Groundwater最新文献

{"title":"Comparison of NMR-Derived Hydraulic Conductivity with Various Hydraulic Testing Methods","authors":"Chenxi Wang,&nbsp;Colby M. Steelman,&nbsp;Zeren Ning,&nbsp;David O. Walsh,&nbsp;Walter A. Illman","doi":"10.1111/gwat.70016","DOIUrl":"10.1111/gwat.70016","url":null,"abstract":"<p>Borehole nuclear magnetic resonance (NMR) can be used to estimate the hydraulic conductivity (<i>K</i>) of unconsolidated materials. Various petrophysical models have been developed to predict <i>K</i> based on NMR response, with considerable efforts on optimizing site-specific constants. In this study, we assessed the utility of NMR logs to estimate <i>K</i> within highly heterogeneous glaciofluvial deposits by comparing them with <i>K</i> measurements from three types of co-located hydraulic testing methods, including permeameter, multi-level slug, and direct-push hydraulic profiling tool (HPT) logging tests. Four NMR models, including Schlumberger-Doll Research (SDR), Seevers, Sum-of-Echoes (SOE), and Kozeny-Godefroy (KGM), were applied to construct <i>K</i> profiles at four locations with model constants optimized using permeameter-based <i>K</i>. Model constants suitable for glaciofluvial deposits were provided. Results showed that NMR logging can provide reliable <i>K</i> estimates for interbedded layers of sand/gravel, silt, and clay. Through cross-hole comparison of NMR-derived <i>K</i> profiles, the trends and magnitudes of <i>K</i> for aquifers/aquitards were readily mapped. Quantitatively, the NMR-derived <i>K</i> coincided with hydraulic-testing <i>K</i>, with optimal model fits within one order of magnitude. We noticed that (1) Seevers performed similarly but no better than SDR in predicting permeameter and slug testing measurements; (2) SOE yielded slightly better predictions than SDR; (3) the removal of porosity in SDR did not deteriorate its prediction, and the optimized SDR constant resembled the literature-based values for glacial deposits; and (4) KGM yielded the optimal fits with slug-based <i>K</i>, demonstrating its reliable performance. Lastly, we made recommendations on selecting suitable petrophysical models.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"713-724"},"PeriodicalIF":2.0,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145014894","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":"Cross-Sectional Models of Groundwater Flow: Review and Correction for Transverse Flow","authors":"Amin Gholami,&nbsp;Amir Jazayeri,&nbsp;Adrian D. Werner","doi":"10.1111/gwat.70017","DOIUrl":"10.1111/gwat.70017","url":null,"abstract":"<p>Cross-sectional (2D) groundwater models are commonly applied to simulate complex processes that are challenging to capture using the coarse grids of 3D regional-scale models. 2D models are often extracted from 3D models for this purpose. However, translating groundwater properties from 3D to 2D models so that regional flow patterns are preserved poses several challenges. A methodology is presented here to maximize agreement between the heads of 2D and 3D groundwater models, considering MODFLOW models with rectilinear grids. This includes careful averaging of hydraulic properties and stresses from the 3D model to create commensurate properties and stresses in cross section. The approach was evaluated by examining the statistical match of transient heads within 10 cross sections extracted from a 3D model of the Limestone Coast (Australia). Concordance between 2D and 3D models was generally poor but was improved by incorporating lateral flow as inflows/outflows in 2D models. Lateral flows required inputs from the 3D model, which limits the application of 2D models as independent predictive tools. Pumping in the 3D model was redistributed to neighboring cells to reduce errors in the 2D model that arise from the limited capability to simulate pumping effects. Although pumping redistribution led to minimal improvement for the case study model, simpler modeling scenarios with more intense, localized pumping showed substantially better head matches between 2D and 3D models when pumping redistribution was applied. The methodology for creating cross-sectional models offered in this article provides relatively simple steps for creating 2D models that are consistent with 3D parent models, although further work is needed to develop a methodology for 2D models that are oblique to 3D model grids.