뗚16뻭뗚1웚믰ꆡꆡ퓖ꆡꆡ뿆ꆡꆡ톧,쓪1퓂컄헂뇠뫅:100425309(2007)20001209ASpreadModelforForestFireBasedonComputerGraphicTechniquesQINXiang2dong1,2,MinQin2weng1,Abu3liti,LINQi2zhao4(,CAS,Beijing100101,China;,Beijing100049,China;(AIRC),421126Daini2tonyacho,Aomori03020113,Japan;,USTC,HefeiAnhui230026China)Abstract:Twospreadmodelsfrequentlyusedforforestfiresimulation,namelythecontiguouscellularmodelandthewavepropagationmodel,stronglycomplementeachotherintheiradvantagesanddisadvantages,thisisutilizedinthispapertodesignaspreadmodelbasedoncomputergraphictechniques,,,includingeffectonlocaldistortionandaberrationofthefireline,,itisdeducedthatthenewmodelgreatlyimprovestheperformanceofcomputersimulationforforestfirespreadsothatitcanprovideforestfirefighterswithprecise,overalldiagramsoffiredevelopmentinrealtime,:forestfire;computersimulation;spreadmodel;computergraphics0ꆡstudyontheinteractionprocessesbetweenforestIntroductionfireenvironmentandfirebehavior,modelsintheInourtime,,overalldiagramoffiretheotherhand,thepoorperformanceofreal2time,developmentinrealtimeisakeyissuefordecision2precision,reliabilityandfullyflexibilityforthemakingduringforestfirefighting[1,2].Accordingsystemismainlyduetonothavingestablishedantothehierarchyofforestfiresimulation,theefficient,precise,reliableandflexiblespreadsystemforsimulationisdividedintothreelayers:,amathematicalshapemodels,computeralgorithmsofthespreadmodelinthemiddlelayercalculatedonfireareamodelaredesignedinordertosimulatetheshape,,,thereReceived:2006209212;Revised:2006212210Foundationitem:ResearchProgramoftheMinistryofScienceandTechnologyofChina(97322002CB111506)
2믰퓖뿆톧ꆡFIRESAFETYSCIENCE뗚16뻭뗚1웚,namelythecontiguousundersomecomplexconditions,,isThecontiguouscellularfirespreadmodelsimulatedwiththenewmodeltoshowitshighbasedonautomachine,,eachwithaninitial1ꆡꆡꆡThepresentwavepropagationmodelbasedonpossiblemomentoffirereachcorrespondingtoindependentpointsourcehypothesisusesthefireeachcellisreadandwriteduringfirespread[3ꆫ5].,fireareaisandGuertinthinkthatdiscretizationoffireareaexpressedbyborderlinecomposedofvectorandcorrespondingfirereachmomentaccordingtocoordinates,]arameterstotimeatafireareaborderlin[6e,highlyreducestheefficiencyandreliabilityofalthoughsomeimprovementsatthecostofmuchalgorithms,,Frenchthewavepropagationmodel,thecontiguousconcludesthatnosuchcontiguouscellularmodeliscellularmodeldoesnꆯthavethesedisadvantages,suitableforpracticalspreadsimulationoffirewhileinherentlimitofthecontiguouscellularunderinhomogeneousspatio2temporalcondi2modelsuchaslowprecisioncomesfromlackoftion[7],Huygensprincipletospreadsimulationofsurfaceusingcomputergraphictechniquestoovercomeitsfire,andofferedwavepropagationmod[7,8],modelisasfollows:withinwhichfireenvironmentparametersare(1),currentborderlineasindependentfiresources,,makinguseofbemuchhigherthandensityofthecells,.(2)AddfireareashapemodeltotheThisarticletakesaimatthedisadvantagesandcontiguouscellularmodel,,incorporatingsomeadvantagesdefinitionofcontiguouscellsinthecontiguous
