During the limited variant conditions, the impacted area decreased in size. The change of the cumulative probabilities seems to be the opposite of transient changes, and they increase as the distance increases. With respect to the annual character, the north wind is the most frequent. The spill events took place in July when the south wind became prevalent. Therefore, the region that suffered first from oil contamination appears in the south in E01, whereas the oil slick is prone to moving northward in E02.
Validation of the model in terms of the polluted area is conducted by comparing both the statistical results of the numerical model to that recorded by aerial photography (Fig. 12). The root-mean-squared-error (RMSE) of E02 is 15.6 km2, which is less than the 22.7 km2 of E01. The slick swept area is closer than 1% to the actual area using the probability from E02, indicating that the probabilistic model with analogous partial conditions to the actual event can effectively improve its accuracy.