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"752-763"},"PeriodicalIF":2.0,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144994797","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":"Arsenic Contamination in Groundwater of the Bengal Basin: The Largest Mass Poisoning in Human History","authors":"Priyanka Sharma,&nbsp;Kaushik Mitra","doi":"10.1111/gwat.70015","DOIUrl":"10.1111/gwat.70015","url":null,"abstract":"","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"669-671"},"PeriodicalIF":2.0,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062853","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":"Groundwater Potential Mapping: A Misused and Dubious Concept","authors":"Kenneth R. Bradbury","doi":"10.1111/gwat.70013","DOIUrl":"10.1111/gwat.70013","url":null,"abstract":"&lt;p&gt;To most hydrogeologists, the term &lt;i&gt;groundwater potential&lt;/i&gt; is synonymous with hydraulic head or fluid potential energy, as classically defined by Hubbert (&lt;span&gt;1940&lt;/span&gt;) and discussed in numerous hydrogeology texts (e.g., Freeze and Cherry &lt;span&gt;1979&lt;/span&gt;). It follows that a groundwater potential map is a map of an energy surface such as a potentiometric surface or water table. However, this term has recently taken on a new and confusing meaning for resource maps of uncertain and often dubious value.&lt;/p&gt;&lt;p&gt;Over the past few years &lt;i&gt;Groundwater&lt;/i&gt; has received increasing numbers of manuscripts focused on either “groundwater potential” or “groundwater potential mapping”. Typically, such manuscripts use geographic information systems (GIS) or other overlay mapping approaches to generate qualitative maps of “groundwater potential” over areas of local to national scales. The manuscripts, and included maps, usually share a common problem—they fail to define “groundwater potential” or how their definition differs from the common quantitative hydrogeological definition. Almost universally the product of these studies is a subjective map, rating groundwater potential from “very low” to “very high” over a region of interest. The general meaning of potential in these studies seems to be “possible availability for some use” although that use is rarely identified. It is often unclear whether these maps refer to yield, storage, depth, water quality, ease of well construction, or some other property.&lt;/p&gt;&lt;p&gt;The usual methods of constructing these groundwater potential maps involve overlays of spatial data related to geology, slope, recharge, rainfall, land use, soil type, drainage density, lineaments, and topography. This information is often derived from publicly available remote sensing datasets or regional maps at relatively low cost, making the method particularly attractive in undeveloped areas where field data are likely scarce. Typically, the authors overlay and analyze these datasets using methods ranging from simply GIS stacking to sophisticated statistical models, machine learning algorithms, and hybrid/ensemble models (Thanh et al. &lt;span&gt;2022&lt;/span&gt;). Often there is an attempt at validating the final map, but these validations usually suffer from over-correlation, faulty assumptions, and the absence of any error or uncertainty analyses of the multiple input datasets.&lt;/p&gt;&lt;p&gt;Two recent review papers discuss the methods and pitfalls of groundwater potential mapping. Díaz-Alcaide and Martínez-Santos (&lt;span&gt;2019&lt;/span&gt;) reviewed over 200 papers and state that “…the search revealed neither a universal definition of groundwater potential, nor a standardized method or set of units to measure the outcomes.” They point out that quality assurance is a huge challenge in such studies and that “…only a minority of the groundwater potential maps found in the literature have been adequately checked against ground truth.” Thanh et al. (&lt;span&gt;2022&lt;/span&gt;","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"664-665"},"PeriodicalIF":2.