(3)Insteadofcalculatinginrealtimethethesefirebehaviorparameters,timestepandmapfunctionfieldofthepointsource,utilizesimilarityscale,[9]estopre2calculatelotsoffirearea(3)Writeaseriesofmetagraphicstothegrayshap[10]es,andsavetheresultsinformoflevelimageaccordingtogivenrulesofrastergraphics,whichcanbeuseddirectlyandoperation(illustratedasFig13b,,therehavenotmetagraphicswithenough(4)Now,theoverlapsoffunctionfieldofdensity.),soastosetpixelscoveredbythepointsources,whichrepresentsfire2acrossarea,metagraphicstolevel4(illustratedasFig13c).aretranslatedintographicpixelgridoperations(4)Regardingallpixelsthatarenotlevel4aswhilesolvingtheenvelopinglineistranslatedintobackground,searchou11]tlinesoftheimag[e,,(5),maybeapartofpixelsoftheoutlinesberesettolevel2orlevel4,asFig13e2ꆡ(1)to(5)ꆡPrimarystepsgoesthroughagiventimeorthereisnopixelofFirst,ꆡDealingmethodofthecomplextopologyprecision,ꆡꆡExpressionofvectorcoordinatesonmetagraphicsetofellipticshapesdiscretizedborderlineshavingbeengivenup,thereisnoneedaccordingtotheirmajoraxis,,,calculatedonlyonceatthecreationofthewholesuchasself2crossoversofborderlines,,unburnedenclaveandsimulationSecond,mapthegeographicalelementstoaforspottingfire,,themappingtransformintothegraylevelimage,theflood2fillalgorithmtograylevelimage,whichhasonlytwolevels,,,setpixelslocatedinfireignitiongeographicelements,withoutadditionalvectorsourceinthegraylevelimagetolevel3(,startingborderline).Thenrepeatthefollowingsteps,asattheseedpixel,,ascan2lineflood2fill(1)Calculatefirebehaviorparameterssuchasalgorithm[12]isusedtofillgrayoflevel4,ROSm,,forpixelsofregardingpixelsoflevel1(unburnable)andthoselevel3inthegraylevelimage,,afirebreakfromthe(2)Fetchcorrespondingmetagraphicsfromlowerrightcornerandazigzaggingroadtogether
4믰퓖뿆톧ꆡFIRESAFETYSCIENCE뗚16뻭뗚1웚
,ꆡProjectiontransformationmethodwaterareasnearby,,andshouldbeafireareashapecenteredonpointsourcePdivideprojectedtoahorizontalplaneinmostspreadeachotherinto9domains,,,whichneedtobeprojectedtoforaflood2fillalgorithmofhorizontalscan2lineathorizontalplane,ꆡProjectiontrꆡ,,correspondingtrianglealgebraInthespreadmodelbasedongraphicconversiondeterminedbyparameterssuchasslopetechniques,itisunnecessarytoacquireanalyticgradientandazimuth,,andeccentricitybeforeprojection,issoInstead,thealterationoffireshapefromslopetocomplexandinefficientthatanapproximatehorizontalplanecanbelookedasthecombinedcalculationhadtobeadopted,supposingthatthetransformationofgraphicrotationandshear,,andthentransformsthemButforamorecomplexfireareashape,itstothoseinhorizontalplane,,
