简介:Ageographicinformationsystem(GIS)isahardware/softwaretoolwhichisveryeffectiveincollecting,storing,searching,handling,andvisualizinggeographicdatatogetherwiththeirdescriptiveattributes.Suchatoolisveryhelpfultoapproachawiderangeofsituations,includingmanylogisticproblems.ENEA,astheagencyhavingthetaskofimplementingtheItalianAntarcticProgram(PNRA),hasdecidedtouseaGIS,inordertoincreasetheefficiencyinmanagingthehugeamountofdatacollectedinthecourseofItalianactivityinAntarctica,whichcountsfifteenexpeditionsuptonow.
简介:阐述了传统GIS系统的不足及IntranetGIS系统的特点与组成内容,介绍了IntranetGIS系统建造时应注意的问题,同时提出了解决思路。
简介:Inordertosetupaconceptualdatamodelthatreflectstherealworldasaccuratelyaspossible,thispaperfirstlyreviewsandanalyzesthedisadvantagesofpreviousconceptualdatamodelsusedbytraditionalGISinsimulatinggeographicspace,givesanewexplanationtogeographicspaceandanalyzesitsvariousessentialcharacteristics.Finally,thispaperproposesseveraldetailedkeypointsfordesigninganewtypeofGISdatamodelandgivesasimpleholisticGISdatamodel.
简介:ThedevelopmentofInternetprovidesconvenientenvironmentforinformationsearchingandbrowsing.Italsoofferssanewplatformforgeographicinformationprocessingandanalysis.ThispaperdiscussesorganizationandprocessingapproachtoInternetgeographicinformation,andprovidesanewmethodtocross-platformanddistributedgeographicinformationanditssoftwareimplementation.Theexampieisusedtoshowthepracticalityandsuperiorityofthismethod
简介:ThisworkhasoriginallybeendoneintheP.R.China(WuhanTechnicalUniversityofSurveyingandMapping)andinHongKong(ChineseUniversityofHongKong).Prof.LinHuigaveusefuladvice.Mr.HanHaiyang,andMs.ChenLilihelpedworkwiththeimplementationofprototypesystem.WealsothanktheSwissNationalScienceFoundationforitsfinancialsupportandacknowledgethecommentsofDr.AndreasGeppertandProf.KlausR.Dittrichonanearlierversionofthispaper.
简介:东廷·莱克的沉积来自四条隧道(他们之一在1959被关上),与长江连接了,四条支流(Lishui,Yuanjiang,Zishui和Xiangjiang)和本地区域,和他们中的一些在Chenglingji被搬运进长江,它在东廷·莱克,的出口被定位他们中的一些在湖区域和剩余的存款扔进排水系统进湖。年度吝啬的沉积是166,555xl04t,80%来自四条隧道,18%从四条支流并且2%从本地区域,而26%全部的沉积被搬运进长江,74%扔了进湖和湖排水系统。基于上1974,1988和1998的地志的地图,和有地理信息系统(GIS)的空间分析方法,在沉积免职和侵蚀的变化在这份报纸被学习。由1974和1988的覆盖分析,1988和1998,侵蚀和沉积免职区域被定义。主要结论是:(1)在湖的沉积率比从1974~1998的侵蚀率大。在湖的吝啬的免职是0.43m;(2)年度沉积免职是在1974鈥?之间的一样988和1988鈥?998,但是免职的年度体积和998是的1988鈥?的侵蚀比那大在1974鈥?988;(3)在三的结束塞满水库以前,将有7.82xl08m3of沉积,在湖扔,它将由0.33m使湖成为silted起来;(4)在湖,免职区域在东方东廷·莱克,南方东廷·莱克的西南,和西方东廷·莱克的东方的北方被发现;当侵蚀的区域在东方东廷·莱克的南方时,南方东廷·莱克,西方东廷·莱克的西方,以及Xiangjiang和Lishui河洪水隧道的中间。
简介:当错误当模特儿在GIS描述曲线的错误,曲线的一个随机的错误过程被建议。以随机的进程,有关曲线的本地错误的四个特征也就是,意味着错误的错误功能,标准错误函数,绝对误差函数,和相关函数,被提出。一条曲线的全部的错误被随机的错误过程的吝啬的方形的积分表示。概率的意思和上面提及的特征的几何意思也被讨论。一个scandigitization实验被设计检查模型的效率。在实验,一条等高线被数字化因为超过100次和大量样品功能从实验被导出。最后,所有错误特征根据样品功能被估计。实验结果证明在数字化的地图数据的系统的错误不是可以忽略的,并且曲线上的点的错误主要依赖于弯曲和曲线的凹度。
简介:ThispaperfirstbrieflylooksbackonthehistoryofcensusGISaroundtheworld,andthensummarizessomepreponderancesofdevelopingurbancensusGISinChina.Andthenathree-tierconstructionarchitecturefortheurbancensusGISisproposed.Finally,usingtheillustrationofthecensusdataofGuangzhoucity,thepaperanalyzesandelaboratessomeissuesontheurbancensusGISdesigning,suchasdatamanagement,datawarehousebuilding,anddataanalysis.
简介:ThecurrentGIScanonlydealwith2-Dor2.5-Dinformationontheearthsurface.Anew3-Ddatastructureanddatamodelneedtobedesignedforthe3-DGIS.Thispaperanalyzesdiverse3-Dspatialphenomenafromminetogeologyandtheircomplicatedrelations,andproposesseveralnewkindsofspatialobjectsincludingcross-section,columnbodyanddigitalsurfacemodeltorepresentsomespecialspatialphenomenaliketunnelsandirregularsurfacesofanorebody.Anintegrateddatastructureincludingvector,rasterandobject-orienteddatamodelsisusedtorepresentvarious3-Dspatialobjectsandtheirrelations.Theintegrateddatastructureandobject-orienteddatamodelcanbeusedasbasestodesignandrealizea3-Dgeographicinformationsystem.
简介:I.IntroductionChangesinwetlandsplayanimportantroleinglobalchange.Moreandmoreatentionisbeingpaidtochangesinwetlandsandtheirimp...