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system, an aquifer, or a system of aquifers, means making such decisions as to the total quantity of water to be withdrawn annually, the location of wells for pumping and for artificial recharge and their rates, and control conditions at aquifer boundaries.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.
Inhaltsverzeichnis
1. Introduction. - 1. 1. Groundwater and Aquifers. - 1. 2. Management of Groundwater. - 1. 3. Groundwater Modeling. - 1. 4. Continuum Approach to Porous Media. - 1. 5. Horizontal Two-Dimensional Modeling of Aquifers. - 1. 6. Objectives and Scope. - 2. Groundwater Motion. - 2. 1. Darcy s Law and its Extensions. - 2. 2. Aquifer Transmissivity. - 2. 3. Dupuit Assumption. - 3. Modeling Three-Dimensional Flow. - 3. 1. Effective Stress in Porous Media. - 3. 2. Mass Storage. - 3. 3. Fundamental Mass Balance Equation. - 3. 4. Initial and Boundary Conditions. - 3. 5. Complete Statement of Mathematical Flow Model. - 3. 6. Modeling Soil Displacement. - 4. Modeling Two-Dimensional Flow in Aquifers. - 4. 1. Aquifer Storativity. - 4. 2. Fundamental Continuity Equations. - 4. 3. Initial and Boundary Conditions. - 4. 4. Complete Statement of Aquifer Flow Model. - 4. 5. Regional Model for Land Subsidence. - 4. 6. Streamlines and Stream Function. - 5. Modeling Flow in the Unsaturated Zone. - 5. 1. Capillarity and Retention Curves. - 5. 2. Motion Equations. - 5. 3. Balance Equations. - 5. 4. Initial and Boundary Conditions. - 5. 5. Complete Statement of Unsaturated Flow Model. - 6. Modeling Groundwater Pollution. - 6. 1. Hydrodynamic Dispersion. - 6. 2. Advective, Dispersive, and Diffusive Fluxes. - 6. 3. Balance Equation for a Pollutant. - 6. 4. Initial and Boundary Conditions. - 6. 5. Complete Statement of Pollution Model. - 6. 6. Pollution Transport by Advection Only. - 6. 7. Macrodispersion. - 7. Modeling Seawater Intrusion. - 7. 1. The Interface in a Coastal Aquifer. - 7. 2. Modeling Seawater Intrusion in a Vertical Plane. - 7. 3. Modeling Regional Seawater Intrusion. - 8. Introduction to Numerical Methods. - 8. 1. Analytical versus Numerical Solutions. - 8. 2. Survey of Numerical Methods. - 8. 3. Computer Programming. - 9. The Finite Difference Method. - 9. 1. SteadyFlow. - 9. 2. Unsteady Flow. - 9. 3. Accuracy and Stability. - 9. 4. Generalizations. - 10. The Finite Element Method. - 10. 1. Steady Flow. - 10. 2. Steady Flow in a Confined Aquifer. - 10. 3. Steady Flow with Infiltration and Leakage. - 10. 4. Steady Flow through a Dam. - 10. 5. Unsteady Flow in an Aquifer. - 10. 6. Generalizations. - 11. Transport by Advection. - 11. 1. Basic Equations. - 11. 2. Semi-Analytic Solution. - 11. 3. System of Wells in an Infinite Field. - 11. 4. System of Wells in an Infinite Strip. - 11. 5. Numerical Solution in Terms of the Piezometric Head. - 11. 6. Numerical Solution in Terms of the Stream Function. - 11. 7. Tracing Particles Along a Stream Line. - 12. Transport by Advection and Dispersion. - 12. 1. Dispersion in One-Dimensional Flow. - 12. 2. Numerical Dispersion. - 12. 3. A Finite Element Model for Two-Dimensional Problems. - 12. 4. Random Walk Model. - 13. Numerical Modeling of Seawater Intrusion. - 13. 1. Model for Flow in a Vertical Plane. - 13. 2. Basic Equations for a Regional Model of Seawater Intrusion. - 13. 3. Finite Element Model for Regional Interface Problems. - Appendix. Solution of Linear Equations. - References. - Problems. - Index of Subjects.
