent difference between TDS and salinity determined using the proxy compared to discrete measurements was &lt;±0.8%) over a wide range of SC (up to 200 mS/cm), rapid, cost-effective, and can be measured on-site.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"150-160"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145678747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing Groundwater Sampling Devices for Denitrification Assessment Using the N2/Ar Method","authors":"Felix Fahrenbach,&nbsp;Thomas R. Rüde","doi":"10.1111/gwat.70047","DOIUrl":"10.1111/gwat.70047","url":null,"abstract":"<p>The N₂/Ar method is valuable for studying legacy nitrate and denitrification progress in groundwater systems. It uses dissolved N₂ and Ar concentrations to calculate the amount of N₂ originating from denitrification (excess-N₂). Successfully applying the method requires accurate values of N₂ and Ar concentrations. Therefore, avoiding degassing and atmospheric contamination during groundwater sampling is crucial for reliable results. In this study, we focus on the effect of sampling devices on N₂, Ar, and the resulting excess-N₂ concentrations. To evaluate this effect over a wide concentration range, we sampled 14 observation wells. One sample was collected using a submersible pump and another using a bladder pump. Furthermore, we collected multiple samples with both pumps at a fifteenth site to assess reproducibility. Additionally, we used a point-source bailer for sampling at this site. The major ion concentrations show that the sampling device does not significantly influence the sample chemistry. In contrast, the measured N₂, Ar, and calculated excess-N₂ concentrations significantly differ between the sampling devices. Overall, the samples collected with the submersible pump show the highest N₂ and Ar concentrations, resulting in the highest excess-N₂ concentrations. N₂ and Ar concentrations of the bladder pump samples are lower, resulting in lower excess-N₂ concentrations. The bailer samples show lower N₂ but similar Ar concentrations to the submersible pump samples, leading to the lowest excess-N₂ concentrations. We conclude that a submersible pump is practical and suitable for collecting groundwater samples to assess denitrification by the N₂/Ar method.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"235-242"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990959/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146088447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Read the Whole Issue!","authors":"Kenneth R. Bradbury","doi":"10.1111/gwat.70055","DOIUrl":"10.1111/gwat.70055","url":null,"abstract":"&lt;p&gt;After 61 years as a printed publication, &lt;i&gt;Groundwater&lt;/i&gt; became fully digital in 2024, with no published hard copies, and the same has happened with most other scientific journals. Digital publishing has many advantages, including lower cost, rapid dissemination, easy storage, and digital searching. But something is lost when readers now download and view one article at a time (as several colleagues have told me they do) rather than discovering an entire issue. At &lt;i&gt;Groundwater&lt;/i&gt; we still compile and publish six issues a year, and while research papers remain the core of each one, the issues also contain editorials, book reviews, case studies, methods briefs, media spotlights, technology features, and history articles that will broaden anyone's hydrogeologic knowledge. When I was a graduate student at the University of Wisconsin-Madison over 40 years ago, scientific journals were only available in physical paper copies. Research for my dissertation or for class assignments entailed visiting the library and pulling out full copies of journals for the relevant articles, and the references in these often directed me to other hard copies of &lt;i&gt;Groundwater&lt;/i&gt; (or &lt;i&gt;Ground Water&lt;/i&gt;, as it was spelled then). Browsing these issues, I discovered a treasure trove of interesting information on hydrogeologic topics that I previously hadn't thought or learned much about. Here were provocative editorials, discussions, field methods, the latest research, case studies, hydrogeologic histories, and more. This browsing gave me a broad vision of the scope of groundwater science and exposure to new and evolving ideas that weren't currently being covered in my classes or textbooks. It also made me familiar with the names and institutions of scientists and practitioners doing the latest work both in and outside my immediate field of interest. What's more, I saw numerous examples of good presentation styles, organization, and figure and table layouts. Looking back, this casual browsing helped make me a more rounded hydrogeologist as well as a better writer.&lt;/p&gt;&lt;p&gt;Sadly, browsing journals this way is now far less common, though, at least in the case of &lt;i&gt;Groundwater&lt;/i&gt;, much easier than in the past. Individual papers are usually available on &lt;i&gt;Groundwater's&lt;/i&gt; Early View website (https://ngwa.onlinelibrary.wiley.com/toc/17456584/0/0) several weeks before each issue release, but by compiling these papers into bimonthly issues we add value to the overall &lt;i&gt;Groundwater&lt;/i&gt; package. Even though &lt;i&gt;Groundwater&lt;/i&gt; is no longer printed, as Editor-in-Chief one of my jobs is still to select and order the articles for each collection. I like to lead off and end issues with shorter and lighter articles that are still interesting and pertinent – items like book reviews, media spotlights, and historical notes before and after the meaty research and technical papers. Each