Use of three generations of oil spill models during the Gulf War oil spills

During the January-May 1991 Gulf War, an estimated 6 million bbl of oil was spilled into the Arabian Gulf, mostly around Mina Al-Ahmadi in southern Kuwait. Three models were used to analyze the fate and transport of the spills originating at Al-Ahmadi. The first generation model, GULFSLIK I, was developed in the late 1970s and predicts the movements of a spill by considering that the center of the slick advects with a velocity equal to 3% of the wind speed. This model is best for the initial forecasting of oil spill movement. The second generation GULFSLIK II Model predicts the trajectory of spills at 24 h intervals, requiring as input the average daily wind velocity. Surface currents are obtained for the model from a reliable 3-dimensional hydrodynamic model of the Gulf coupled with an appropriate interpolation scheme. Comparisons between predicted spill trajectories and actual sightings show GULFSLIK II to be reasonably accurate. The third generation model, called OILPOL, consists of a set of algorithms describing the processes of advection, turbulent diffusion, surface spreading, vertical mechanical dispersion, emulsification, and evaporation. After 80 days, results show under 8% of the initial oil volume remains on the sea surface while 15% is suspended in the water column or sedimented on the sea bed. Comparisons of simulation results and actual sightings show excellent agreement. 4 refs., 7 figs., 2 tabs