(S_r)

Residual saturation defined ad hoc by Brooks & Corey, 1964 as given in [16]

[1]

(t)

Time elapsed

[T]

(t_f)

Time at the final stage of percolation

[T]

(T), (T_i)

Temperature, (_i) denotes the initial phase

[Θ]

(t_i)

Time at the initial stage of percolation

[T]

(t_p)

Time at the beginning of the ponding stage of percolation

[T]

(z)

Percolation depth (vertical)/wetting front/heat transfer length (vertical)/membranes penetration depth

[L]

(V)

Water volume

[L³]

(V_s)

Volume of the bulk soil or massive soil (control volume)

[L³]]

(v_z)

Vertical percolation velocity defined as the percolation that occurs in the vertical direction

[L∙T⁻¹]

(z)

Vertical distance/penetration depth/wetting depth/penetration depth at saturation state

[L]