Thomas E. Reilly Gordon D. Bennett O. Lehn Franke 1987 Accurate definition of boundary and initial conditions is an essential part of conceptualizing and modeling ground-water flow systems. This report describes the properties of the seven most common boundary conditions encountered in ground-water systems and discusses major aspects of their application. It also discusses the significance and specification of initial conditions and evaluates some common errors in applying this concept to ground-water-system models. An appendix is included that discusses what the solution of a differential equation represents and how the solution relates to the boundary conditions defining the specific problem. This report considers only boundary conditions that apply to saturated ground-water systems. application/pdf 10.3133/twri03B5 en U.S. G.P.O., Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems - An introduction reports