Monte Carlo Simulation of Oil Slick Movements

A random walk analogy and a time series model are described to simulate, by the Monte Carlo method, the movement of an instantaneous oil slick under the influence of deterministic water currents and random wind effects. The technique is based on model sampling or repeated trials. Therefore, the slick motion is imitated by the movement of a large number of particles, each of which undergoes a sequence of deterministic steps due to a prescribed water current field and a different sequence of random steps due to a random wind field. This enables one to estimate the probability distributions of the position of the oil slick centroid and nearshore pollution after a spill occurs. An illustrative example based on some empirical formulas and actual field data from Delaware Bay is given. Of the two models on which the simulation is based, it is judged that the time series simulation model represents a more realistic and conservative approach.