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144983938","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 Recharge in a Fire-Adapted, Semi-Arid Forest: A Watershed Water Balance Approach","authors":"Cole Denver,&nbsp;Abraham E. Springer,&nbsp;Salli F. Dymond,&nbsp;Frances C. O'Donnell","doi":"10.1111/gwat.70011","DOIUrl":"10.1111/gwat.70011","url":null,"abstract":"<p>Climate change induced aridity and Euro-American settlement have altered the historical disturbance and flow regimes of large portions of the ponderosa pine forests of northern Arizona. The increased occurrence of high-severity wildfires due to these changes has led to the establishment of various forest restoration programs to protect the region's forests and their watersheds. In 2014, a paired-watershed monitoring project was implemented to compare the impacts of differing levels of forest thinning to watershed hydrology in seven experimental watersheds nested within the Upper Lake Mary (ULM) watershed in Arizona. This study expands the calibration phase of the ULM paired-watershed by synthesizing historic precipitation, surface runoff, groundwater recharge, soil moisture data, and evapotranspiration (ET) data to perform regression analyses and create a holistic water balance for each watershed. The magnitude and timing of seasonal groundwater recharge events were quantified for the first time in this region using a water table fluctuation method. The results showed that recharge did not occur every year and was heavily dependent (<i>P</i> &lt; 0.05) on total winter season precipitation and snowpack duration. On average, recharge composed 9% of the total water budget when present. The results of this study lay the foundation for a greater understanding of how forest restoration alters northern Arizona's forest hydrology and will provide crucial information that should be used in water policy and water resource decision-making as the region plans for future water availability.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"736-751"},"PeriodicalIF":2.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144850092","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":"Society News","authors":"Mike Price","doi":"10.1111/gwat.70012","DOIUrl":"10.1111/gwat.70012","url":null,"abstract":"","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144850093","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":"A Data-Driven Simplified Nernst Equation for Estimating Reduction Potentials in Groundwater from pH and Temperature","authors":"Gordon Bowman,&nbsp;Gabe Harris,&nbsp;Matthew Kirk,&nbsp;Qusheng Jin","doi":"10.1111/gwat.70010","DOIUrl":"10.1111/gwat.70010","url":null,"abstract":"<p>Reduction potentials of redox couples are fundamental for understanding subsurface geochemistry and guiding water resource exploration and management. Reduction potentials are routinely calculated with the Nernst equation, which requires detailed chemical composition data and complex speciation modeling—factors that limit its application in large-scale or data-limited field settings. To address these limitations, we developed a data-driven simplified Nernst equation that estimates the reduction potentials of individual redox couples using only pH and temperature. By integrating geochemical modeling with a global groundwater chemistry dataset, we demonstrate that pH is the dominant control on redox potential, while temperature and redox species activity play secondary roles. The resulting formulation reduces computational demands while maintaining high-predictive accuracy across diverse groundwater environments. This approach enables rapid and scalable estimation of reduction potentials, supporting applications in geochemical modeling, contaminant transport prediction, and groundwater quality assessments. Furthermore, it offers a thermodynamically grounded yet practical framework for interpreting electron transfer dynamics in natural groundwater systems.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"725-735"},"PeriodicalIF":2.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ngwa.onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.70010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144796495","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":"Cave Diving Documents Spatial and Temporal Water Quality Variability in a Phreatic, Karst Cave System","authors":"Mahnoor Kamal,&nbsp;Patricia Spellman,&nbsp;Sunhye Kim","doi":"10.1111/gwat.70006","DOIUrl":"10.1111/gwat.70006","url":null,"abstract":"<p>Karst aquifers have evolved secondary porosity features that facilitate heterogeneous recharge and groundwater flow dynamics. These dynamics affect the natural spatial and temporal variability of water quality in the aquifer. However, when recharge occurs near urban and agricultural land use that can introduce contamination, the contamination can conflate natural water quality variability, generating convoluted signals in time and space. Most water quality investigations in karst aquifers rely on groundwater sampling at discrete locations such as wells or springs, which do not always capture the magnitude of water quality heterogeneity. Cave diving in phreatic caves can be used