Groundwater最新文献

{"title":"From the Mental to the Conceptual Model: The Challenge of Teaching Hydrogeology in the Field","authors":"Joaquin Jimenez-Martinez","doi":"10.1111/gwat.13355","DOIUrl":"10.1111/gwat.13355","url":null,"abstract":"<p>Field-based learning in hydrogeology enables students to develop their understanding and application of practical methodologies, and to enhance many of the generic skills (e.g., teamwork, problem-solving). However, teaching and learning hydrogeology in general, and especially in the field, presents cognitive difficulties, such as the diversity in student education and experience, the hidden nature of water movement and transport of chemicals, and the preexisting students' mental models of the subsurface, in particular. At any given experimental or teaching site there is only one reality for which lecturers can have an approximate conceptual model, including aquifer(s) geometry and functioning (e.g., flow direction). However, students' preconceptions (i.e., mental model), in some cases misconceptions, influence not only their outcome from the learning strategy designed, but also the conceptual model expression (i.e., flow chart, block diagram, or similar) for the study area or site. In practice, two general “teaching challenges” are identified to enable students' transition from the mental to the conceptual model: (1) identify and dispel any prior misconceptions and (2) show how to go from the partial information to the integration of new information for the development of the conceptual model. The inclusion of specific prior-to-field lessons in the classroom is recommended and in general, done. However, introducing a prior-to-field survey to learn about students' backgrounds, and methodologies for the development and expression of hydrogeological conceptual models and for testing multiple plausible conceptual models will help students transition from the mental to the conceptual model.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"61 6","pages":"768-771"},"PeriodicalIF":2.6,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.13355","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41143201","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":"Continental Scale Hydrostratigraphy: Comparing Geologically Informed Data Products to Analytical Solutions","authors":"Jackson S. Swilley,&nbsp;Danielle Tijerina-Kreuzer,&nbsp;Hoang V. Tran,&nbsp;Jun Zhang,&nbsp;Chen Yang,&nbsp;Laura E. Condon,&nbsp;Reed M. Maxwell","doi":"10.1111/gwat.13354","DOIUrl":"10.1111/gwat.13354","url":null,"abstract":"<p>This study synthesizes two different methods for estimating hydraulic conductivity (K) at large scales. We derive analytical approaches that estimate K and apply them to the contiguous United States. We then compare these analytical approaches to three-dimensional, national gridded K data products and three transmissivity (T) data products developed from publicly available sources. We evaluate these data products using multiple approaches: comparing their statistics qualitatively and quantitatively and with hydrologic model simulations. Some of these datasets were used as inputs for an integrated hydrologic model of the Upper Colorado River Basin and the comparison of the results with observations was used to further evaluate the K data products. Simulated average daily streamflow was compared to daily flow data from 10 USGS stream gages in the domain, and annually averaged simulated groundwater depths are compared to observations from nearly 2000 monitoring wells. We find streamflow predictions from analytically informed simulations to be similar in relative bias and Spearman's rho to the geologically informed simulations. <i>R</i>-squared values for groundwater depth predictions are close between the best performing analytically and geologically informed simulations at 0.68 and 0.70 respectively, with RMSE values under 10 m. We also show that the analytical approach derived by this study produces estimates of K that are similar in spatial distribution, standard deviation, mean value, and modeling performance to geologically-informed estimates. The results of this work are used to inform a follow-on study that tests additional data-driven approaches in multiple basins within the contiguous United States.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 1","pages":"75-92"},"PeriodicalIF":2.6,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.13354","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10260724","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":"An Introduction to Solute Transport in Heterogeneous Geologic Media","authors":"Mohamad Reza Soltanian","doi":"10.1111/gwat.13353","DOIUrl":"10.1111/gwat.13353","url":null,"abstract":"","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 2","pages":"172-173"},"PeriodicalIF":2.6,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135396435","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":"Coastal Groundwater-Dependent Ecosystems are Falling Through Policy Gaps","authors":"Madeleine Dyring,&nbsp;Melissa M. Rohde,&nbsp;Ray Froend,&nbsp;Harald Hofmann","doi":"10.1111/gwat.13352","DOIUrl":"10.1111/gwat.13352","url":null,"abstract":"<p>Coastal groundwater-dependent ecosystems (GDEs), such as wetlands, estuaries and nearshore