Numerical modelling of oil spills in coastal zones. A case study

Proceedings of the XVIIIth Telemac & Mascaret User Club 2011, 19-21 October 2011, EDF R&D, Chatou, 2011

The European Water Framework Directive together with the requirement to monitor water resources for drinking as well as leisure and industrial purposes, have substantially increased the demand for water-quality evaluation and monitoring systems. The Migr'Hycar research project was initiated to provide decisional tools, and to fulfil operational needs, for risks connected to oil spill drifts in continental waters (rivers, lakes, estuaries). Within the framework of the Migr'Hycar project, a new numerical oil spill model has been developed by combining Lagrangian and Eulerian methods. This model enables to simulate the main processes that act on the spilled oil: advection, diffusion, evaporation, dissolution, spreading and volatilization. Though generally considered as a minor process, dissolution is important from the point of view of toxicity. The Lagrangian model describes the transport of an oil spill near the free surface. To model dissolved oil in water, an Eulerian advectiondiffusion model is used. The fraction of dissolved oil is represented by a passive Eulerian scalar. This model is able to follow dissolved hydrocarbons in the water column (PAH: Polycyclic Aromatic Hydrocarbons). The Eulerian model is coupled with the Lagrangian model. In parallel with model development, two types of experiments on the behavior of hydrocarbons have been carried out: • Static chemical laboratory experiments in order to study the kinetic of dissolved petroleum in a beaker. • Dynamic experiments in artificial river facility. After releasing refined commercial products (fuel and heavy oil) into an artificial channel, the aim of these experiments was to study the drift of the oil spill and the dissolution in the water column. Static experiments allow a calibration of evaporation, dissolution and volatilization mass transfer coefficients used in the model. Then, the model is validated with the artificial river experiments. Comparisons of numerical results with measured data are presented in this paper. I.

Oil and Chemical Pollution, 1989

Oil spill trajectory and fates models typically follow a surface s~ck until it contacts a coastline, at which time the simulation ceases. The coastal zone oil spill (COZOIL) model described here is designed to simulate oil spill fates both before and after a coastal contact. Multiple discrete batches of oil (spillets) are used to represent the surface slick. Spillets are circular while offshore but become elliptical upon contact with the shoreline. Onshoreoffshore foreshortening is governed by a balance between wind stress and gravity spreading forces, and results in alongshore spreading of the spillet. Evaporated hydrocarbons are accumulated from all sources during the simulation, with no spatial representation. Entrained oil offshore is represented by discrete particles which may be advected by the local currents. Inside the surf zone, entrained oil takes on a continuous representation, discretized within individual alongshore grid cells. Transport in the sulf zone is governed by a classical radiation stress formulation. Incorporation of water into surface oil (emulsification) is simulated offshore. De-emulsification (de-watering) is allowed to occur for oil which is on the foreshore or backshore. Oil coming ashore may be deposited on the foreshore or the backshore, or carried into coastal indentations

Marine Pollution Bulletin, 2017

A review of the state of the art in oil spill modeling, focused on the period from 2000 to present is provided. The review begins with an overview of the current structure of spill models and some lessons learned from model development and application and then provides guiding principles that govern the development of the current generation of spill models. A review of the basic structure of spill models, and new developments in specific transport and fate processes; including surface and subsurface transport, spreading, evaporation, dissolution, entrainment and oil droplet size distributions, emulsification, degradation, and sediment oil interaction are presented. The paper concludes with thoughts on future directions in the field with a primary focus on advancements in handling interactions between Lagrangian elements.

International Oil Spill Conference Proceedings, 1995

The status and possible research directions of oil spill modeling are presented here. The physical and chemical processes that take place in oil spills are explained as is their role in the design of an ideal oil spill model. An ideal oil spill model for forecasting must support rapid response, contingency planning, and training. Accurate, full-dimension, real-time prediction of hydrodynamic calculations and oil movements require intensive computations and computing power. Presently the most promising computational platform appears to be a vector supercomputer that has been given essential geographical, bathymetric, and tidal data before the spill. Parallel processing machines could be used in the same way; but present codes, written for sequential machines, must be changed substantially to take advantage of the parallel architecture. Super minicomputer technology is advancing rapidly and should soon be able to run the numerically intensive hydrodynamic codes, bringing the advantage...

