Modeling Groundwater Flow and Pollution


Book Description

Groundwater constitutes an important component of many water resource systems, supplying water for domestic use, for industry, and for agriculture. Management of a groundwater system, an aquifer, or a system of aquifers, means making such decisions as to the total quantity of water to be withdrawn annually, the location of wells for pumping and for artificial recharge and their rates, and control conditions at aquifer boundaries. Not less important are decisions related to groundwater qUality. In fact, the quantity and quality problems cannot be separated. In many parts of the world, with the increased withdrawal of ground water, often beyond permissible limits, the quality of groundwater has been continuously deteriorating, causing much concern to both suppliers and users. In recent years, in addition to general groundwater quality aspects, public attention has been focused on groundwater contamination by hazardous industrial wastes, by leachate from landfills, by oil spills, and by agricultural activities such as the use of fertilizers, pesticides, and herbicides, and by radioactive waste in repositories located in deep geological formations, to mention some of the most acute contamination sources. In all these cases, management means making decisions to achieve goals without violating specified constraints. In order to enable the planner, or the decision maker, to compare alternative modes of action and to ensure that the constraints are not violated, a tool is needed that will provide information about the response of the system (the aquifer) to various alternatives.




3D-Groundwater Modeling with PMWIN


Book Description

This book and CD-ROM offer a complete simulation system for modeling groundwater flow and transport processes. The companion full-version software (PMWIN) comes with a professional graphical user-interface, supported models and programs and several other useful modeling tools. Tools include a Presentation Tool, a Result Extractor, a Field Interpolator, a Field Generator, a Water Budget Calculator and a Graphic Viewer. Book and CD-ROM are targeted at novice and experienced groundwater modelers.




Mathematical Modeling of Groundwater Pollution


Book Description

Groundwater is one of the most important resources in the world. In many areas, water supplies for industrial, domestic, and agricultural uses are de pendent on groundwater. As an "open" system, groundwater may exchange mass and energy with its neighboring systems (soil, air, and surface water) through adsorption, ion-exchange, infiltration, evaporation, inflow, outflow, and other exchange forms. Consequently, both the quantity and quality of groundwater may vary with environmental changes and human activities. Due to population growth, and industrial and agricultural development, more and more groundwater is extracted, especially in arid areas. If the groundwater management problem is not seriously considered, over extraction may lead to groundwater mining, salt water intrusion, and land subsidence. In fact, the quality of groundwater is gradually deteriorating throughout the world. The problem of groundwater pollution has appeared, not only in developed countries, but also in developing countries. Ground water pollution is a serious environmental problem that may damage human health, destroy the ecosystem, and cause water shortage.




Ground Water Models


Book Description

The discovery of toxic pollution at Love Canal brought ground water contamination to the forefront of public attention. Since then, ground water science and modeling have become increasingly important in evaluating contamination, setting regulations, and resolving liability issues in court. A clearly written explanation of ground water processes and modeling, Ground Water Models focuses on the practical aspects of model application. It: examines the role of models in regulation, litigation, and policy development; explains ground water processes and describes specific applications for models; presents emerging technologies; and offers specific recommendations for better use of ground water science in policy formation.




Groundwater Contamination: Use of Models in Decision-Making


Book Description

The protection of groundwater resources has emerged in recent years as a high priority topic on the agenda of many countries. In responding to the growing concern over deteriorating groundwater quality, many countries are developing a comprehensive regulatory framework for the management of subsurface water resources with management referring to both quantity and quality aspects. Within this framework, groundwater models are rapidly coming to playa central role in the development of protection and rehabilitation strategies. These models provide forecasts of the future state of the groundwater aquifer systems and/or the unsaturated zone in response to proposed management initiatives. For example, models will predict the effects of implementing a proposed management scheme on water levels and on the transport and fate of pollutants. The models are now used in the formulation of policies and regulations, the issuing of permits, design of monitoring and data collection systems, and the development of enforcement actions. The growth in the use of these sophisticated tools has led to many unforeseen problems in groundwater management. Lingering issues include reliability of codes, quality assurance in model development and applications, efficient utiliza tion of human and material resources, technology transfer and training. Some issues have legal ramifications, as in cases where the applications of models have been contested in courts.




Modeling Groundwater Flow and Contaminant Transport


Book Description

In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use, and contamination. To face the challenge, good planning and management practices are needed. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface. The purpose of this book is to construct conceptual and mathematical models that can provide the information required for making decisions associated with the management of groundwater resources, and the remediation of contaminated aquifers. The basic approach of this book is to accurately describe the underlying physics of groundwater flow and solute transport in heterogeneous porous media, starting at the microscopic level, and to rigorously derive their mathematical representation at the macroscopic levels. The well-posed, macroscopic mathematical models are formulated for saturated, single phase flow, as well as for unsaturated and multiphase flow, and for the transport of single and multiple chemical species. Numerical models are presented and computer codes are reviewed, as tools for solving the models. The problem of seawater intrusion into coastal aquifers is examined and modeled. The issues of uncertainty in model input data and output are addressed. The book concludes with a chapter on the management of groundwater resources. Although one of the main objectives of this book is to construct mathematical models, the amount of mathematics required is kept minimal.




Groundwater Modeling


Book Description







Numerical Models in Groundwater Pollution


Book Description

Mathematical models are powerful tools used in the prediction of pollutant movement. This book discusses the Finite Element Method (FEM) and Boundary Element Method (BEM), and takes a look at the advantages of these methods in groundwater hydrology. The combination of the BEM and the random-walk particle tracking method is also presented. The book includes computer programs, source code, and examples developed on the basis of the theoretical backgrounds of these methods. These Visual C++ programs are compatible with the Windows platform.




Groundwater Hydrology


Book Description

A thorough, up-to-date guide to groundwater science and technology Our understanding of the occurrence and movement of water under the Earth's surface is constantly advancing, with new models, improved drilling equipment, new research, and refined techniques for managing this vital resource. Responding to these tremendous changes, David Todd and new coauthor Larry Mays equip readers with a thorough and up-to-date grounding in the science and technology of groundwater hydrology. Groundwater Hydrology, Third Edition offers a unified presentation of the field, treating fundamental principles, methods, and problems as a whole. With this new edition, you'll be able to stay current with recent developments in groundwater hydrology, learn modern modeling methods, and apply what you've learned to realistic situations. Highlights of the Third Edition * New example problems and case studies, as well as problem sets at the end of each chapter. * A special focus on modern groundwater modeling methods, including a new chapter on modeling (Chapter 9), which describes the U. S. Geological Survey MODFLOW model. * Over 300 new figures and photos. * Both SI and U.S. customary units in the example problems. * Expanded coverage of groundwater contamination by chemicals. * New references at the end of each chapter, which provide sources for research and graduate study. Student and instructor resources for this text are available on the book's website at www.wiley.com/college/todd.