Download or read book An Analysis of Unconfined Ground Water Flow Characteristics Near a Seepage face Boundary written by Matthew Simpson and published by . This book was released on 2003 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quantitative understanding of ground water flow characteristics in unconfined aquifers is important because of the prevalence of abstraction from, and pollution of these systems. The current understanding of ground water flow in unconfined aquifers is limited because of the dominance of horizontal flow modelling strategies used to represent unconfined flow processes. The application of horizontal flow principles leads to an ignorance of seepage-face formation and can not predict the complicated three-dimensional nature of the ground water flow that dominates at the ground water-surface water interface. This study aims to address some of these deficiencies by exploring the true three-dimensional nature of ground water flow including the formation of seepage faces at the ground water-surface water interface using numerical and laboratory techniques. A finite element model for simulating two-dimensional (vertical) variably saturated flow is developed and benchmarked against standard laboratory and field-scale solutions. The numerical features of the finite element model are explored and compared to a simple finite difference formulation. The comparison demonstrates how finite element formulations lead to a broader spatial averaging of material properties and a different method for the representation of specified flux boundaries. A detailed comparison analysis indicates that these differences in the finite element solution lead to an improved approximation to the partial differential equation governing two-dimensional (vertical) variably saturated flow. A laboratory analysis of unconfined ground water flow and associated solute transport characteristics was performed. The analysis focused upon unconfined flow towards a pumping well. The laboratory observations were reliably reproduced using a three-dimensional (axi-symmetric), variably saturated ground water flow model. The model was benchmarked against the ground water flow characteristics such as the seepage-face height and total flow rate. In addition, the model was shown to reliably reproduce the solute transport features such as travel times and streamline distributions. This is the first time that a numerical model has been used to reliably reproduce the solute transport characteristics near a seepage-face boundary where the three-dimensional flow effects are prevalent. The ability to reliably predict solute transport patterns in the seepage-face zone is important since this region is known to support vital microbially facilitated reactions that control nutrient cycling and contaminant attenuation. The three-dimensional travel time distribution near the seepage-face was compared to that predicted using a horizontal flow modelling approach derived from the basic Dupuit-Forchheimer equations. The Dupuit-Forchheimer based model indicated that horizontal flow modelling would under-estimate the total residence time near a seepage-face boundary, thereby introducing a considerable source of error in a solute transport analysis. For this analysis, a new analytical solution for the steady travel time distribution in an unconfined aquifer subject to a single pumping well was derived. The analytical model has identified, for the first time in the hydrogeology literature, the use of the imaginary error function. The imaginary error function is a standard transcendental function and an infinite series approach to evaluate the function was successfully proposed. The two-dimensional (vertical) ground water flow model was extended to handle the case where the flow is driven by density gradients near the ground water-surface water interface. The unsteady, two-dimensional, Galerkin finite element model of density-dependent ground water flow in variably saturated porous media is rigorously presented and partially benchmarked under fully saturated (confined) conditions. The partial benchmarking involved reproducing solutions to the standard Henry salt-water intrusion and the Elder salt-convection problems. The model was used in a standard density-coupled and a new density-uncoupled mode to elucidate the worthiness of the Henry and Elder problems as benchmark standards. A comparison of the coupled and uncoupled solutions indicates that the Henry salt-water intrusion problem has limited worthiness as a benchmark as the patterns of ground water flow are relatively insensitive to density-coupled effects. Alternatively, the Elder problem is completely dependent upon a correct representation of the density-coupled flow and solute transport processes. The coupled versus uncoupled comparison is proposed as a new test of the worthiness of benchmark standards. The Henry salt-water intrusion problem was further analysed in an attempt to alleviate some of the difficulties associated with this benchmark problem. The numerical model was tested against a re-evaluated version of Henry's semi-analytical solution for the coupled solute concentration distribution. The numerical model was used to propose a modified version of the Henry problem where the importance of density-coupled processes was increased. The modified problem was shown to have an improved worthiness as compared to the standard solution. The numerical model results were benchmarked against a new set of semi-analytical results for the modified problem. Certain advantages in using the modified problem as a test case for benchmarking the results of a numerical model of density-dependent ground water flow are identified. A numerical investigation of the patterns of density-driven ground water flow at the ground water-surface water interface was undertaken. The numerical model is shown to produce grid-independent results for a finely discretised domain. The pattern of discharge is controlled, in part, by two parameters. One describes the recharge applied to the aquifer, and the second describes the magnitude of the density differences between the fresh recharging fluid and the saline receiving fluid. The influence of dense intrusions upon the formation of seepage-face boundaries at the ground water-surface water interface under steady-state conditions was also investigated. Dense intrusions are shown to dominate the pattern of ground water flow only under mild recharge conditions, while seepage faces dominate the outflow pattern under strong recharge conditions. Therefore, the formation of seepage-face boundaries and dense intrusions are unlikely to coincide under the conditions examined in this study.

