Study On The Numerical Simulation Of Accidental Oil Spill In The Yueqing Bay

With the development of global oil production and oil transportation, oil spillaccidents are more and more frequent. The oil spill can cause great harm to the marineecological environment and the economic activity of polluted of region. In recent years anumber of oil spill accident s also occurred in China’s sea area.Yueqing Bay is rich in wetland,coastal resources and biological species. Withthe construction projects in Yueqing Bay increasing, the ships sailing in Yueqing Bayincreases.Once the oil spill accident happens, there will be a serious threat toecological environment of Yueqing Bay. In order to limit the oil spill and promoteclean work smoothly, it is needed to get the knowledge of the motion path and theextent of the oil spill. In addition to the monitoring work about the oil spill in the sea,it is also needed to forecast the oil drift trajectory by a oil spill model with currentsand winds data of the oil spilled region.Since the1960s, scientists have paid lots of attention on the research of oil spillpollution problems. A lot of researches have been done and many achievements havebeen obtained but the fate and the transport of the spilled oil is a very complexprocess and is difficult to be described with a single model, therefore there are manytopics left still to be studied. In the previous research some semi-theory andsemi-experimental formulae have been obtained and established under the conditionof oil spill happened on static water or steady fluid flow mostly. In recent severaldecades, a lot of numerical models have been presented to simulate the fate andtransport of spilled oil.Oil transport and fate in the water is a complex process, including the physicalexpansion by gravity, surface tension, inertial force and viscosity force, chemicalchange resulted from weathering process, such as evaporation, dissolution,emulsification, photo oxidation and biodegradable, driftmotion caused by current andwind, as well as the randomness. The development of hydrodynamic models, such as the application of thetwo-dimensional hydrodynamic model ADCIRC, the three-dimensional hydrodynamicmodel FVCOM, and the three-dimensional hydrodynamic model HYCOM, provides agood basis for numerical simulation of oil spill accidents.For a rapid response to the oil spill accident occurred, A easy usingtwo-dimensional oil spill model with a friendly interface of NOAA, GNOME(General NOAA Operational Modeling Environment),is used to simulation oil spillaccidents.First, the work is to simulate the oil drift of “Deepwater Horizon”oil spill in Gulfof Mexico, occurred on April20,2010, with GNOME(General NOAA OperationalModeling Environment)model. The simulation time is from May4,2010to May11,2010. Ocean currents from GOM HYCOM outputs and winds from GFSR(ClimateForecast System Reanalysis) are used to drive the GNOME model during simulation.Comparisons between simulations and satellite observations are done and the resultsshow that the simulation agrees well with oil spill extent maps getting from thewebsite of Center for SatelliteBased Crisis Information. The effects from uncertaintyof ocean currents on the simulation results are also studied as well.Next, this paper chooses FVCOM(The Finite-Volume Coastal Ocean Model) tosimulate the hydrodynamic field of the Yueqing Bay. Comparisons between thesimulation results of the tide and the measured data are made, showing good results.The simulated current field is used as the driving field to simulate a hypothetical oilspill accident by GNOME model in the Yueqing Bay. This paper simulate different oilspill trajectory under different wind conditions(divided into static wind,wind in Ndirection, wind in SW direction and wind in NNE direction) separately, when the oilspill accident occurs at different tidal moments (high water and low water). Then thepaper discusses the influence factors of oil spill,and get a conclusion that all of thetidal time of oil spill accidents occur, the wind and the topography have an influenceon the oil drift trend and diffusion area and sweep area. The fate of oil spills underdifferent environmental conditions is also analyzed. A suggestion that combing building oil spill prediction model and theestablishment of oil spill monitoring system together, can make a more effectiveresponse to oil spill accident.