Modelling of Oil-Sediment Aggregates Trajectories Along Gulf of Khambhat, West Coast of India

Abstract

Oil spill accidents on the marine waters impose great threat to the marine organism, humans and economic. Continuous efforts have been made to achieve effective mitigation measures to avoid the damage to the marine environment. Countermeasures, to combat the spilled oil, are to be taken, by the response action team, with thorough knowledge on the spilled oil conditions, characteristics and projected trajectory of oil sleek movements on the water surface. In the present study, experimental investigations are carried out to understand the interaction between the oil droplets and suspended sediments to form aggregates. Further, the laboratory results on the formed aggregates (OSAs) sizes are used as an input to the numerical model investigation. To demonstrate the use of numerical model to estimate the trajectories of a hypothetical oil spill incident, a 2D oil spill trajectory model is developed for Gulf of Khambhat, West Coast of India. A finite element method-based numerical scheme, TELEMAC-2D, is used for this study, which also capable of estimating the ambient hydrodynamics that drive the spilled oil to spread spatially. In addition to the estimate of spilled oil trajectory, oil-sediment aggregates trajectories are also investigated using the numerical model. From the numerical model results, it is evident that the area influenced by the OSAs is significantly small compared the ambient oil spill conditions, which may be thought of an alternate option for combating any future oil spill incidents.