marine habitats, are biodiversity hotspots that provide valuable ecosystem services to society. However, coastal groundwater and associated ecosystems are under threat from groundwater exploitation and depletion, as well as climate change impacts from sea-level rise and extreme flood and drought events. Despite many well-intentioned policies focused on sustainable groundwater use and species protection, coastal GDEs are falling through gaps generated by siloed policies and as a result, are declining in extent and ecological function. This study summarized then examined policies related to the management of coastal groundwater and connected ecosystems in two key case study areas: Queensland (Australia) and California (USA). Despite both areas being regarded as having progressive groundwater policy, our analysis revealed three universal policy gaps, including (1) a lack of recognition of the underlying groundwater system, (2) fragmented policies and complex governance structures that limit coordination, and (3) inadequate guidance for coastal GDE management. Overall, our analysis revealed that coastal GDE conservation relied heavily on inclusion within protected areas or was motivated by species recovery, meaning supporting groundwater systems remained underprotected and outside the remit of conservation efforts. To close these gaps, we consider the adoption of ecosystem-based management principles to foster integrated governance between disparate agencies and consider management tools that bridge traditional conservation realms. Our findings advocate for comprehensive policy frameworks that holistically address the complexities of coastal GDEs across the land-sea continuum to foster their long-term sustainability and conservation.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 2","pages":"184-194"},"PeriodicalIF":2.6,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.13352","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10211157","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":"NGWA News","authors":"","doi":"10.1111/gwat.13346","DOIUrl":"10.1111/gwat.13346","url":null,"abstract":"Matthew “Matt” W. Becker, Ph.D., has been selected as the 2024 Darcy Distinguished Lecturer by NGWA and The Groundwater Foundation. Becker is currently the Conrey Chair in hydrogeology and professor of Earth sciences at California State University, Long Beach, and has previously worked with NASA, Los Alamos National Laboratory, the U.S. Geological Survey, and the University at Buffalo. Becker, who specializes in the research of fluid flow in complex subsurface environments, will be presenting two lectures throughout the year—“Fiber Optic Distributed Sensing as a Window on Subsurface Flow” and “How Groundwater Impacts the People and Ecosystems of the South Pacific Islands.” “I’ve wondered my whole career what it would be like to be the Darcy Lecturer so I’m excited and grateful for the opportunity,” Becker says. “The Darcy lecture is about connecting people and ideas. My goal for this coming year is to help develop new networks for groundwater scientists around the globe.” In his role as Darcy Distinguished Lecturer, Becker will be traveling throughout 2024 presenting his lecture at universities and groundwater industry events across the country and abroad. Becker earned his Ph.D. and M.S. degrees in civil engineering from the University of Texas and a B.S. degree in geology from Michigan State University. The Darcy Distinguished Lecture is named for Henry Darcy of France for his 1856 investigations that established the physical principle upon which modern groundwater hydrogeology is based. Additional financing for the award is provided by the environmental consulting firms S.S. Papadopulos & Associates Inc. and Woodard & Curran Inc. For more information about the Darcy Lecture series, visit www.ngwa.org/events-and-education/groundwaterlecture-series.","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"61 5","pages":"609"},"PeriodicalIF":2.6,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10180094","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":"MODFLOW as a Configurable Multi-Model Hydrologic Simulator","authors":"Christian D. Langevin,&nbsp;Joseph D. Hughes,&nbsp;Alden M. Provost,&nbsp;Martijn J. Russcher,&nbsp;Sorab Panday","doi":"10.1111/gwat.13351","DOIUrl":"10.1111/gwat.13351","url":null,"abstract":"<p>MODFLOW 6 is the latest in a line of six “core” versions of MODFLOW released by the U.S. Geological Survey. The MODFLOW 6 architecture supports incorporation of additional hydrologic processes, in addition to groundwater flow, and allows interaction between processes. The architecture supports multiple model instances and multiple types of models within a single simulation, a flexible approach to formulating and solving the equations that represent hydrologic processes, and recent advances in interoperability, which allow MODFLOW to be accessed and controlled by external programs. The present version of MODFLOW 6 consolidates popular capabilities available in MODFLOW variants, such as the unstructured grid support in MODFLOW-USG, the Newton-Raphson formulation in MODFLOW-NWT, and the support for partitioned stress boundaries in MODFLOW-CDSS. The flexible multi-model capability allows users to configure MODFLOW 6 simulations to represent the local-grid refinement (LGR) capabilities available in MODFLOW-LGR, the multi-species transport capabilities in MT3DMS, and the coupled variable-density capabilities available in SEAWAT. This paper provides a new, holistic and integrated overview of simulation capabilities made possible by the MODFLOW 6 architecture, and describes how ongoing and future development can take advantage of the program architecture to integrate new capabilities in a way that is minimally invasive and automatically compatible with the existing MODFLOW 6 code.