issue also includes a section of Society News, highlighting people and events of interest to ou","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":""},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70055","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146159612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling Mechanical Dispersion by Using the Method of Advective Transport Phenomena, a First Step","authors":"Willem J. de Lange","doi":"10.1111/gwat.70050","DOIUrl":"10.1111/gwat.70050","url":null,"abstract":"<p>Mechanical dispersion is driven by a variance in velocity rather than by the concentration gradient in the classical Fickian model. The groundwater community needs a theoretical development for this that offers a practical way to implement it (Konikow 2025). The method of Advective Transport Phenomena (De Lange 2020) describes mechanical dispersion based on the spread of water particles generated at sub-model scale by advective flow through zones with conductivity different from that of the overall aquifer, leading to a new parameter in the dispersive mass flux which is added to the advective mass flux computed at model scale similar to the existing approach in numerical modeling. The new parameter, called dispersive volume shift, is determined only by the traveled distance and the aquifer heterogeneity described by the horizontal and the vertical characteristic length and the log conductivity variance. The dispersive mass flux combines the dispersive volume shift and the concentration difference which is proportional to the traveled distance per time step. Using a spreadsheet model, the longitudinal concentration distribution in a traveling plume is simulated in a homogeneous aquifer and in a heterogeneous aquifer. The latter case shows asymmetry in the plume growth which is not produced by a classical Fickian model. Developments are still needed for application in general numerical modeling.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"202-209"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990970/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146128074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping High-TDS Groundwater Near Impoundments Using Ground and Waterborne Towed Electromagnetics","authors":"Piyoosh Jaysaval,&nbsp;Jonathan N. Thomle,&nbsp;Esteban J. Bowles-Martinez,&nbsp;Rebecca L. Kreuzer,&nbsp;Frederick D. Day-Lewis","doi":"10.1111/gwat.70041","DOIUrl":"10.1111/gwat.70041","url":null,"abstract":"<p>Long-term monitoring at landfills and impoundments containing coal combustion products (CCPs) or other industrial wastes is essential for detecting possible leachate releases to groundwater and mapping contamination plumes. This study evaluates a novel, non-invasive geophysical approach—towed time-domain electromagnetic (TEM) surveys—for non-invasive and rapid assessment of groundwater quality near landfills and impoundments that have the potential to release plumes with higher total dissolved solids (TDS) than groundwater. CCPs are one such example where releases can have relatively high sulfate, sodium, and/or calcium concentrations resulting in high TDS and, therefore, high electrical conductivity. This makes electromagnetic (EM) methods suitable for their detection and monitoring. Recent advancements in TEM technology enable efficient subsurface imaging over extensive areas using antennas towed by vehicles on land or boats on water bodies. TEM surveys provide valuable information about overburden thickness, geological structures, lithology, and pore-fluid TDS. We conducted integrated ground-based and waterborne TEM surveys at a CCP complex adjacent to a river in the eastern United States. Despite challenging site conditions, including railroad tracks, high-voltage power lines, and power-generation infrastructure, high-quality TEM data were collected. Over 20 line-km of data were acquired and inverted using laterally constrained two-dimensional (2D) and spatially constrained three-dimensional (3D) inversions. Results successfully delineated geological boundaries and identified conductive anomalies consistent with elevated TDS indicative of potential leachate plumes. Geophysical interpretations agreed well with water-quality data from nearby monitoring wells. This work highlights the effectiveness of integrated ground-based and floating TEM surveys for high-resolution characterization around CCP impoundments.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"177-188"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145859705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Teach Me How to PyCap: A High-Capacity Well Decision Support Tool Using Analytical Solutions in Python","authors":"Michael N. Fienen,&nbsp;Aaron H. Pruitt,&nbsp;Howard W. Reeves","doi":"10.1111/gwat.70046","DOIUrl":"10.1111/gwat.70046","url":null,"abstract":"<p>Regulatory agencies in humid temperate environments rely on timely evaluations of streamflow depletion and drawdown to protect aquatic ecosystems and existing water users. Numerical models offer detailed insights, but their complexity and time demands often preclude their practical use in rapid decision-making. We present pycap-dss, an open-source Python package that implements a suite of analytical solutions for estimating streamflow depletion and drawdown. The tool supports superposition of multiple wells and time-varying pumping, enabling cumulative impact assessments in situations with multiple wells and streams. The software is modular and extensible, allowing users to interchange solutions or add new analytical methods. A YAML-based configuration supports batch processing of multiple wells, and an optional AnalysisProject class facilitates integration with regulatory workflows. Rigorous unit and regression testing ensures computational reliability, and continuous integration supports ongoing development. We demonstrate deterministic examples of drawdown where multiple solutions are readily compared and streamflow depletion with multiple wells in the Central Sands region of Wisconsin. We also show the value of Monte Carlo analyses of streamflow depletion in the same Central Sands example, leveraging computational efficiency to evaluate the uncertainty of individual and cumulative streamflow depletion calculations from over 200 high-capacity wells.