Fig. 4. The modeled pesticide concentration in soil water down the soil profile on 31 Aug. 1997 (129 d after treatments [DAT]) and 1998 (134 DAT). (a) seepage rate = 0.23 cm d^-1(observed) and nodal point (NP) = 81 in 1997, (b) seepage rate = 0.23 cm d^-1 (observed) and NP = 81 in 1998, (c) seepage rate = 0.23 cm d^-1 (observed) and NP = 31 in 1998, and (d) seepage rate = 0.90 cm d^-1 (estimated) and NP = 31 in 1998.