Spill Science & Technology Bulletin, 1995

A numerical model for the simulation of tbe physicocbemical weathering processes of an oil spill at sea is presented based on state-of-the-art models. The model includes the most significant processes: spreading, evaporation, dispersion into the water column, emulsification and the change in viscosity and density. These processes depend on each other and are allowed to vary simultaneously since processes are described by a set of differential equations, solved by a fourth-order Rung+Kutta method. Numerical examples are given, in order to test the results obtained, and compared with available experimental data in tbe literature. The model predicts well the variation of water incorporation, density and viscosity but seems to overestimate the fraction evaporated. However more experimental data are needed to calibrate and validate the model since differences in the composition of the simulated oil and the samples from which experimental data are taken may occur in evaporation studies. The model is suitable to join other modules for the prediction of the spill trajectory by advection due to winds and currents and sub-sea transport.

Journal of Applied Mathematics, 2012

The spreading of oil in an open ocean may cause serious damage to a marine environmental system. Thus, an accurate prediction of oil spill is very important to minimize coastal damage due to unexpected oil spill accident. The movement of oil may be represented with a numerical model that solves an advection-diffusion-reaction equation with a proper numerical scheme. In this study, the spilled oil dispersion model has been established in consideration of tide and tidal currents simultaneously. The velocity components in the advection-diffusion-reaction equation are obtained from the shallow-water equations. The accuracy of the model is verified by applying it to a simple but significant problem. The results produced by the model agree with corresponding analytical solutions and field-observed data. The model is then applied to predict the spreading of an oil spill in a real coastal environment.

1970

In this paper we will locate our present research results for efforts in Brazil in the realm of oil spill modelling and simulation. In the beginning of the nineties, a project was presented in our University for optimizing resources of clean-up activities following an oil spill. In this global project the mathematical models for numerical simulation should include several phenomena not previously considered in those models then in use by government agencies. The Biomathematics Research Group, of the Applied Mathematics Department then began to work in this direction, using successive variations of some classical models. Besides the theoretical layout, this paper presents some case studies for a specific coastal region in southern Brazil.

Archives of Environmental Protection, 2016

New York Bay is one of the most important transition regions of ships trading to east America. The region plays an important role in the commerce of the New York metropolitan area. The area is surrounded with the coasts that have various levels of environmental sensitivity. The area accommodates high diversity of native ecosystems and species that are rather vulnerable in case of oil spill. Thus getting well informed about the likelihood, or fate, of oil spills around this region is of great importance so that proactive measures can be taken. The purpose of this study is to investigate the oil spill and predict the future accidents likely to be encountered around the Bay of New York. Two trajectory models have been conducted for the study. ADIOS (Automated Data Inquiry for Oil Spills), has been conducted for natural degradation calculations, and, GNOME (General NOAA Operational Modeling Environment), has been conducted for surface spread simulation. The results gained through these efforts are hoped to be useful for many organizations dealing with oil spill response operations and contribute to an effective and effi cient coordination among the relevant institutions.New York Bay is one of the most important transition regions of ships trading to east America. The region plays an important role in the commerce of the New York metropolitan area. The area is surrounded with the coasts that have various levels of environmental sensitivity. The area accommodates high diversity of native ecosystems and species that are rather vulnerable in case of oil spill. Thus getting well informed about the likelihood, or fate, of oil spills around this region is of great importance so that proactive measures can be taken. The purpose of this study is to investigate the oil spill and predict the future accidents likely to be encountered around the Bay of New York. Two trajectory models have been conducted for the study. ADIOS (Automated Data Inquiry for Oil Spills), has been conducted for natural degradation calculations, and, GNOME (General NOAA Operational Modeling Environment), has been conducted for surface spread simulation. The results gained through these efforts are hoped to be useful for many organizations dealing with oil spill response operations and contribute to an effective and effi cient coordination among the relevant institutions.

Spill Science Technology Bulletin, 1999

The state-of-the-art in oil spill modeling is summarized, focusing primarily on the years from 1990 to the present. All models seek to describe the key physical and chemical processes that transport and weather the oil on and in the sea. Current insights into the mechanisms of these processes and the availability of algorithms for describing and predicting process rates are discussed. Advances are noted in the areas of advection, spreading, evaporation, dispersion, emulsi®cation, and interactions with ice and shorelines. Knowledge of the relationship between oil properties, and oil weathering and fate, and the development of models for the evaluation of oil spill response strategies are summarized. Speci®c models are used as examples where appropriate. Future directions in these and other areas are indicated