Download or read book Improved Numerical Methods for Modeling River Aquifer Interaction written by and published by . This book was released on 2008 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new option for Local Time-Stepping (LTS) was developed to use in conjunction with the multiple-refined-area grid capability of the U.S. Geological Survey's (USGS) groundwater modeling program, MODFLOW-LGR (MF-LGR). The LTS option allows each local, refined-area grid to simulate multiple stress periods within each stress period of a coarser, regional grid. This option is an alternative to the current method of MF-LGR whereby the refined grids are required to have the same stress period and time-step structure as the coarse grid. The MF-LGR method for simulating multiple-refined grids essentially defines each grid as a complete model, then for each coarse grid time-step, iteratively runs each model until the head and flux changes at the interfacing boundaries of the models are less than some specified tolerances. Use of the LTS option is illustrated in two hypothetical test cases consisting of a dual well pumping system and a hydraulically connected stream-aquifer system, and one field application. Each of the hypothetical test cases was simulated with multiple scenarios including an LTS scenario, which combined a monthly stress period for a coarse grid model with a daily stress period for a refined grid model. The other scenarios simulated various combinations of grid spacing and temporal refinement using standard MODFLOW model constructs. The field application simulated an irrigated corridor along the Lower Rio Grande River in New Mexico, with refinement of a small agricultural area in the irrigated corridor. The results from the LTS scenarios for the hypothetical test cases closely replicated the results from the true scenarios in the refined areas of interest. The head errors of the LTS scenarios were much smaller than from the other scenarios in relation to the true solution, and the run times for the LTS models were three to six times faster than the true models for the dual well and stream-aquifer test cases, respectively. The results of the field application show that better estimates of daily stream leakage can be made with the LTS simulation, thereby improving the efficiency of daily operations for an agricultural irrigation system. ACKNOWLEDGEMENTSThe authors appreciatively acknowledge support for Sue Tillery provided by Sandia National Laboratories' through a Campus Executive Laboratory Directed Research and Development (LDRD) research project. Funding for this study was provided by %3C???. S. Tillery is funded by Sandia National Laboratories' through an Excellence in Engineering Fellowship Laboratory> Directed Research and Development (LDRD) research project.

Download or read book Efficient Numerical Methods and Information Processing Techniques for Modeling Hydro and Environmental Systems written by Reinhard Hinkelmann and published by Springer Science & Business Media. This book was released on 2006-08-10 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulation models have become indispensable in hydro- and environmental sciences and engineering. This monograph presents a general introduction to numerical simulation in environment water, based on the solution of the equations for groundwater flow and transport processes, for multiphase and multicomponent flow and transport processes in the subsurface as well as for flow and transport processes in surface waters. It displays in detail the state of the art of discretization and stabilization methods (e.g. finite-difference, finite-element, and finite-volume methods), parallel methods, and adaptive methods as well as fast solvers, with particular focus on explaining the interactions of the different methods. The book gives a brief overview of various information-processing techniques and demonstrates the interactions of the numerical methods with the information-processing techniques, in order to achieve efficient numerical simulations for a wide range of applications in environment water.

Download or read book Aquifer Modeling by Numerical Methods Applied to an Arizona Groundwater Basin written by Graham E. Fogg and published by . This book was released on 1979 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Groundwater Hydrology written by K. R. Rushton and published by John Wiley & Sons. This book was released on 2004-02-06 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Groundwater is a vital source of water throughout the world. As the number of groundwater investigations increase, it is important to understand how to develop comprehensive quantified conceptual models and appreciate the basis of analytical solutions or numerical methods of modelling groundwater flow. Groundwater Hydrology: Conceptual and Computational Models describes advances in both conceptual and numerical modelling. It gives insights into the interpretation of field information, the development of conceptual models, the use of computational models based on analytical and numerical techniques, the assessment of the adequacy of models, and the use of computational models for predictive purposes. It focuses on the study of groundwater flow problems and a thorough analysis of real practical field case studies. It is divided into three parts: * Part I deals with the basic principles, including a summary of mathematical descriptions of groundwater flow, recharge estimation using soil moisture balance techniques, and extensive studies of groundwater-surface water interactions. * Part II focuses on the concepts and methods of analysis for radial flow to boreholes including topics such as large diameter wells, multi-layered aquifer systems, aquitard storage and the prediction of long-term yield. * Part III examines regional groundwater flow including situations when vertical flows are important or transmissivities change with saturated depth. Suitable for practising engineers, hydrogeologists, researchers in groundwater and irrigation, mathematical modellers, groundwater scientists, and water resource specialists. Appropriate for upper level undergraduates and MSc students in Departments of Civil Engineering, Environmental Engineering, Earth Science and Physical Geography. It would also be useful for hydrologists, civil engineers, physical geographers, agricultural engineers, consultancy firms involved in water resource projects, and overseas development workers.

