Download or read book Comparison of Approaches to Characterize Flow Conditions in Bedrock Wells written by Stephanie Phillips and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Evaluating vertical flow in bedrock wells is important for understanding aquifer hydraulic parameters, and borehole flowmeter methods are critical for analyzing flow in fractured-rock aquifers. Single borehole logging is used to identify active hydraulic zones under ambient and pumping conditions, and crosshole flowmeter logging is used to identify hydraulic connections between boreholes. To identify potential zones of interest for flowmeter logging in fractured rock, first a series of conventional borehole logs are collected. Then, locations for flowmeter logging are selected and data are collected under ambient and stressed conditions to distinguish fracture flow zones. Because flowmeters are limited by their resolution and operational range, tool selection is critical and should be matched to site conditions and project goals. In this study, data were collected in three boreholes in a fractured rock setting in Storrs, Connecticut, to compare three flow logging methods. Prior to flow logging, acoustic- and optical-televiewer, fluid temperature, and conductivity logs were collected in the wells. Flow measurement data were collected under ambient and pumping conditions using spinner, heat-pulse, and electromagnetic flowmeters. Factors for comparing the flow data include the spatial resolution of flow zones, maximum and minimal flow detection rates, and rapidity and ease of data collection and analysis. Fracture transmissivity results of the flow logs were also compared to results from a dissolved oxygen alteration method and a newly designed packer method.
Download or read book A Cross site Comparison of Methods Used for Hydrogeologic Characterization of the Galena Platteville Aquifer in Illinois and Wisconsin with Examples from Selected Superfund Sites written by and published by . This book was released on 2004 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Utilization of the Square Array Earth Resistivity Method for Characterizing Anisotropy in Fractured Sedimentary Rock written by David Yoxtheimer and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured bedrock aquifers are key sources of potable groundwater globally. Therefore it is important to characterize the presence and orientations of subsurface fractures that impact groundwater flow in order to develop, manage and protect these critical water resources. A significant challenge in characterizing groundwater flow in a fractured bedrock aquifer is determining if anisotropic conditions exist. The square array method provides a means to estimate geo-electrical anisotropy, which can be useful when conducting hydrogeologic investigations including mapping fracture orientations, siting water supply wells, conducting source water protection programs, or mapping contaminant plumes. However, this method has not been previously tested to characterize the hydrogeology of folded and fractured carbonate bedrock overlain by conductive layers of soil and epikarst, nor for characterizing shale formations. In this study, the square array method is used to measure the change in electrical resistivity of the subsurface with respect to azimuth at six locations in the Cambrio-Ordovician carbonate bedrock aquifer of Spring Creek watershed and the shale formation underlying the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO), both located within the Appalachian Valley and Ridge Province of central Pennsylvania. The carbonate bedrock aquifer is mantled with residual soils consisting primarily of silt and clay loams of variable thickness (0 to greater than 10 meters) below which occurs an epikarst system that plays a significant role in shallow groundwater flow. The square array is used to characterize the carbonate aquifers bedrock strike- and fracture-related anisotropy and provide estimates of secondary porosity. The results show that the square array apparent resistivity data correlates well with known bedrock structure, in particular the resistivity minima for the deeper measurements (40- and 50-meter a-spacings) are coincident with the northeast-southwest orientation of bedrock strike and/or mapped fractures, where present. In addition, estimates of secondary porosity from the square arrays 40- and 50-meter a-spacings (range of 0.7-4.4% with a mean of 3.1%) generally compare favorably to independent estimates of bedrock structure and secondary porosity from outcrop measurements and groundwater level/streamflow recession data (1-5%). The results of this study demonstrate that the square array method can be used effectively in complex, fractured carbonate bedrock settings to characterize bedrock anisotropy and secondary porosity, which were field-validated based on bedrock outcrop structure and fracture geometry measurements. Previous square array studies have detected anisotropy and estimated secondary porosity in both carbonate and crystalline bedrock, however this research further validates the method by comparing field measurements to the square array data, and thus advances the methods application. Geo-electrical anisotropy associated with inclined bedding planes and fractures in bedrock is often not factored into apparent resistivity results, much less data inversion, which can lead to misleading model results. In particular, the paradox of anisotropy occurs where collinear resistivity data are collected in areas with inclined bedding planes or fractures and longitudinal apparent resistivity is greater than transverse apparent resistivity, which is the converse of when true resistivity values are considered. The SSHCZO study expands critical zone research by evaluating the effects of anisotropy on earth resistivity measurements in a fractured shale bedrock setting using both square and Wenner arrays. The square array can be used to determine the magnitude and orientation of anisotropy, as it is not subject to the paradox of anisotropy, whereas collinear arrays are, including the Wenner array. In fractured shale bedrock the anisotropy effects can be significant, including the paradox of anisotropy, which can lead to significantly inaccurate models if not factored into the input data. In this study the square array was used to evaluate site anisotropy at variable depths, including through the soils and bedrock profile, including fractured, weathered and unweathered bedrock intervals. The square arrays anisotropy coefficient was then factored into apparent resistivity data from strike parallel and perpendicular 2-D Wenner arrays to correct for the paradox of anisotropy. The corrected 2-D resistivity data were then inverted to obtain model results where longitudinal resistivity values were lower than transverse resistivity values, as would be expected. In addition, a series of ten parallel 2-D Wenner arrays were run and used to create pseudo 3-D models of the sites resistivity distribution using anisotropy corrections from the square array data for comparison to 3-D models without this correction. This sequence of steps resulted in a 3-D resistivity model that provided useful insights into shallow groundwater interflow at the SSHCZO site. Ultimately this study provides a method that can be applied to geophysically characterize the groundwater flow mechanisms in the critical zone and allow investigators to design subsurface monitoring programs to further advance hydrologic and hydrogeologic research. The combined results of these studies show the square array can be utilized in fractured carbonate and shale bedrock settings to ascertain geo-electrical anisotropy, which correlates well to bedrock and fracture strike. For the fractured carbonate aquifer the square array was validated to provide reasonable estimates of secondary porosity based on both outcrop fracture measurements and groundwater level recession analysis. In the shale bedrock setting, the square array provided a useful correction factor for the coefficient of anisotropy in 2-D collinear resistivity arrays, which then yielded useful insights into shallow groundwater flow conditions via 3-D modeling developed from the corrected 2-D resistivity arrays.
