简介:AnOracle8i-basedap-proachisproposedtomanagetheinte-grateddatabasesoflargeCyberCity.Thisapproachconsistsofthreeisdesignedtoacceleratespatialretrieving,inwhichtheboundingboxesoflocalregionshavenointersectionandallleafnodesoftheR+-tree(geome-tryrecords)havenorepetition;rithmsareadoptedtocompressthedigitalelevationmodels,3Dvectormodelsandimages,suchasLZ77losslesscompressionalgorithmforcompressionofvectordataandJPEGcompressionalgorithmsfortextureim-Oracle8idatabase,aCyberCityGISspatialdatabaseengine(SDE)isdesigned.OnthebasisofthisSDEpro-totypeacasestudyisdone.
简介:ThispapercomparesthedifferencesbetweenthemathematicalmodelingraphtheoryandGISnetworkanalysismodel.ThusitclaimsthattheGISnetworkanalysismodelneedstosolve.Thenthispaperintroducesthespatialdatamanagementmethodsinobject-relationdatabaseforGISanddiscussesitseffectsonthenetworkanalysismodel.FinallyitputsforwardtheGISnetworkanalysismodelbasedontheobject-relationdatabase.Thestructureofthemodelisintroducedindetailandresearchisdonetotheinternalandexternalmemorydatastructureofthemodel.Theresultsshowthatitperformswellinpractice.
简介:[35]BraunM,RauF.Usingamulti_yeardataarchiveofERSSARimageryforthemonitoringoffirnlinepositionsandablationpatternsontheKingGeorgeIslandicecap(Antarctica).TheWorkshopofEARSeLSpecialInterestGroup:RemoteSensingofLandIceandSnow.Dresden,2000(publishedonCD_Romin2001)[36]RauF,BraunM,FriedrichM,etal.Radarglacierzonesanditsboundariesasindicatorsofglaciermassbalanceandclimaticvariability.TheWorkshopofEARSeLSpecialInterestGroup:RemoteSensingofLandIceandSnow.Dresden,2000(publishedonCD_Romin2001)[1]BahrDB.Globaldistributionofglacierproperties:Astochasticscalingparadigm.WaterResourceResearch,1997,33(7):1669~1679[2]BahrDB,MeierMF.Snowpatchandglaciersizedistributions.WaterResourceResearch,2000,36(2):495~501[3]BraunM,SchneiderC.CharacteristicsofsummerenergybalanceonthewestcoastoftheAntarcticPeninsula.AnnalsofGlaciology,2000,31:179~183[4]BraunM,RauF,SaurerH,etal.ThedevelopmentofradarglacierzonesontheKingGeorgeIslandIceCap(Antarctica)duringtheAustralsummer1996~1997asobservedinERS_2SARdata.AnnalsofGlaciology,2000,31:357~363[5]CalvetJ,CorberaJ,FuradaG.VariaciondelfrenteglaciarenBahiaSuryPuntaSiddonsentre1956y1991,IslaLivingston,IslasShetlanddelSur.In:López_Martinez,J.:GeologíadelaAntártidaOccidental.IIICongresoGeológicodeEspanayVIIICongresoLatinoamericanodeGeología,Salamanca,Espana,1992.283~292[6]DoakeCSM,VaughanDG.RapiddisintegrationoftheWordieIceShelfinresponsetoatmosphericwarming.Nature,1991,350(6316):328~330[7]DoakeCSM,CorrHFJ,RottH,etal.Break_upandconditionsforstabilityofthenorthernLarsenIceShelf,Antarctica.Nature,1998,391:778~780[8]FoxAJ,CooperAPR.Climate_changeindicatorsfromarchivalaerialphotographyoftheAntarcticPeninsula.AnnalsofGlaciology,1998,27:636~642[9]HarangozoSA,ColwellSR,KingJC.Ananalysisofa
简介:本文探讨了应用一种新的计算机技术─地理信息系统(GIS),管理地震烈度衰减信息。系统以34°─41°N、110°─120°E范围内的41幅等震线图为数据基础建造了地震烈度衰减信息系统研究原型IAIS,重点在于利用、发掘GIS在管理、应用地震烈度衰减信息方面的能力。系统以GISI具软件ARC/INFO为开发平台,将每一幅等震线图存贮为一个专题图层,建立拓扑结构确定等震线特征之间的空间关系。等震线图中所表示的描述性特征存入特征属性文件,并通过一个共同的项使等震线和烈度分区与属性表中的描述建立了一一对应的关系。系统提供了从震中分布图或地震序号、发震时间等查询、显示各个等震线图的功能,并可以交互式地量算各等震线的长、短半轴,自动量算各烈度区的面积等。针对将不同比例尺、不同投影方式及不同投影参数的等震线图转绘编制综合等震线图的主要困难,本文研究了ARC/INFO中的投影转绘问题。系统按“留大舍小”的原则自动生成综合等震线图。同时,IAIS实现了综合等震线图的计算机管理,包括显示、查询、局部修改、统计量算等。
简介:GIS人才的培养目前主要分为三个层次,即科研型、开发型和应用型,其数量应呈金字塔形,应用型人才的数量最大,根据今后GIS的普及和推广,种类应用型人才的需求量会不断增加,本文重点分析了GIS应用型人才培养的重要性、可行性,阐述了培养CIS应用型人才应做的工作.
简介:ABSTRACT AGISisproposedasatoolforthemanagingplanfortheAntarcticspeciallymanagedarea(ASMA)inAdmiraltyBay.TheASMAcomprisestheareaconsideredtobewithintheglacialdrainagebasinofthebay.Furthermore,itincludespartofSSSINo.8adjacenttotheareabutoutsideoftheglacialdrainagebasin.Threestationsandsixrefugesarelocatedinthearea.UsingaSPOTsatelliteimagemap,thelimitsoftheASMAaremarkedanditsareaisre_calculated.Itconsistsof362km2,including186km2islandicefieldandsmallcirqueglaciersand32km2ice_freefield.Therestcompriseswaterofthebayandasmalladjacentarea(8km2)oftheBransfieldStrait.TheASMA_GISwillconsistsof12datalayersrangingfromthephysiographicsettingstothebiologicalandadministrativefeatures.AlldatawillbeimplementedintoArc/InfoGISaccordingtothecartographicguidelinesoftheSCARWG_GGI.First,fiveplansofinformationwillberealisedusingatopographicdatabasecompiledfromvarioussourcesanddatafromtherevisedbathymetricchartpublishedbytheBrazilianNavyHydrographicSurveyandalsoincluding:1)LimitsoftheASMAandprotectedareas;2)Glaciologicalfeatures(e.g.drainagebasinlimits)and3)Humanpresence(e.g.stationsandhistoricalsites).ThesebasicGISlayerswillbeoperationalinearly2001.Then,additionaldataontheremaininglayers(e.g.hydrology,geologyandgeomorphology)willbeincludedfrompublishedsources.TheASMA_GISwillformanimportantdatabaseforenvironmentalmonitoringandstudiessurveyingtemporalchangesoffeaturessuchasglacierfrontpositionsorbirdbreadingsites.
简介:Theauthorsstudythestructure,functionsanddataorganizationforthehazardanalysissystemofurbanpost-earthquakefireontheplatformofGIS.Ageneralhazardanalysismodelofthepost-earthquakefireispresented.TakingShanghaicentraldistrictasbackground,asystemforhazardanalysisofthepost-earthquakefireandauxili-arydecision-againstfireisdeveloped.