ABSTRACT
Groundwater modeling is an area of importance to practitioners as well as researchers. However, the term can mean dierent things to dierent people. Our denition of groundwater is broad in the sense that we consider systems that may contain multiple uid phases and may involve species composition as long as water is an important part of the system. For example, this denition excludes important porous medium systems such as petroleum reservoirs. Modeling can refer to the formulation of a mathematical model, which is an active area of research (e.g., Gray and Miller, 2014), derivation of a solution to a given model formulation, or application of an available simulator to a specic physical system of interest.