Download or read book Seepage and Groundwater Flow written by K. R. Rushton and published by John Wiley & Sons. This book was released on 1979 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seepage Face Effects in Unsteady Groundwater Flow written by Willard A. Murray and published by . This book was released on 1971 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for Evaluating Ground water Flow Models written by Thomas E. Reilly and published by DIANE Publishing. This book was released on 2004 with total page 37 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 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Isogeometric Analysis written by J. Austin Cottrell and published by John Wiley & Sons. This book was released on 2009-08-11 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: “The authors are the originators of isogeometric analysis, are excellent scientists and good educators. It is very original. There is no other book on this topic.” —René de Borst, Eindhoven University of Technology Written by leading experts in the field and featuring fully integrated colour throughout, Isogeometric Analysis provides a groundbreaking solution for the integration of CAD and FEA technologies. Tom Hughes and his researchers, Austin Cottrell and Yuri Bazilevs, present their pioneering isogeometric approach, which aims to integrate the two techniques of CAD and FEA using precise NURBS geometry in the FEA application. This technology offers the potential to revolutionise automobile, ship and airplane design and analysis by allowing models to be designed, tested and adjusted in one integrative stage. Providing a systematic approach to the topic, the authors begin with a tutorial introducing the foundations of Isogeometric Analysis, before advancing to a comprehensive coverage of the most recent developments in the technique. The authors offer a clear explanation as to how to add isogeometric capabilities to existing finite element computer programs, demonstrating how to implement and use the technology. Detailed programming examples and datasets are included to impart a thorough knowledge and understanding of the material. Provides examples of different applications, showing the reader how to implement isogeometric models Addresses readers on both sides of the CAD/FEA divide Describes Non-Uniform Rational B-Splines (NURBS) basis functions

Download or read book Aspects of Small scale and Large scale Variability in Unconfined Groundwater Flow written by Aly Ibrahim Kadi and published by . This book was released on 1983 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geological Survey Water supply Paper written by and published by . This book was released on 1984 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Geological Survey Water supply Paper written by and published by . This book was released on 1982 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Difference Analysis of Unconfined Groundwater Flow to Well Near Partially Penetrating Rivers written by M. W. Kawecki and published by . This book was released on 1978 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dream Analytical Ground Water Flow Programs written by Stewart Rounds and published by CRC Press. This book was released on 2020-10-29 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Valuable for consultants and regulators...Dream is a useful tool for basic field work, including the first-cut evaluation of remediation design. Ground water professionals will find Dream to be ideal for estimating actual flow conditions when information on aquifer properties is limited. Flow nets, streamline plots, and capture zone maps are easily produced by contouring Dream's output files. Maps of head, drawdown, and ground water velocity are equally simple to create. These provide an uncomplicated method for estimating both direction and magnitude of flow, and the areal extent of the well's influence. This must-have volume is valuable for hydrologists, regulators, ground water professionals, students, professors, and consultants. This work is a valuable teaching tool for principles of subsurface hydrology. It is easy-to-use and illustrates hydrologic concepts, pumping schemes, remediation schemes, etc. The importance of fundamental aquifer properties can be easily explored, at both the graduate and undergraduate levels.

Download or read book The Boundary Element Method Volume 1 written by L. C. Wrobel and published by John Wiley & Sons. This book was released on 2002-04-22 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: The boundary element method (BEM) is a modern numerical techniquewhich has enjoyed increasing popularity over the last two decades,and is now an established alternative to traditional computationalmethods of engineering analysis. The main advantage of the BEM isits unique ability to provide a complete solution in terms ofboundary values only, with substantial savings in modelling effort. This two-volume book set is designed to provide the readers with acomprehensive and up-to-date account of the boundary element methodand its application to solving engineering problems. Each volume isa self-contained book including a substantial amount of materialnot previously covered by other text books on the subject. Volume 1covers applications to heat transfer, acoustics, electrochemistryand fluid mechanics problems, while volume 2 concentrates on solidsand structures, describing applications to elasticity, plasticity,elastodynamics, fracture mechanics and contact analysis. The earlychapters are designed as a teaching text for final yearundergraduate courses. Both volumes reflect the experience of theauthors over a period of more than twenty years of boundary element research. This volume, Applications in Thermo-Fluids and Acoustics, provides acomprehensive presentation of the BEM from fundamentals to advancedengineering applications and encompasses: Steady and transient heat transfer Potential and viscous fluid flows Frequency and time-domain acoustics Corrosion and other electrochemical problems. A unique feature of this book is an in-depth presentation of BEMformulations in all the above fields, including detaileddiscussions of the basic theory, numerical algorithms and practicalengineering applications of the method. Written by an internationally recognised authority in the field,this is essential reading for postgraduates, researchers andpractitioners in civil, mechanical and chemical engineering andapplied mathematics.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1999 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulated Hydrologic Responses of the Quashnet River Stream aquifer System to Proposed Ground water Withdrawals Cape Cod Massachusetts written by Paul M. Barlow and published by . This book was released on 1993 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: ... The purposes of this report are to describe (1) the hydrologic characteristics of the Quashnet River stream aquifer system and (2) the responses of the system to proposed ground water withdrawals simulated by use of a numerical model of ground water flow; these reponses to pumping are assessed in terms of drawdowns in the altitude of the water table, streamflow depletions, and sources of water to the river and the simulated supply well; in this report, the Quashnet river stream aquifer system is defined as that area extending approximately from the Mashpee River on the east to the Coonamessett River on the west and from Nantucket Sound to approximately 1 mile north of Johns Pond; this report is based on ground and surface water data collected during the study and compiled from engineers' reports and USGS ground and surface water data bases; physical characteristics of the Quashnet and Childs Rivers (streamflow, stream velocity, width and depth), surface altitude of Johns Pond, and hydraulic heads within the basin were measured from January 1990 through September 1991 ...

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 Seepage Face Effects in Unsteady Groundwater Flow written by Willard Austin Murray and published by . This book was released on 1971 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrology and Simulation of the Ground water Flow System in Tooele Valley Utah written by P. M. Lambert and published by . This book was released on 1999 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: