2 Introduction to GIS What is GIS ? An Information System that is used to input, store , retrieve, manipulate, analyze and output geographically referenced data or geospatial data, in order to support decision making for planning and management of land use, natural resources, environment, transportation, urban facilities, and other administrative records
3 Components of GIS Key components of GIS are: Computer system, geospatial data, and usersSources of geospatial data are:Digitized maps, aerial photographs, satellite images, statistical tables, and other related documentsComputerSystemGeospatialDataUsersFigure: Key components of GIS
5 Classification of Geospatial Data Graphical data (called geometric data)Attributes (called thematic data)Real WorldData ModelSpatial ObjectsPointsLinesAreasVectorRaster FormPixels inRasterAttributes in TablesFigure: Concept of Geospatial Data
7 Why GIS is needed ? Common problems of handing geospatial information: Geospatial data are poorly maintained.Maps and statistics are out of date.Data and information are inaccurate.There is no data retrieval service.There is no data sharing.
8 Benefits once GIS is implemented Geospatial data are better maintained in a standard format.Revision and updating are easier.Geospatial data and information are easier to search, analysis and represent.More value added product.Geospatial data can be shared and exchanged freely.Productivity of the staff improved and more efficient.Time and money are saved.Better decision can be made.
9 GIS Versus Manual Works MapsGISManual worksStorageStandardized and integratedDifferent scales on different standardRetrievalDigital DatabasePaper Maps, Census, TablesUpdatingSearch by ComputerManual CheckOverlayVery FastExpensive & Time consumingSpatial AnalysisEasyComplicatedDisplayCheap & FastExpensive
10 Comparison of Geospatial Information Management
11 Basic Functions of GIS Functions Sub-functions Data Acquisition and prepossessingDigitizing, Editing , Topology Building, Projection Transformation, Format Conversion etc.Database Management and RetrievalData Archival, Hierarchical Modeling , Network Modeling, Relational Modeling, Attribute Query, Object-oriented Database etc.Spatial Measurement and AnalysisMeasurement operations, Buffering, Overlay operations, connectivity Operations etc.Graphic output and VisualizationScale Transformation, Generalization, Topological Map, Statistical Map etc.
12 Computer System for GIS Hardware SystemCentral Processing Unit (CPU)Memory (RAM) > 64 MBI/O DevicePlotters, printers, mouse, digitizers, scanners, digital cameraSoftware SystemOperating SystemDOS, WindowsCompilerC++, Pascal, Fortran, BASICApplication ProgramsARC/INFO, MGE, Geo/SQL, GFIS, IDRISI*, GRASS** public domain software
15 Area of GIS Applications Facilities ManagementLocating underground pipes & cables, planning facility maintenance, telecommunication network servicesEnvironmental and Natural Resources ManagementEnvironmental impact analysis, disaster management and mitigationStreet NetworkLocating houses and streets, car navigation, transportation planningPlanning and EngineeringUrban planning, regional planning, development of public facilitiesLand InformationTaxation, zoning of land use, land acquisition
16 GIS Information Infrastructure PopulationLand UseCadastre etc.SocialInfrastructurePolice and FireCable and PipeTransportationsGISInformationInfrastructureEnvironmentalInfrastructureUrbanInfrastructureNatural ResourcesPollutionDisaster etc.EconomicInfrastructureEducationalInfrastructureMarketingBankingCar Navigations etc.Natural ResourcesPollutionDisaster etc.
17 GIS for decision support Human DimensionsPhysical DimensionsPopulationHealth & WealthTechnologyPoliticsEconomicDriving ForcesDevelopmentUrbanizationIndustrializationConstructionEnergyHuman ImpactsHumanActivitiesPublic AwarenessPublic ConcisenessPolicy MakingPlanningManagementLand Use ChangeChange of Life StyleLand DegradationPollutionClimate ChangeDecision MakingEnvironmental ChangeDatabaseAnalysis andAssessment by GISMonitoring byRemote Sensing