Download or read book Identification Characterization and Analysis of Hydraulically Conductive Fractures in Granitic Basement Rocks Millville Massachusetts written by F. L. Paillet and published by . This book was released on 1994 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: ... Presents geophysical well-log data and interpretations used to identify and characterize fractures and to analyze fracture distribution and fracture flow at a site in south-central MA; data include borehole wall images, caliper logs that indicate the distribution of fractures in five boreholes located along the axis of the distribution of contaminated wells and flowmeter profiles obtained under ambient hydraulic-head conditions and during injection tests ...
Download or read book Characterization of Ground water Flow Between the Canisteo Mine Pit and Surrounding Aquifers Mesabi Iron Range Minnesota written by Perry M. Jones and published by . This book was released on 2002 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Ground water Discharge from Bedrock Aquifers to the Mississippi and Minnesota Rivers at Three Areas Minneapolis St Paul Area Minnesota written by Michael Schoenberg and published by . This book was released on 1994 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aquifer Characterization Techniques written by Robert G. Maliva and published by Springer. This book was released on 2016-05-26 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of techniques that are available to characterize sedimentary aquifers. Groundwater flow and solute transport are strongly affected by aquifer heterogeneity. Improved aquifer characterization can allow for a better conceptual understanding of aquifer systems, which can lead to more accurate groundwater models and successful water management solutions, such as contaminant remediation and managed aquifer recharge systems. This book has an applied perspective in that it considers the practicality of techniques for actual groundwater management and development projects in terms of costs, technical resources and expertise required, and investigation time. A discussion of the geological causes, types, and scales of aquifer heterogeneity is first provided. Aquifer characterization methods are then discussed, followed by chapters on data upscaling, groundwater modelling, and geostatistics. This book is a must for every practitioner, graduate student, or researcher dealing with aquifer characterization .
Download or read book Enhanced Characterization and Representation of Flow Through Karst Aquifers written by Scott L. Painter and published by American Water Works Association. This book was released on 2006 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research report summaries and details the first year of work on a multi-year karst modeling project organized to develop enhanced groundwater modeling capabilities that can be used to effectively manage karst aquifers. Discussed are the three key considerations for modeling karst systems were identified: representation of conduits in flow models, representation of flow dynamics in conduits, and representation of partially filled conduits and the numerical experiments used to identify the limitations and advantages of the three general representations of conduits within groundwater models. A new dual-conductivity MODFLOW-2000 package (DCM) was developed for testing the dual-conductivity approach. A turbulence model was added, the software was validated using simple benchmark problems, and code documentation was completed. Simultaneous demonstrations showed that the modeling tool can be successfully applied in complex applications.
Download or read book Characterization Modeling Monitoring and Remediation of Fractured Rock written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2021-01-29 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.
Download or read book Rock Fractures and Fluid Flow written by National Research Council and published by National Academies Press. This book was released on 1996-08-27 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding of fluid flow in rock fracturesâ€"a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storageâ€"has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.
Download or read book Water resources Investigations Report written by and published by . This book was released on 2003 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Streamflow depletion by wells written by Paul M. Barlow and published by . This book was released on 2012 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific Investigations Report written by and published by . This book was released on 2004 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Download or read book Standard Handbook for Solid and Hazardous Waste Facility Assessments written by Martin N. Sara and published by CRC Press. This book was released on 1994 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt: This landmark new book sets the standard for planning, performing, and interpreting investigations for solid and hazardous waste sites and selecting appropriate locations for ground-water monitoring. It covers the technical components of assessment monitoring programs that define both the rate and extent of contamination and provide design criteria for aquifer remediation. Technical tools are discussed in detail to provide background techniques such as flow net constructions, cross section instructions, and documentation standards. More than 500 figures and tables illustrate the author's structured holistic program for examining the physical, chemical, and environmental factors of a site for waste disposal. The technical aspects of site assessments regarding contaminated ground-water evaluation and remediation are also covered in detail. Learn the fundamentals of site assessments This classic guide explains the fundamentals of a technical approach to site assessments. It is the principle text used for training EPA regional project managers for Superfund sites. The book uses a practical, step-by-step format to walk you through the following tasks:
Download or read book Lithology and Fracture Characterization from Drilling Investigations in the Mirror Lake Area Grafton County New Hampshire written by Carole D. Johnson and published by . This book was released on 1998 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
