ASTM_F_2067_-_13.pdf

Designation:F206713Standard Practice forDevelopment and Use of Oil-Spill Trajectory Models1This standard is issued under the fixed designation F2067;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice describes the features and processes thatshould be included in an oil-spill trajectory and fate model.1.2 This practice applies only to oil-spill models and doesnot consider the broader need for models in other fields.Thispractice considers only computer-based models,and not physi-cal modeling of oil-spill processes.1.3 This practice is applicable to all types of oil in oceans,lakes,and rivers under a variety of environmental and geo-graphical conditions.1.4 This practice applies to two-dimensional models.Thereare three-dimensional models in the marketplace.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.2.Terminology2.1 Definitions:2.1.1 trajectory modela computer-based program that pre-dicts the motion and fate of oil on water as a function of time.2.1.1.1 DiscussionInput parameters include oil properties,weather,and oceanographic information.There are four differ-ent modes:forecast,hindcast,stochastic,and receptor.2.1.2 contingency planningplanning of several types toprepare for oil spills.2.1.2.1 DiscussionThis planning can include modelingsuch as described in this guide,to predict where oil spills mightgo and what the fate and properties of that oil would be.3.Significance and Use3.1 Trajectory models are used to predict the future move-ment and fate of oil(forecast mode)in contingency planning,in exercises and during real spill events.This information isused for planning purposes to position equipment and responsepersonnel in order to optimize a spill response.Oil-spilltrajectory models are used in the development of scenarios fortraining and exercises.The use of models allows the scenariodesigner to develop incidents and situations in a realisticmanner.3.2 Oil-spill trajectory models can be used in a statisticalmanner(stochastic mode)to identify the areas that may beimpacted by oil spills.3.3 In those cases where the degree of risk at variouslocations from an unknown source is needed,trajectory modelscan be used in an inverse mode to identify the sources of thepollution(hindcast mode).3.4 Models can also be used to examine habitats,shorelines,or areas to predict if they would be hit with oil from a givensource(receptor mode).4.Modelling Methods4.1 Models simulate the movement of oil on water,calcu-lates the various weathering processes and considers theinteraction of the oil with the shoreline.The input data neededby the model includes area maps,oil properties,and spatial andtemporal vectors of wind and ocean currents.In some models,there are separate programs for advection and fate.In somecases,the fate models calculate weathering on the total mass ofthe oil rather than on individual particles.Some models includeresponse strategies(skimming,burning,dispersing,and soforth)and the effect of these on the mass balance.4.2 The computer model calculates the surface fate of the oilusing physical and chemical properties of the oil and weath-ering algorithms.4.3 The output of a model is a map showing oil-slicklocations as a function of time,and graphs and tables of theweathering of the oil and mass balance.4.4 The output of the model is subject to uncertainties,primarily caused by uncertainties in the input data fromforecast winds and predicted ocean currents.The model shouldinclude an estimate of the magnitude of these uncertainties.Itshould be recognized that models are only a tool and thusoutputs should always be confirmed by ground-truthing.5.Input Modelling Parameters5.1 In order to generate a georeferenced output,it isnecessary to have a suitable base map.This map should have1This practice is under the jurisdiction of ASTM Committee F20 on HazardousSubstances and Oil Spill Response and is the direct responsibility of SubcommitteeF20.16 on Surveillance and Tracking.Current edition approved April 1,2013.Published April 2013.Originallyapproved in 2000.Last previous edition approved in 2007 as F2067 07.DOI:10.1520/F206713.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 a resolution in the order of 100 m near shore and 1 km in theopen ocean.The base-map data should be in a commonmapping format.The map should be vector-based in order thatthe output can be scaled to be consistent with the extent of thetrajectory.The data on the map should be organized in layers,with ocean current,wind fields,and trajectory informationavailable as separate layers.Other common layers are re-sources at risk,sensitive habitats,water inta