Introduction. Basic Concepts: Darcy's Law. Continuity of Flow. Laplace's Equation. Dupuit-Forchheimer Flow: Elementary Solutions. Areal Recharge. Multiple Aquifers. Heterogeneous Aquifers. Approximate Vertical Flow. Transient Flow. Complex Potential Theory. Three-Dimensional Flow: Basic Equations. Three-Dimensional Confined Flow. Combined Two- and Three-Dimensional Flow. Analytic Element Modeling: The Analytic Element Method. The Program GFLOW1. Basic Modeling Concepts. Field Applications: Wellhead Protection. Fate of Contaminants. Drawdown Predictions. Bibliography. Subject Index.