Impact of oil−sediment interaction on transport of underwater spilled oil in the Bohai Sea

Abstract

Based on a validated underwater oil spill model and validated ocean hydrodynamic background, the influence of oil−sediment interaction on the transport of underwater spilled oil is investigated through numerical experiments. Numerical result shows that interaction between oil and suspended sediment can form oil−sediment aggregates (OSAs), which can significantly decrease the amount of surface oil and increase the amount of underwater oil and its sweeping volume under certain conditions. Sensitivity of the model output (in terms of oil in OSAs, underwater oil amount, surface oil amount, and sweeping volume) to input factors (including oil spill volume, sediment diameter, and sediment concentration) is further investigated quantitatively through numerical experiments, which shows that increasing oil spill volume and sediment concentration and reducing sediment diameter can promote oil−sediment interaction. Among the three input factors, oil spill volume is the most sensitive factor, followed by sediment concentration and sediment diameter. This study is expected to provide useful information for spilled oil monitoring, contingency planning, and environmental damage assessment.