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 1","pages":"111-123"},"PeriodicalIF":2.6,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.13351","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10238563","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":"A Novel Semi-Analytical Solution of Over-Damped Slug Test in a Three-Layered Aquifer System","authors":"Mengxiong Cao,&nbsp;Zhang Wen,&nbsp;Gang Chen,&nbsp;Cheng Hu,&nbsp;Qi Zhu,&nbsp;Hamza Jakada","doi":"10.1111/gwat.13350","DOIUrl":"10.1111/gwat.13350","url":null,"abstract":"<p>The slug test has been commonly used to estimate aquifer parameters. Previous studies on the slug test mainly focused on a single-layer aquifer. However, understanding the interaction between layers is particularly important when assessing aquifer parameters under certain circumstances. In this study, a new semi-analytical model on transient flow in a three-layered aquifer system with a partially penetrating well was developed for the slug test. The proposed model was solved using the Laplace transform method and the Goldstein-Weber transform method, where the semi-analytical solution for the model was obtained. The drawdowns of the proposed model were analyzed to understand the impacts of the different parameters on the drawdowns in a three-layered aquifer system. The results indicated that groundwater interactions between the layers have a significant impact on the slug test. In addition, a shorter and deeper well screen as well as a greater permeability ratio between the layers creates a greater interface flow between them, leading to a higher drawdown in the slug test. Finally, a slug test in a three-layered aquifer system was conducted in our laboratory to validate the new model, which indicated that the proposed model performed better in the interpretation of the experimental data than a previous model proposed by Hyder et al. (1994). We also proposed an empirical relationship to qualitatively identify the errors in the application of single-layer model for the analysis of response data in a three-layered aquifer system.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 3","pages":"417-426"},"PeriodicalIF":2.6,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10210614","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":"Benefits and Cautions in Data Assimilation Strategies: An Example of Modeling Groundwater Recharge","authors":"Allen M. Shapiro,&nbsp;Frederick D. Day-Lewis","doi":"10.1111/gwat.13349","DOIUrl":"10.1111/gwat.13349","url":null,"abstract":"<p>Assimilating recent observations improves model outcomes for real-time assessments of groundwater processes. This is demonstrated in estimating time-varying recharge to a shallow fractured-rock aquifer in response to precipitation. Results from estimating the time-varying water-table altitude (<i>h</i>) and recharge, and their error covariances, are compared for forecasting, filtering, and fixed-lag smoothing (FLS), which are implemented using the Kalman Filter as applied to a data-driven, mechanistic model of recharge. Forecasting uses past observations to predict future states and is the current paradigm in most groundwater modeling investigations; filtering assimilates observations up to the current time to estimate current states; and FLS estimates states following a time lag over which additional observations are collected. Results for forecasting yield a large error covariance relative to the magnitude of the expected recharge. With assimilating recent observations of <i>h</i>, filtering and FLS produce estimates of recharge that better represent time-varying observations of <i>h</i> and reduce uncertainty in comparison to forecasting. Although model outcomes from applying data assimilation through filtering or FLS reduce model uncertainty, they are not necessarily mass conservative, whereas forecasting outcomes are mass conservative. Mass conservative outcomes from forecasting are not necessarily more accurate, because process errors are inherent in any model. Improvements in estimating real-time groundwater conditions that better represent observations need to be weighed for the model application against outcomes with inherent process deficiencies. Results from data assimilation strategies discussed in this investigation are anticipated to be relevant to other groundwater processes models where system states are sensitive to system inputs.