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"223-234"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990963/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Underground Hydromusicology: Subjective Interpretations of Groundwater-Inspired Electronic Music","authors":"Luka Vucinic,&nbsp;Fatima Ajia","doi":"10.1111/gwat.70053","DOIUrl":"https://doi.org/10.1111/gwat.70053","url":null,"abstract":"","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"148-149"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147562236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Potential of Horizontal Wells for Aquifer Storage and Recovery in Saline Aquifers","authors":"Simon Kreipl,&nbsp;Mark Bakker,&nbsp;Boris M. van Breukelen","doi":"10.1111/gwat.70054","DOIUrl":"10.1111/gwat.70054","url":null,"abstract":"<p>Aquifer Storage and Recovery (ASR) is a managed aquifer recharge method where water is injected and later extracted using wells. In saline aquifers, ASR performance is often limited by dispersive mixing, which creates a transition zone at the edge of the injected freshwater and buoyancy-driven flow, which causes the freshwater to rise and deform during storage—both reducing recovery efficiency. This study investigates whether horizontal wells can improve ASR performance in saline, low-transmissivity aquifers by achieving acceptable recovery efficiencies and outperforming conventional vertical wells. Three configurations were evaluated numerically with MODFLOW 6: a horizontal well, a fully penetrating vertical well, and a dual well system with a fully penetrating injection well and a partially penetrating extraction well. Models were tested on a large set of parameter combinations from Latin Hypercube Sampling, targeting conditions where vertical wells perform poorly. The horizontal well generally achieved higher recovery efficiencies, with a median of 45% after five ASR cycles, compared to 6% and 16% for the fully and partially penetrating vertical wells. Its advantage was greatest under strong buoyancy conditions, where vertical wells failed to recover any freshwater. While dispersive mixing reduced horizontal well performance by causing earlier saltwater breakthrough, it improved vertical well recovery by stabilizing the injected freshwater. In conclusion, horizontal wells are promising for ASR when hydraulic conditions require multiple vertical wells and when buoyancy-driven flow significantly limits vertical well performance.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"161-176"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12990971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147313661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-Quantitative Direct-Push Data Can Improve Contaminant Delineation and Mass Discharge in Groundwater","authors":"Anton Bøllingtoft,&nbsp;Wolfgang Nowak,&nbsp;Poul L. Bjerg,&nbsp;Gro Lilbæk,&nbsp;Anders G. Christensen,&nbsp;Mads Troldborg","doi":"10.1111/gwat.70034","DOIUrl":"10.1111/gwat.70034","url":null,"abstract":"<p>Reliable mapping and delineation of contaminant plumes and accurate estimation of contaminant mass discharge (CMD) are critical for groundwater risk assessment and planning of remedial actions at contaminated sites. However, traditional interpolation methods are often challenged by low-density sampling resulting in improper plume delineation. This study introduces a probabilistic censoring method that enhances geostatistical interpolation by incorporating comparably cheap, high-resolution, but semi-quantitative data collected from direct push-probes in the subsurface. The method converts halogen-specific detector signals into binary presence–absence indicators, which are interpolated using indicator kriging to generate a probability field of contaminant distribution. The probability field is then used to censor a spatial concentration field derived from traditional groundwater sampling, retaining interpolated concentration values only in areas where contamination is likely. We apply the method to a site contaminated with chlorinated solvents using two datasets with different sampling densities. Results show that, using our new method, plume fringes became more clearly defined and the total area with low concentrations (&lt;10 μg L⁻¹) increased by 41–85%. CMD estimates were reduced by 13–18%, while relative uncertainty remained largely unchanged. The method integrates seamlessly with traditional interpolation methods and our censoring workflow can be applied to other forms of direct-push data (e.g., relative permeability). As such, the framework offers a useful method for incorporating semi-quantitative field measurements into concentration interpolation and CMD estimation at contaminated sites.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"64 2","pages":"189-201"},"PeriodicalIF":2.0,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145566835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}