6믰퓖뿆톧ꆡFIRESAFETYSCIENCE뗚16뻭뗚1웚ꆡAdvantagesandDisadvantagesofSpreadMAswiththemodelintoplayer,ꆡAdvantagesoftheNewModelsimulationsystemhasimprovedasfollows:Thenewmodelrequiresnocalculationfor(1)Theperformanceofthewholespreadtopologyrelations,whichhasthreefollowingsimulationisindependentofcomplexityoffireadvantages:behaviors,whichfacilitatesthespreadsimulation(1).(2)Improvementsinfireareashapemodeldo(2).(3)Theperformanceofthewholespread(3)Theresultisthatthelayerstructureofthesimulationisindependentofcomplexityofthewholesimulationsystemismoredistinctandmoregeographicelements,ꆡLocalDistortionandAberrationThefollowingtwoadvantagesareduetotheTheoriginalwavepropagationmodelmetagraphicset:approximatespolygonswithafinitenumberof(1)Calculationsforfireareashapesandtheirverticestofirearea;thismayleadtolocalenvelopinglineareunnecessaryduringsimulationdistortiononborderlines,illustratedinthelefthalfofspreadsotheefficiencyisimprovedmuchmoreofFig16,(2)Goodflexibilityisachievedbecausethetime,ꆡEliminationoflocalborderlinedistortionꆡꆡInthenewmodel,enoughmetagraphicsoffireensuresthatthedistortionerrorbelimitedontheareashapesareinsertedalonglineAB,(forclarity,ꆡAnalysisofMainDisadvantagesoftheNewmetagraphicsisillustrated).SegmentA1B1ontheModelborderlineatthenextmomentisgetbymeansofꆡꆡBecauseofinherentlimitationofthesearchingoutlineofthesemetagraphics,regardlessindependentpointsourcehypothesis,(seenextoriginalmodel,neitherdifferenceoftheinitialsection),justastheoriginalmodel,themethodspreadaccelerationasaresultofdifferentignition
,nordifferenceofpropagationspeedand4ꆡAnalysisofaCasestudyaccelerationowingtodifferentlocalshapeofborderlinesegments,ꇁ0kmareainMoreover,iftheparametersofthelocalfireQingyangcounty,Anhweiprovince,China,environmentvaryextremely(),,thelimitationoftheatthebeginning,andthenveersslightlytotheindependentpointsourcehypothesis,bynature,east,().Thus,ꆡAforestfiredevelopmentchartinQingyangcountyinAnhui,ChinaꆡꆡTheupperleftsectionofthefigureshowsantwentyminutesbecauseofspottingthatleadtosixunburnedenclavenearahilltoponthenorthernnewfiresources,
8믰퓖뿆톧ꆡFIRESAFETYSCIENCE뗚16뻭뗚1웚,asuitabletooverallsimulationoveralongperiodofdiscretemodelasitis,ꆡConclusionsingaPCwithPentium4,117GHzCPU,thespreadsimulationtakes35secondsinthiscase,,thenewmodelcanbeadvantagesofthecontiguouscellularmodelandthecalculatedfasterthanthepreviousmodelsbymorewavepropagationmodel,:forforestfirespread,suchasprecision,efficiency,(1)Addorsubtractseveralfiresources,orreliability,,,.(2)ConsiderorignorerestrictionofriversandAsaresult,,,multiformfire(3)Discountspottingleadtosomenewfirebehaviorsandcomplexgeographicalelementsonasourcesornot(,asabehavioritself).Thisindicatesthatthemodelinthetoplayer,(4)Takeintoaccountunburnedenclaveand/[1]LinQizhao,[M],[6]BallGL,,1stedition,.[J],(2):47ꆫ54.[2]StephenJP,[M].[7]&SonsInc.,[A]..[3]Kourtz,,AustralianfiretosimulateburnedandburningareasforuseinaDefenceForceAcademy[C],[J].(2):163ꆫ[8][J].USDAForestService.[4]Kourtz,P,[9][J].[J]..[5][10][J].:21ꆫ[J].
