Although surface runoff plays an important role in contaminant transport, it remains poorly quantified. Because it is difficult to measure directly and computationally demanding to model at scales larger than the field-scale, there is a need for efficient upscaling methods. This research will explore the applicability of both high- and low-end models to calculate surface runoff at field scale and from there develop an effective upscaling procedure, enabling more accurate estimates of surface runoff at the regional scale. Because it is one of the most important controlling factors, the focus of upscaling efforts will lie on parameterizing microtopographic variability.