Deep percolation, saturated lower boundary

A vertical water flow, i.e. deep percolation, from the lowest compartment (see switch LBoundSaturated) may optionally be calculated by a unit gradient i.e. by gravitational forces (see eq.(2.37))only, it may be assumed equal to zero or, if the lower boundary is saturated, it may be based on the seepage equation and calculated as:

                                                (2.38)

where k_sat is the conductivity of lowest layer, z_sat is the simulated depth of the ground water table, z_p2 is the depth of a drain level with a parallel geometry at a spacing distance of d_p2. See viewing function Bottom Boundary Seepage Equation.