Fig. 5. Sensitivity analysis of model input parameters. The reference simulation was done using the following parameters: C(z = 0–30 cm) = 1 µg L^–1, C(z > 30 cm) = 0 µg L^–1, k_P = 4 Pa, e = 700 Pa, Q_HM = 10, Q_Y = 0.5, = 1, and = 8 m^–1.