Computational experiments are carried out with the rainfall field model described in Part 1 of this paper and a physically based distributed modelling system, the Systeme Hydrologique Europeen (SHE), to explore the interaction between spatial variability in rainfall and other factors controlling catchment response; both models have been calibrated for the small upland Wye catchment (area 10.55 km 2 ). Simulated rainfall fields are used to provide fully distributed rainfall inputs to the SHE; the corresponding true catchment responses are then compared with those derived from incomplete sampling of the rainfall fields. The differences in simulated peak discharges and runoff volumes are assessed as a function of antecedent catchment conditions, network density and the level of spatial correlation in the rainfall input. A piecewise linear transfer function model with an averaged rainfall input is used to approximate SHE responses to fully distributed rainfall inputs, to provide insight into simple lumped model performance.