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 3","pages":"405-416"},"PeriodicalIF":2.6,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10292516","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":"Performance of Gradient and Gradient-Free Optimizers in Transient Hydraulic Tomography","authors":"Syam Chintala,&nbsp;B.V.N. P. Kambhammettu,&nbsp;T. S. Harmya","doi":"10.1111/gwat.13347","DOIUrl":"10.1111/gwat.13347","url":null,"abstract":"<p>Sub-surface characterization in fractured aquifers is challenging due to the co-existence of contrasting materials namely matrix and fractures. Transient hydraulic tomography (THT) is proved to be an efficient and robust technique to estimate hydraulic (<i>K</i>_<i>m</i>, <i>K</i>_<i>f</i>) and storage (<i>S</i>_<i>m</i>, <i>S</i>_<i>f</i>) properties in such complex hydrogeologic settings. However, performance of THT is governed by data quality and optimization technique used in inversion. We assessed the performance of gradient and gradient-free optimizers with THT inversion. Laboratory experiments were performed on a two-dimensional, granite rock (80 cm × 45 cm × 5 cm) with known fracture pattern. Cross-hole pumping experiments were conducted at 10 ports (located on fractures), and time-drawdown responses were monitored at 25 ports (located on matrix and fractures). Pumping ports were ranked based on weighted signal-to-noise ratio (SNR) computed at each observation port. Noise-free, good quality (SNR &gt; 100) datasets were inverted using Levenberg–Marquardt: LM (gradient) and Nelder–Mead: NM (gradient-free) methods. All simulations were performed using a coupled simulation-optimization model. Performance of the two optimizers is evaluated by comparing model predictions with observations made at two validation ports that were not used in simulation. Both LM and NM algorithms have broadly captured the preferential flow paths (fracture network) via <i>K</i> and <i>S</i> tomograms, however LM has outperformed NM during validation (<span></span><math>\u0000 <mrow>\u0000 <msubsup>\u0000 <mi>R</mi>\u0000 <mi>LM</mi>\u0000 <mn>2</mn>\u0000 </msubsup>\u0000 <mo>=</mo>\u0000 <mn>0.76</mn>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mtext>RMSE</mtext>\u0000 <mi>LM</mi>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>1.75</mn>\u0000 <mspace></mspace>\u0000 <mi>cm</mi>\u0000 <mo>,</mo>\u0000 <msubsup>\u0000 <mi>R</mi>\u0000 <mi>NM</mi>\u0000 <mn>2</mn>\u0000 </msubsup>\u0000 <mo>=</mo>\u0000 <mn>0.73</mn>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mtext>RMSE</mtext>\u0000 <mi>NM</mi>\u0000 </msub>\u0000 <mo>=</mo>\u0000 <mn>1.77</mn>\u0000 <mspace></mspace>\u0000 <mi>cm</mi>\u0000 </mrow></math>). Our results conclude that, while method of optimization has a trivial effect on model predictions, exclusion of low quality (SNR ≤ 100) datasets can significantly improve the model performance.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 3","pages":"371-383"},"PeriodicalIF":2.6,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10114306","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":"Evaluation of Hydraulic Conductivity Estimates from Various Approaches with Groundwater Flow Models","authors":"Dongwei Sun,&nbsp;Ning Luo,&nbsp;Aaron Vandenhoff,&nbsp;Wesley McCall,&nbsp;Zhanfeng Zhao,&nbsp;Chenxi Wang,&nbsp;David L. Rudolph,&nbsp;Walter A. Illman","doi":"10.1111/gwat.13348","DOIUrl":"10.1111/gwat.13348","url":null,"abstract":"<p>Significant efforts have been expended for improved characterization of hydraulic conductivity (<i>K</i>) and specific storage (<i>S</i>_<i>s</i>) to better understand groundwater flow and contaminant transport processes. Conventional methods including grain size analyses (GSA), permeameter, slug, and pumping tests have been utilized extensively, while Direct Push-based Hydraulic Profiling Tool (HPT) surveys have been developed to obtain high-resolution <i>K</i> estimates. Moreover, inverse modeling approaches based on geology-based zonations, and highly parameterized Hydraulic Tomography (HT) have also been advanced to map spatial variations of <i>K</i> and <i>S</i>_<i>s</i> between and beyond boreholes. While different methods are available, it is unclear which one yields <i>K</i> estimates that are most useful for high resolution predictions of groundwater flow. Therefore, the main objective of this study is to evaluate various <i>K</i> estimates at a highly heterogeneous field site obtained with three categories of characterization techniques including: (1) conventional methods (GSA, permeameter, and slug tests); (2) HPT surveys; and (3) inverse modeling based on geology-based zonations and highly parameterized approaches. The performance of each approach is first qualitatively analyzed by comparing <i>K</i> estimates to site geology. Then, steady-state and transient groundwater flow models are employed to quantitatively assess various <i>K</i> estimates by simulating pumping tests not used for parameter estimation. Results reveal that inverse modeling approaches yield the best drawdown predictions under both steady and transient conditions. In contrast, conventional methods and HPT surveys yield biased predictions. Based on our research, it appears that inverse modeling and data fusion are necessary steps in predicting accurate groundwater flow behavior.</p>","PeriodicalId":12866,"journal":{"name":"Groundwater","volume":"62 3","pages":"384-404"},"PeriodicalIF":2.6,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwat.13348","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10218561","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}