基于MAPGIS的分形方法确定化探异常

(:20010200015):2003211218;::,,1971,,;E-mail:[e-mail],,050031,,,,,,,r,N(r),,(GIS),rN(r),,,GIS,,MAPGIS,15Cu,MAPGIS,,,,,,,MAPGIS,,,(GIS)TheDeterminationofThresholdsbytheFractalMethodBasedonMAPGISLISuiminYAOShuzhenShijiazhuangCollogeofEconomy,Shijiazhuang,Hebei,050031AbstractThedeterminationofthresholdsofchemicalelementsisanimportantproblemsingeochemicalexploration.Atpresent,thereisnotasatisfactoryscientificwaytoconfirmthethresholds.Thetraditionalwayofdeterminingthresholdsofchemicalelementsisbasedontheassumptionthatchemicalelementsareinnormaldistributionorelementcontentsarecontinuouslychangedinspace.Nevertheless,thespatialdistributionofchemicalelementsisextremelycomplicated,andresearchesshowthatgeochemicallandscapemaybeachaoticsystemoflowdimension.Thebackgroundandanomalyvaluesofelementsusuallyshowindependentpowerindexre2lationship,resultinginthemultifractaldistributionofchemicalelements.Wecanthereforeusethefractalmethodofchemicalele2mentstodeterminethresholds.SeveralfractalmethodsfordeterminingthresholdsofchemicalelementsoftencomputerofdifferentscalesandthecorrespondingnumberofN(r).GeographicalInformationSystem(GIS)canrealizedynamicinquiryandattributeanalysisoffigureunits,andhenceGISisverysuitableforstatisticanalysisofrofdifferentscalesandcorrespondingN(r).Sowecancombinethefractalmethodwiththegeographicalinformationsystem.WithMAPGISgeographicalinformationsystemdesignedbyWuhanZondyInfo2EngineeringCo.Ltd.asanexample,ThispaperdealswiththedeterminationofthresholdsofchemicalelementsbyusingfractalmethodsbasedonGISplatform.Theresultsobtainedarecomparedwiththoseobtainedbytraditionalmethods.Thetraditionalmethodsfordeterminingthresholdsrequirepretreatmentoforiginaldataandconsiderationofpracticalgeologicalsetting.However,theoperationofthefractalmethodsbasedonMAPGISplatformisverysimpleandnotaffectedbyabnormallyhighvalues.Therefore,thefractalmethodsarelessaffectedbyartificialinterference.Acomparisonwiththetraditionalmethodshasledtotheconclusionthatthefractalmethodisaneffectivemethodfordeterminingthresholdsofchemicalelements.KeywordsGeographicalInformationSystem(GIS)fractalfractaldimensiongeologicalanomaly20054262:1872190ACTAGEOSCIENTICASINICAApr.200526(2):1872190,,,,()(X)2(1.53)(),,,,,,,,,,(1995)(D=2.9),1(Mandelbrot,1982):(),D,,,N(r)=Cr-Dr0,r;C0;D0;N(r)=N(r)rD,(N(r1),N(r2),,N(rn))(r1,r2,rn),,,DN(r1),N(r2),,N(rn))(r1,r2,rn),N(r)=Cr-D,,lgN(r)=-Dlgr+lgC,D,;,,,,,,r0i,Ei(i=1,2)E=E1+E2=i0i=1[lgN(ri)+D1lgri-lgC1]2+ni=i0+1[lgN(ri)+D2lgri-lgC2]2ri0;D1D2,,,ri0,ri0,ri0(1994),,(1994)22C=kAa,C;k;AC;a22MAPGIS,GIS,GIS,GIS,,MAPGISGISOMAPGIS,GIS2GIS28812005O.2000.EAPGIS.,,N(r)r,N(r)N(r1),N(r2),,N(rn))(r1,r2,rn),,:(1)MAPGISDTM,,5,ID(2),rrrDTMn120,50,r120170220r(1),r(3)(2),r,r(4)r,(GRAPHERSTATISTICA),D1D2,r1rFig.1Areaenclosedbycontourswhichhavecontourvaluesgreaterthanorequaltor315Cu,1337(3),(TL=x+2)Cu494.265002Cu2Cu(N=1337)11,lgrlgN(r),,:lgN(r)=-1.76858lgr+8.70177120r470lgN(r)=-4.9477lgr+16.59314470r2520(E=E1+E2)0.948,ri0470,Cu470(TL=X+2)Cu9812:MAPGIS12CuN(r)Table1N(r)ofCudatacalculatedbytheareamethodr/1026N(r)r/1026N(r)r/1026N(r)r/1026N(r)12055763.85201965.392059.817207.517055757.55701151.097048.818703.622055287.7620642.1102039.319203.127048265670396.7112027.220701.632031902720259.6132015.021201.437017610.6770158.9142012.922700.94208509.1820106.3147012.024700.44704103.687075.516708.325200.3500Cu4(1),,2(),,,2,(2),,(2)2lgN(r)2lgrFig.2FigureoflgN(r)2lgr.2002..:.,,.1999.ANN.:.ReferencesChenQM,AgterbergFP,BallantyneSB.1994.Theseparationofgeochemicalanomaliesfrombackgroundbyfractalmethods.Jour2malofGeochemicalExploration,51:109130.LiChangjiang,MaTuhua,ZhuXingshengetal.1999.Fractal,chaosandANNinmineralexploration.Beiing:GeologicalPublishingHouse(inChinesewithEnglishabstract).MandelbrotBB.1982.ThefractalgeometryofNature.W.H.Free2manandCo.,NewYork.ShenWei.2002.Fractalandchaoswithapplicationinmineralresourceprediction.Beijing:GeologicalPublishingHouse(inChinesewithEnglishabstract).0912005