to explore this variability by using water quality sensors and discrete water chemistry samples to explore spatial and temporal water quality changes for improved and targeted water resource management. Our study uses cave diving to document the spatial and temporal variation in water quality within a phreatic cave system in the Floridan Aquifer System (FAS), a karst aquifer in northern Florida. We collect continuous 15-s measurements of dissolved oxygen (DO), temperature, pH, and specific conductance along a 1.1 km transect, which intersects multiple cave passages that drain into the primary cave passage. We also collect discrete water chemistry samples in three separate cave passages within the phreatic cave, as well as at the spring vent, to document spatial and seasonal variability in nutrients, organic matter, and major groundwater ions. Our results show that specific conductance, DO, temperature, and pH vary together spatially in consistent ways, which we use to identify cave passages that receive more direct recharge. Spatial and temporal variability across the cave system was most pronounced for NO_<i>x</i>-N (nitrate + nitrite), DO, and dissolved organic carbon, while major ions showed minimal spatial variability but greater temporal variability. Relationships derived between specific conductance and NO_<i>x</i>-N show a positive correlation, while relationships between ions associated with carbonate mineralogy and specific conductance are negatively correlated, which likely reflects the impact of recharge from agricultural land use surrounding the cave system. Our results highlight water quality complexity in phreatic caves and have implications for local water quality restoration efforts, interpreting water quality data collected at a discrete location, and provide guidance for future water quality studies in phreatic cave systems.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"685-703"},"PeriodicalIF":2.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144755502","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":"An Alternative Approach to Acquiring Permeability from Ultrasonic S-Wave","authors":"Guangquan Li,&nbsp;Li Wang,&nbsp;Zhongyuan Liu","doi":"10.1111/gwat.70008","DOIUrl":"10.1111/gwat.70008","url":null,"abstract":"<p>Water interaction between fractures and rock matrix is one of the themes in hydrogeology. Accurate values of Darcy permeability (<i>k</i>_<i>D</i>) of the matrix are desired for better quantification of the water interaction. In contrast to the traditional method using seepage experiments to measure <i>k</i>_<i>D</i> of a rock, this study uses the technique of ultrasonic shear (S-) wave for determining <i>k</i>_<i>D</i> of the rock matrix. From the perspective of waves, Darcy seepage is driven by slow compressional (P-) wave at very low frequencies, and <i>k</i>_<i>D</i> is associated with slow P-wave in the regime of low frequency. Similarly, there is another permeability associated with S-wave, namely, S-wave permeability (<i>k</i>_<i>s</i>). The rock samples are Navajo sandstone and Berea sandstone. Data of the dry sandstones with water are entered into Biot theory for yielding saturated phase velocity (<i>V</i>_<i>s</i>) and the quality factor due to viscous fluid (<i>Q</i>_<i>s</i>). Then, ultrasonically measured <i>V</i>_<i>s</i> and <i>Q</i>_<i>s</i> are fitted with the use of the model output. For Navajo sandstone, low-frequency <i>k</i>_<i>s</i> appears to be 0.107–0.115 darcy, surprisingly close to <i>k</i>_<i>D</i> of 0.1 darcy. For Berea sandstone, low-frequency <i>k</i>_<i>s</i> turns out to be 0.081 darcy, also consistent with <i>k</i>_<i>D</i> of 0.075 darcy. The success robustly shows that Biot theory is applicable to S-wave in isotropic rock free of fractures. More importantly, the comparability between low-frequency <i>k</i>_<i>s</i> and <i>k</i>_<i>D</i> demonstrates that ultrasonic S-wave is an alternative approach to acquiring <i>k</i>_<i>D</i> of the matrix.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"704-712"},"PeriodicalIF":2.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144710393","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":"Fundamentals of Groundwater, 2nd Edition","authors":"Alan E. Fryar","doi":"10.1111/gwat.70009","DOIUrl":"10.1111/gwat.70009","url":null,"abstract":"","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"63 5","pages":"667-668"},"PeriodicalIF":2.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062667","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}