**2.2 Oil spill modelling**

The oil model is a multi-component model, i.e. the total oil mass is distributed among different hydrocarbon components, typically defined by their density. The masses and the properties of each particle may change over time due to weathering. Each oil component has its own weathering process. The fate of the spilled oil is typically divided into different processes:


*Combining Predicted Seabird Movements and Oil Drift Using Lagrangian Agent-Based Model… DOI: http://dx.doi.org/10.5772/intechopen.106956*

**Figure 2.** *Processes acting on spilled oil, (modified after [9]).*

• Weathering (**Figure 2**) processes causing physical and bio-chemical changes of the oil by evaporation, emulsification, biodegradation, dispersion, dissolution, oxidation, and sedimentation and beaching. Spreading, evaporation, dispersion, and dissolution can be defined as short-term weathering processes, whereas emulsification, biodegradation, and photochemical oxidation are recognised as long-term weathering processes (**Figure 2**).
