1、Designation: F 2067 07Standard Practice forDevelopment and Use of Oil-Spill Trajectory Models1This standard is issued under the fixed designation F 2067; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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
3、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 e
4、nvironmental and geo-graphical conditions.1.4 This practice does not address issues of computeroperation. It is assumed that the user of this practice is familiarwith the use of a computer and its operating systems.2. Terminology2.1 Definitions:2.1.1 trajectory modela computer-based program thatpred
5、icts the motion and fate of oil on water as a function oftime. Input parameters include oil properties, weather, andoceanographic information. There are four different modes:forecast, hind cast, stochastic, and receptor.3. Significance and Use3.1 During an oil-spill response, trajectory models are u
6、sedto predict the future movement and fate of oil (forecast mode).This information is used for planning purposes to positionequipment and response personnel in order to optimize a spillresponse.3.2 Oil-spill trajectory models can be used in a statisticalmanner (stochastic mode) to identify the areas
7、 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 possible sources ofthe pollution (receptor mode).3.4 Oil-spill trajectory models are used in the developmen
8、tof scenarios for training and exercises. The use of modelsallows the scenario designer to develop incidents and situationsin a realistic manner.4. Modelling Methods4.1 A typical model simulates the motion of oil on water,calculates the various weathering processes and considers theinteraction of th
9、e 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 oi
10、l rather than on individual particles.4.2 The computer model calculates the fate of the oil usingphysical and chemical properties of the oil and weatheringalgorithms.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
11、.4.4 Trajectory models operate in a number of modes;predictive, stochastic and receptor.4.5 The output of the model is subject to errors, primarilycaused by errors in the input data from forecast winds andpredicted ocean currents. The model should include an esti-mate of the magnitude of these error
12、s.5. Input Modelling Parameters5.1 In order to generate a georeferenced output, it isnecessary to have a suitable base map. This map should havea resolution in the order of 100 metres near shore and 1 km inthe open ocean. The base-map data should be in a commonmapping format, for example MID/MIF, AR
13、C, and DIF. Themap should be vector-based in order that the output can bescaled to be consistent with the extent of the trajectory. Thedata on the map should be organized in layers, with oceancurrent, wind fields, and trajectory information available asseparate layers.5.2 The physical and chemical p
14、roperties of the oil areneeded in order to calculate the weathering of the oil. This datashould be derived from readily available distillation datacurves and other standard oil-industry crude descriptors. Cata-logues are available that include parameters used in oil-spilltrajectory models. The need
15、for the determination of specialparameters should be avoided where possible.5.3 The spatial and temporal distribution of wind fields isrequired to drive the advection terms of the model. These windfields should be input as a time series of vectors, with separateinputs for each wind-data source. The
16、modeling program1This 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, 2007. Published April 2007. Originallyapproved in 2000. P
17、reviously approved in 2006 as F 2067 00 (2006).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.should have methods to interpolate the data from the individualwind observations. In some cases, weather data would beavailable as large s
18、cale synoptic charts. The computer programshould be able to translate these maps into the required windfields.5.4 The ocean current regime can be divided into threecomponents: wind-driven currents, tidal currents, and residualcurrents.5.4.1 The vector sum of these three currents is the spatialand te
19、mporal driving force that moves the oil on the oceansurface. The total ocean current equation must obey thecontinuity equation so that the model does not generateartificial sources and sinks. The wind-driven currents aredirectly mapped from the wind field, with a factor of about3.5 % commonly used t
20、o convert the wind vector into thecorresponding surface ocean-current vector.5.4.2 The ocean-current vectors that are produced by tidalaction are strongly dependent on the bathymetry and shorelineshape of the area involved. Tidal currents follow the tidalperiod, with strong spatial changes depending
21、 on the tidalcycle. There are many schemes that have been derived tocompute such currents.5.4.3 The residual currents are strongly spatially dependentbut remain constant in time over the duration of most spillmodel calculations. This may not be true for stochasticcalculations that have time periods
22、of months to years.5.4.4 In estuaries and many other situations, there are verycomplex currents, which cannot be reliably represented byavailable models.5.4.5 The computation of ocean currents is complex andshould be supplemented by actual measurements using drifterbuoys and oceanographic current me
23、ters. In many situations,simple current measurement using floating objects can be usedand are better than no measurements.5.5 There are many limitations to the ability of models topredict oil motion and the output should be regarded asguidance rather than an absolute prediction.6. Model Characterist
24、ics6.1 Most models divide the slick into a number of particles,each of which is advected and weathered separately. Theseparticles are treated as moving elements. The real slick iscontinuous and not quantized. If insufficient particles are usedby the mode, then anomalous results are generated. The to
25、talnumber of particles in the system should be greater than 100 atall times.6.2 Models should allow the review of the data at any time.This implies a multiwindow operating environment. The tra-jectory and weathering data should be visible during thecalculations.6.3 The model should include the weath
26、ering of the oil withtime. Essential processes are, in order of importance for mostoils:6.3.1 Evaporation,6.3.2 Dispersion,6.3.3 Dissolution, and6.3.4 Emulsification.6.4 The beaching of oil on shorelines should be indicated asa change in the shoreline properties. The retention of oil by theshoreline
27、 should be characteristic of the shoreline and derivedfrom the shoreline layer on the map. If this data is notavailable, a global default value should be used.6.5 The model should have the capability of includingexternal observations, such as data from remote sensing, toadjust the output of the mode
28、l to conform to the newinformation. The model should automatically adjust to reflectthe new observations.6.6 The model should calculate the confidence limits of theoutput.7. Model Output7.1 The model output should be presented on a map of thearea. This map should be derived from a GIS, with layers f
29、orthe trajectory modes, input wind data, input ocean currents, andconfidence levels of the predictions. Weathering should bepresent as a time series graph and in tabular form.7.2 The model output should be available in a color formatfor local use and e-mail transmission.7.3 The output of the model a
30、nd its maps should be easilytransferable to other computer-based documents, such as word-processing and GIS programs, for the incorporation intoreports.7.4 The output of the models should have provisions forannotation and have standard blocks for user information.7.5 Estimates of errors for both the
31、 motion and weatheringof the oil should be clearly indicated on the output.8. Keywords8.1 computer-based model; oil spill surveillance and track-ing; oil spill trajectoryASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
32、 this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and mus
33、t be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the
34、responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F2067072
