Fig. 1 Sensitivity coefficients, µ and µ_Ks to 1% changes in and q/K_s. (a) and (b): for pressure head, (c) and (d): for water storage, and (e) and (f): for tracer travel time. Other parameters included: horizontal distance perpendicular to the source x = 0, L = 0.4 m, _sk = 0.4, _rk = 0.05, _k = 12 m^-1, K_sk = 2.8 x 10^-5 m s^-1, and q = 1 x 10^-6 m² s^-1. Subscript k stands for the true value of the corresponding parameter