简介:TheprobabilityoffractaldeterminationofcoastaltypesbasedonGISispreliminarilydiscussedwithChinaasanexample.Finally,somesignificantconclusionsaredrawn:(1)Thefractaldimensionofcoastlineofthebedrockcoastislargerthanthatoftheplaincoastonthesamescalemap;(2)Asfarasthebedrockcoastisconcerned,thelargerfractaldimensionofcoastlineofthebedrockcoastonthesamescalemapindicatesthatthebedrockcoastisprobablynottypical;(3)Asfarastheplaincoastisconcerned,thesmallerfractaldimensionofcoastlineoftheplaincoastonthesamescalemapindicatesthatitisprobablythesiltplaincoast;(4)Thedifferentsubstantialcompositionsaffectthefractaldimensionsofcoastlinesofdifferentcoastaltypes.Ingeneral,thecoastwhichliesinthenorthoftheHangzhouBayconsistsofsandmainly,itssurfaceisflat,anditisconnectedwiththecoastalplain,itslandformisbroadshoal,itstotalchangeiscomparativelyhomogenousinthetidaldynamicprocess,andthus,therelativelysmallerfractaldimensionofcoastlineresultsfromthis.Forthebedrockcoast,thereismorebedrock,thecoastlineiscomparativelysmoothandstraight,beingaffectedbythefaultsandoceandynamicprocess,whichresultinthelargerfractaldimension.
简介:Aregionalgroundwatermanagementsystemhasbeenelaborated,integratingRelationalDatabaseManagementSystem(RDBMS)andvariouswebservices.Itconsistsofwebgeospatialapplicationso-calledHydrIS(HydrogeologicalInformationSystem)basedonOpenSourcecomponentsandtechnologies,leadingtoafeasibleandlow-costsolution.Therefore,HydrISpermitsdeliveryofdatafromanumberofheterogeneoussourcestostandardssupportedbytheOpenGeospatialConsortium(OGC).TheprotocolsusedforexchangingdataarealsoderivedfromOGCstandards,i.e.,WMS(WebMappingService),WFS(WebFeatureService),andWCS(WebCoverageService).Finally,ageoportalwasdeveloped,whichconsistsofclient-applicationsthatcommunicatewithdifferentWebServices(WMS,WCS,anAdWprFoSto)ttyhpreoufogrhwHeTbT-Pb-aresqeudeGstISs.applicationwasdesignedusingthedeegreeFrameworktoprovidesystematicinterfacesandfunctions.Thissystemwasdevelopedtodemonstratethevalueofmakinghydrogeologicaldatamorewidelyaccessiblethroughclient/serverarchitecture.Thisexperienceandknowledgealreadygainedinthisprojectwillbeasourcefortechnologytransferandpolicydecisions.Otherwise,thiswillenableusergroupstoimprovethemanagementoftheirground-waterresourcesandcontributetoenhanceddecisionsupportcapabilities.
简介:城市中心区等空间范围是城市研究中必须面对的基本问题。由于社会经济要素集聚的相对性和过渡性,城市中心区的位置和界线范围通常是不明确的,只有一个大致的范围,缺乏一个简单的确定方法。依据市政公用设施、地价、交通量等统计数据及其空间分布确定城市范围的传统方法工作量大、欠缺可比性。本研究以广州市城市道路网为数据基础,利用ArcGIS空间分析的密度分析方法圈定并验证了广州市城市中心区的边界范围。
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.