Download or read book Groundwater Resources Modelling written by M. G. Shepley and published by Geological Society of London. This book was released on 2012 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: The UK is a country with over 150 years of widespread exploitation of its principal aquifers for public water supply. Increasing demands, greater awareness of environmental pressures and more exacting legislation has heightened the need for quantitative models to predict the impacts of groundwater use. In the UK this has culminated in a unique national, regulator-led programme for England and Wales to develop conceptual and numerical models of the principal bedrock aquifers. The outcomes of this programme will be of interest to the international hydrogeological community, particularly as international legislation such as the European Water Framework Directive requires management of water issues across administrative boundaries with a varied cast of stakeholders. The collection of papers provides a contrast between practitioner- and research-based approaches to assess and predict the anthropogenic impacts and environmental pressures.

Download or read book Advanced Tools and Models to Improve River Basin Management in Europe in the Context of Climate Change written by Michael Finkel and published by IWA Publishing. This book was released on 2010-08-14 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Tools and Models to Improve River Basin Management in Europe in the Context of Climate Change - AquaTerra has developed from an integrated project of the 6th EU RTD Framework Programme that aims to provide the scientific basis for an improved river basin management through a better understanding of the river-sediment-soil-groundwater system as a whole, by integrating both natural and socio-economics aspects at different temporal and spatial scales. This book aims: To provide better understanding of the river-sediment-soil-groundwater system at various temporal and spatial scales To relate expected climate alterations to changes in deposition, mobility and distribution of pollutants in European river basins To provide the scientific basis for improved river basin management To introduce novel tools for water and soil quality monitoring To show the necessity of integrated modelling frameworks for impact evaluation of pollution as well as climate and land-use changes for definition of long-term management schemes The work illustrates the dynamic behavior of the pathway of pollutants in soils, groundwater, surface water and sediments. It highlights the fundamental importance of integrating knowledge from several combined disciplines on various environmental compartments in order to understand the large number of processes that govern pollutant input, transport and turnover. Results shows that a significant step forward has been made in the development new analytical methods and of process-based numerical models that are capable of making predictions of likely trends and environmental changes to be expected in the near or distant future at the basin-scale. These models can be used e.g. to generate hydrologic scenarios based on climate models and to simulate pollutant distribution and turnover rates from decades to millennia.

Download or read book NBS Special Publication written by and published by . This book was released on 1980 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modelling of Hydrodynamics for Water Resources written by Pilar Garcia Navarro and published by CRC Press. This book was released on 2007-11-01 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overland flow modelling has been an active field of research for some years, but developments in numerical methods and computational resources have recently accelerated progress, producing models for different geometries and types of flows, such as simulations of canal and river networks. Flow in canals has traditionally been described using one-dimensional, depth-averaged, shallow water models; but a variety of simulation techniques now facilitate the management of hydrodynamic systems, providing models which incorporate complex geometry and diverse flows. Much effort has gone into elaborating canal operational rules based on decision support systems, with the dual aim of assuring water delivery and meeting flow control constraints. In natural water courses, water management problems are associated with the need to meet quality standards. Numerical modelling of advection-diffusion can be used to manage problems related to the movement of solutes in rivers and aquifers. The analysis of solute transport is used to safeguard the quality of surface and ground water and to help prevent eutrophication. Solute flow through the soil can be dynamically linked to overland flow for hydrological and agricultural applications. Advances in modelling also cast new light on sediment transport in rivers, exploring the complex dynamics of river bed erosion and deposition and assist in thee analysis of river-reservoir systems. All these issues are discussed in Numerical Modelling of Hydrodynamics for Water Resources, which will be useful to civil engineers, applied mathematicians, hydrologists, and physicists.

Download or read book Numerical Modeling and Hydrologic Analysis of Floodplain Hydrogeology Bank Storage Interactions and Underflow in the Colorado River Alluvial Aquifer written by Barry J. Hibbs and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive hydrogeological investigation was conducted within the Colorado River alluvial aquifer of south-central Texas. The study characterized bank storage interactions caused by irrigation and flood releases from the Highland Lake Reservoirs above Austin, and evaluated the underflow criterion for managing water resources in the Colorado River Basin. The hydrodynamics of the bank storage effect were studied in an integrated tracer and modeling investigation. Variations in dissolved solids between Colorado River water and ground-water created ideal conditions for analysis of stream/aquifer interaction during natural and artificial floodwaves. Two sites were instrumented with observation well and stream-stage recorders. At each site, head, temperature, and chemical data were collected during low-flow, mid-flow, and peak-flow conditions. Significant variations in stream stage and reversals of hydraulic gradient in the adjoining alluvial aquifer were created by releases of water from upstream reservoirs both in response to storm events and for irrigation by downstream users. Aquifer head responded relatively rapidly to changing stream stage during controlled reservoir releases, but tracer (both solute and heat) breakthrough curves were generally not observed even for observation wells very close to the Colorado River. The water table response lagged behind the average head response in the observation wells. These results are postulated to occur as a result of elastic head response in the shallow, unconfined aquifer to rapid changes in stream stage, analogous to the delayed yield effect in an unconfined aquifer during the early stages of pumping. The coupled-process numerical model HST3D was used to develop confined and unconfined aquifer models to simulate the stream/aquifer response. Although the aquifer is clearly recognizable as an unconfined aquifer, the confined aquifer model gave a superior simulation. Both modeling and field data support the hypothesis of elastic head recovery response in the unconfined aquifer. The underflow criterion was evaluated as a legal provision to prevent stream depletion of the Colorado River by high capacity alluvial wells. Study results indicate that the Colorado River alluvial aquifer is not an underflow-dominated system. Even so, site-specific investigations showed that temporally varying underflow zones sometimes exist very close to the river. In more than 90% of the floodplain, data are not available to identify these zones. Beyond the underflow zones, the hydraulic connection between the Colorado River and the alluvial aquifer may extend thousands of feet into the floodplain. Therefore, the potential for stream depletion by wells distant from the underflow zone(s) is great. Study results suggest that the underflow criterion will not be effective as a provision to prevent stream depletion of the Colorado River as the floodplain undergoes agricultural and urban development.

