Fig. 5. Scatterplot comparison of predicted and measured soil-gas diffusivities (D_p/D₀) for lysimeter soils (Rønhave, Foulum, and Jyndevad) and field soils (Gjorslev and Mammen). All measured data are given. Model predictions are: (a, b) the Millington and Quirk (1961) model (MQ) and (c, d) the three-porosity model (TPM). Calculated RMSE values using D_p/D₀ data and log-transformed D_p/D₀ data (values in brackets), Eq. [1], are given. Note different axes and log scale.