Coefficients of spatial variation (CSVs) amongst chamber replicates (2 x 3 m grid) during emission events were 28 to 195 %, indicating that spatial variation of N2O occurs at a very small spatial scale. CSVs of N2O modeled from the grid cells in which chambers were located were 11 to 49% when uniform soil properties were assumed across the field. This variation was attributed in the model only to spatial variation of WFPS, due to different flow accumulation within the field caused by topographically-driven water movement (~1.8m over 600m). Consequently, EF for 112 kg N ha-1 was larger in an area of the field with lower topography (1.27%) compared to one with higher (0.73%). These results show the importance of the use of 3-dimensional models such as ecosys at an hourly time-step with input from DEMs, to fully capture large spatial and temporal variability of N2O at different spatial scales even in seemingly flat (0.2% slope) landscapes.