Hydraulic-Head BC

Units [L]

A hydraulic-head boundary condition applies a predefined hydraulic head to a node. Instead of calculating hydraulic head as a simulation result, at these nodes the head is given by the boundary condition value. This can lead to an inflow into the model when neighboring nodes have a lower potential, or to an outflow from the model when there is a gradient from the neighboring nodes towards the boundary condition.

Head boundary conditions are applied in cases where the hydraulic potential is known in advance. This can be the case for example for surface water bodies with a perfect connection to groundwater (surface water level equals groundwater level), for pump sumps where a constant level is kept for dewatering purposes, or for seepage faces (in combination with a constraint condition).