3.1 Trajectory models are used to predict the future movement and fate of oil (forecast mode) in contingency planning, in exercises and during real spill events. This information is used for planning purposes to position equipment and response personnel in order to optimize a spill response. Oil-spill trajectory models are used in the development of scenarios for training and exercises. The use of models allows the scenario designer to develop incidents and situations in a realistic manner.

3.2 Oil-spill trajectory models can be used in a statistical manner (stochastic mode) to identify the areas that may be impacted by oil spills.

3.3 In those cases where the degree of risk at various locations from an unknown source is needed, trajectory models can be used in an inverse mode to identify the sources of the pollution (hindcast mode).

3.4 Models can also be used to examine habitats, shorelines, or areas to predict if they would be hit with oil from a given source (receptor mode).

1.1 This practice describes the features and processes that should be included in an oil-spill trajectory and fate model.

1.2 This practice applies only to oil-spill models and does not consider the broader need for models in other fields. This practice considers only computer-based models, and not physical modeling of oil-spill processes.

1.3 This practice is applicable to all types of oil in oceans, lakes, and rivers under a variety of environmental and geographical conditions.

1.4 This practice applies to two-dimensional models. There are three-dimensional models in the marketplace.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.