,5(2):63ꆫ,2001,583.[11]SunJiaguang,[12]DonaldHearn,,(3rdedition)[M],publishingcompanyofTsinghuaSecondEdition[M].PearsonEducation,.믹폚볆쯣믺춼탎벼쫵뗄쇖믰싻퇓쒣탍쟘쿲뚫1,2,쟬컄1,낢늼샯쳡3,쇖웤4(1.훐맺뿆톧풺뗘샭뿆톧폫풴퇐뺿쯹,놱뺩100101;2.훐맺뿆톧풺퇐뺿짺풺,놱뺩100039;3.쟠즭릤튵ퟛ뫏퇐뺿쯹,쟠즭쫐뗚뛾볤컝4뚡쒿11랬6뫅죕놾쟠즭03020113;4.훐맺뿆톧벼쫵듳톧죈뿆톧뫍쓜풴릤돌쾵,낲믕뫏럊230026)햪튪:쒿잰폃폚쒣쓢쇖믰싻퇓뗄쒣탍훷튪쫇쿠쇚떥풪쒣탍뫍늨뒫능쒣탍,쯻쏇뗄폅좱뗣뻟폐쏷쿔뗄뮥늹탔ꆣ놾컄믹폚볆쯣믺춼탎벼쫵,뾼싇틑폐쒣탍뗄폅뗣,짨볆쇋튻룶탂뗄싻퇓쒣탍ꆣ놾컄뷩짜쇋탂쒣탍뗄짨볆랽낸폫쪵쿖랽램,틔벰펰짤뇤뮻,췘웋맘쾵뗄뷢뻶랽낸ꆣ퇐뺿쇋쯼쏇뗄폅좱뗣틔벰믰쿟뗄쪧헦뗈컊쳢ꆣ춨맽샭싛럖컶뫍낸샽퇐뺿,탂쒣탍듳듳룄뷸쇋쇖믰싻퇓뗄볆쯣믺쒣쓢맽돌,틲듋놾쒣탍뿉늻쫜뗘샭뮷뺳뫍믰탐캪뢴퓓탔뗄쿞훆,쳡릩쇖믰랢햹뗄쪵쪱좫뺰춼쿳ꆣ맘볼듊:즭쇖믰퓖;볆쯣믺쒣쓢;싻퇓쒣탍;볆쯣믺춼탎톧훐춼럖샠뫅:S7ꆡꆡꆡ컄쿗뇪쪶싫:A
ퟷ헟볲뷩:쟘쿲뚫(1971ꆪ),쓐,붭쯕죋,ퟷ헟볲뷩:쟼샻뻪(1972ꆪ),얮,헣붭쪡충훐맺뿆톧풺뗘샭뿆톧폫풴퇐뺿쯹퓚뛁늩쿧쫐,헣붭듳톧뫳쟚맜샭뒦뷚쓜맜샭냬릫쪿짺,훷튪퇐뺿랽쿲캪뺰맛짺첬맦뮮뫍즭쫒훷죎ꆣ릤돌쪦,튻벶쿮쒿뺭샭,힢닡퓬볛쇖믰퓖뗄볆쯣믺쒣쓢ꆣ릤돌쪦,튻벶붨퓬쪦횴튵룱,듓1997쓪뾪쪼튻횱듓쫂붨훾쿻럀낲ힰ쿮쒿짨볆폫쪩릤맜샭릤ퟷ,붨훾뷚쮮업쮮짨볆ꆢ쪩릤,훷돖뛠쿮릫폃폫쏱폃붨훾뷚쮮뷚쓜룄퓬쿮쒿ꆣퟷ헟볲뷩:쳯쿾죰(1971ꆪ),쓐,즽뚫맚쿘ퟷ헟볲뷩:쇖쇺(1981ꆪ)쓐,몺ퟥ,쿖캪죋,늩쪿,뢱퇐뺿풱ꆣ훷튪듓쫂즭쇖믰퓖풤훐맺뿆벼듳톧믰퓖맺볒훘뗣쪵퇩쫒쮶쪿퇐럀랽쏦뗄퇐뺿,닎폫맺볒뿆