Regional contingency planning using the OSCAR oil spill contingency and response model

Oil spill contingency planning requires the quantitative comparison of alternative response options so that the most appropriate, effective and/or cost-effective option can be recommended. A model system for Oil Spill Contingency and Response (OSCAR) has been used to evaluate first line oil spill response strategies for different fields in the Norwegian sector of the North Sea. The system consists of a three-dimensional numerical model of the physical and chemical behavior and fate of spilled oil, and an oil spill response simulation of various currently available mechanical recovery and dispersant application systems. By providing a quantitative and more objective assessment of response performance, the response can be dimensioned based on physical or biological criteria set for the region in question. The cost, effectiveness (as defined on the basis of various criteria) and environmental benefit of various options can be compared. The paper demonstrates how weathering studies combined with modelling of probable spill scenarios can be used to develop relevant, site-specific contingency plans. The effect of oil type, spill size and release conditions on response performance is clearly demonstrated.