where ρ is the fluid density,
g denotes the acceleration of gravity, and
D is the elevation. When defined as vertical elevation, the horizontal gradients in
D equal zero and vertical gradients in
D equal one. Choose to specify pressure, hydraulic head, or pressure head on the boundaries of a model, either directly or as part of the pervious layer boundary condition. Also use pressure, hydraulic head, and pressure head during analysis and postprocessing.