벼릥맘쿮쒿ꆢ뺿짺,훷튪퇐뺿랽쿲:틵좼쿲폐퇦믰뮯뗄ꆰ948ꆱ틽뷸뫍ꆰ973ꆱ믹뒡퇐뺿쿮쒿뗈퇐뺿릤퇐뺿ꆣퟷꆣퟷ헟볲뷩:췵쏷폱(1976ꆪ),쓐,즽뚫쇺뿚ퟷ헟볲뷩:컌솢볡(1961ꆪ),쓐,릫낲늿짲죋,훺샭퇐뺿풱,퓚뛁늩쪿,훷튪듓쫂즭쇖퇴쿻럀퇐뺿쯹뢱퇐뺿풱,훷튪듓쫂믰퓖첽믰퓖,GIS뫍RS펦폃퇐뺿ꆣ닢놨뺯벼쫵퇐뺿벰닺욷뾪랢뫍릤돌펦폃릤ퟷꆣퟷ헟볲뷩:뗋쿦(1968ꆪ),쓐,뫾쓏짛퇴ퟷ헟볲뷩:좽몣뎱(1964ꆪ),뫓놱뿆벼듳톧죋ꆣ훐쓏쇖튵뿆벼듳톧즭쇖럀믰퇐뺿쫒뢱뷌쫚,짏몣붻춨듳톧킣췢늩쪿짺떼쪦,뫓놱뷌쫚,쮶쪿퇐뺿짺떼쪦,짺첬톧늩쪿퇐뺿쪡붨훾럀믰볒캯풱믡캯풱ꆣ퇐뺿쇬폲캪짺,훐맺쿻럀킭믡즭쇖럀믰튵캯풱믡캯붨훾컯믰퓖퓧웚헯뛏폫뿘훆벼쫵,믱뗃뫓풱ꆣ훷튪퇐뺿랽쿲캪쇖믰짺첬톧뫍탅쾢짺놱쪡뿆벼뷸늽뛾ꆢ죽뗈붱,뫓놱쪡뷌폽쳼뿆첬톧ꆣ벼뷸늽죽뗈붱뗈ꆣ듋췢,믱ힼ샻솽쿮ꆣ퓚쏀맺훘튪맺볊톧쫵웚뾯ꆢ맺볊믡틩ꆢ맺볒벶톧놨짏랢뇭싛컄15욪,놻SCIꆢEIꆢISTP쫕슼7욪ꆣퟷ헟볲뷩:샮쮼돉(1977ꆪ)쓐,몺ퟥ,즽뚫?돇죋,2000쓪뇏튵폚맾뛻뇵릤튵듳톧,놾ퟷ헟볲뷩:튦뇳(1971ꆪ),쓐,늩쪿,훐맺뿆뿆,쿖캪훐맺죋쏱커ힰ뺯달늿뛓톧풺쿻럀톧벼쫵듳톧믰퓖뿆톧맺볒훘뗣쪵퇩쫒뢱뷌횸믓쾵붲쪦,훐맺뿆톧벼쫵듳톧믰퓖뿆톧쫚,힢닡낲좫릤돌쪦,훐맺뿆톧풺죈낲좫릤맺볒훘뗣쪵퇩쫒쮶쪿퇐뺿짺,훷튪듓쫂퇌돌벼쫵퇐뺿훐탄뢱훷죎,훐맺쿻럀뇪ힼ뮯웸뿘훆폫쮮엧쇜쿠뮥ퟷ폃뗄퇐뺿ꆣ벼쫵캯풱믡뗚웟럖벼쫵캯풱믡캯풱,맺볒ퟔ좻뿆톧믹뷰훘듳맺볊뫏ퟷ퇐뺿쿮쒿ퟓ쿮쒿뢺퓰죋ꆰ,973ꆱ믰퓖쿮쒿퇐뺿맇룉ꆣ훷튪ퟷ헟볲뷩:헔컄뮯(1966ꆪ),쓐,뫓쓏뾪럢퇐뺿랽쿲캪붨훾믰퓖낲좫폫쏰믰탂벼쫵풭샭,랢뇭톧쫵싛컄죋,톧쪿,릤돌쪦ꆣ쿖릤ퟷ떥캻쫇맺볒컀탇60폠욪,믱맺볒뿆벼뷸늽뛾뗈붱튻쿮ꆣ웸쿳훐탄맣훝웸쿳컀탇뗘쏦햾,맺볒뿕볤쳬웸풤뺯훐탄맣훝쟸폲훐탄ꆣ쿖훷튪듓쫂웸쿳컀탇튣룐펦폃퇐뺿뫍웸쿳컀탇뿕볤쳬웸풤뺯퇐뺿ꆣ퓰죎뇠벭:돂ꆡ뻼펢컄뇠벭:쇵쓋낲
