FIG. 6. Breakthrough curves calculated using the Dual-Permeability Model for a 10-cm-long soil column and the following parameters: q_m = 3 cm d^–1, q_f = 30 cm d^–1, = _m = _f = 0.5, w = 0.1, _m = _f = 1 cm, K_dm = K_df = 1 cm³ g^–1, _b = 1.5 g cm^–3, and _dp = 0, 0.1, and 0.5 d^–1. Matrix, fracture, and total breakthrough curves are represented by thin, medium, and thick lines, respectively.