Download or read book Numerical Groundwater Modelling written by William C. Walton and published by CRC Press. This book was released on 1989-01-01 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This valuable new book, with 2 programs on diskettes, will help practitioners in solving groundwater flow and contamination problems by integrating simulation techniques. The reader is expected to have knowledge of hydrogeology, and have access to books on groundwater hydrogeology. Two microcomputer programs, in compiled FORTRAN 77 with source codes for simulating quasi-three-dimensional groundwater flow and contaminant migration, are presented in this book. The numerical and analytical techniques incorporated in these programs are described in detail. Data entry has been simplified so that the user can run the programs without worrying about FORTRAN input file structures and editors. The basic requirements are a monitor, dot-matrix printer, and an IBM-PC or compatible computer running DOS Version 2.1 or compatible. Programs require a full 640K RAM (minus that used by DOS) for their operation.

Download or read book Simulated Pond aquifer Interactions Under Natural and Stressed Conditions Near Snake Pond Cape Cod Massachusetts written by Donald A. Walter and published by . This book was released on 2002 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: ...Discusses the pond-bottom hydraulic conductivity of the Snake Pond, a body of water next to the Massachusetts Military Reservation on Cape Cod; data from this study should prove helpful in dealing with nearby pollution...

Download or read book Groundwater surface Water Interaction written by Corinna Abesser and published by . This book was released on 2008 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected papers from a symposium on A new Focus on Integrated Analysis of Groundwater-Surface Water Systems, held during the International Union of Geodesy and Geophysics XXIV General Assembly in Perugia, Italy, 11-13 July 2007.

Download or read book Modelling Groundwater Systems Understanding and Improving Groundwater Quantity and Quality Management written by Girma Yimer Ebrahim and published by CRC Press. This book was released on 2014-05-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Groundwater is increasingly subjected to excessive over-exploitation and contamination in many parts of the world. It faces the challenge of balancing its multiple functions in a sustainable manner. This thesis explores several specific problems related to contaminant migration, groundwater-surface water interactions and managed aquifer recharge, using a variety of simulation methods and combined simulation-optimization modelling approaches. The validity of these approaches for evaluating groundwater quantity and quality management options is explored. Case studies were performed on field applications in Belgium, Germany and Oman. The results of these studies demonstrate that better insights and improved groundwater resource management can be achieved through a combination of different simulation and optimization methods that take into account data availability and specific site conditions.

Download or read book Ground and Surface water Interaction Between the Kansas River and Associated Alluvial Aquifer Northeastern Kansas written by R. J. Wolf and published by . This book was released on 1993 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sensitivity analysis of time step in modeling river and aquifer interaction written by Shiva Niazi and published by . This book was released on 2000 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aquifer Test Modeling written by William C. Walton and published by CRC Press. This book was released on 2006-11-15 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recognition of the trend toward using numerical methdos for analyzing aquifer test data, Aquifer Test Modeling delineates the application of numerical Laplace inversion analytical equations and numerical models and demonstrates the use of public domain software. Written by a leading expert with over fifty years of experience, this highly practical text provides a thorough grounding in the terms and methods employed in aquifer test modeling, while also establishing a protocol for organizing and simplifying conceptual model definition and data analysis. Using graphs, tables, and sample datasets to enhance understanding, the author delineates the five major steps involved in the aquifer test modeling process. He discusses the importance of the conceptual model definition as a framework for organizing, simplifying, and idealizing information. The chapters cover the selection of appropriate aquifer test mathematical model equations compatible with previously defined conceptual models and highlight the importance of reviewing the mathematical assumption and the adjustment of data for any departures. They also explain format selection, technique selection, well function or drawdown calculation, and calibration. The book provides five sample data sets to assist the reader in becoming familiar with WTAQ and MODFLOW aquifer test modeling input and output data file contents with confined nonleaky and unconfined aquifer conditions. It includes conceptual models consisting of abbreviated descriptions of aquifer test facilities, aquifer test data, and aquifer parameter values together with selected sample file sets. These are just a few of the features that make the book a valuable tool for estimating the supply and contamination characteristics of aquifers.

Download or read book Water resources Investigations Report written by and published by . This book was released on 1999 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: