CES – VCU April 2005 William Shuart Center for Environmental Studies Virginia Commonwealth University An introduction to Geographic Information Systems
CES – VCU April 2005 What is GIS? A method to visualize, manipulate, analyze, and display spatial data
CES – VCU April 2005 What is Not GIS??? GPS – Global Positioning SystemGPS – Global Positioning System A static map – paper or digitalA static map – paper or digital –Maps are often a “product” of a GIS –A way to visualize the analysis A software packageA software package
CES – VCU April 2005 Spatial Data Estimates are that 80% of all data has a spatial componentEstimates are that 80% of all data has a spatial component –Data from most sciences can be analyzed “spatially”
CES – VCU April 2005 Databases Not easy to interpretNot easy to interpret –Attribute values
CES – VCU April 2005 Visualization A picture is worth a thousand wordsA picture is worth a thousand words
CES – VCU April 2005 Query Analyze StoreDisplay Capture Output GIS Functions
CES – VCU April , , , , , Coordinates Coordinates Paper maps Digital data GPS GIS Data Capturing data
CES – VCU April 2005 Vector formatsVector formats –Discrete representations of reality Raster formatsRaster formats –Use square cells to model reality X,YX,Y X,Y X,Y Reality (A highway) X,Y Rows Columns Storing data
CES – VCU April 2005 Which parcels are within 50 feet of the road? Well type Drilled Building owner Smith Soil type Sandy ProximityProximity OverlayOverlay NetworkNetworkAnalysis
CES – VCU April 2005 Document Image OutputInternet Paper map GIS Data
CES – VCU April 2005 A GIS works with thematic layers of spatial dataA GIS works with thematic layers of spatial data Answer questions by comparing different layers of dataAnswer questions by comparing different layers of data
CES – VCU April 2005 Representing features in vector data Real-world entities are abstracted into three basic shapesReal-world entities are abstracted into three basic shapes Lines/Arcs/Routes(Streets)Areas/Polygons/Regions (Land uses) Points (Retail stores)
CES – VCU April 2005 Map scale city Map scale determines the size and shape of featuresMap scale determines the size and shape of features Large scaleLarge scale Small scaleSmall scale 1:500 1: : :24000
CES – VCU April 2005 Components of geographic data Three general components to geographic informationThree general components to geographic informationAttributes Geometry Streets BehaviorRules Streets and highways may not intersect
CES – VCU April 2005 Using spatial relationships I-80 connects San Francisco and New York San Francisco is contained by California I-80 has length and direction New York is adjacent to the Atlantic Ocean
CES – VCU April 2005 Overview of ArcGIS ArcInfo ArcEditor ArcView ArcIMS ArcSDE Enterprise Database ArcGIS services Data repository ArcGIS products Increasing functionality from ArcView to ArcInfoIncreasing functionality from ArcView to ArcInfo
CES – VCU April 2005 Spatial data formats ArcGIS can work with spatial data in multiple formatsArcGIS can work with spatial data in multiple formatsCAD Coverage Geodatabase Shapefile RasterTables ArcGIS Internet Map Service
CES – VCU April 2005 Overview of applications All ArcGIS products share common applicationsAll ArcGIS products share common applications ArcMap, ArcCatalog, ArcToolboxArcMap, ArcCatalog, ArcToolbox
CES – VCU April 2005 ArcCatalog A window into your databaseA window into your database Browse your dataBrowse your data Manage your dataManage your data Create and view data documentation (metadata)Create and view data documentation (metadata)
CES – VCU April 2005 ArcMap Primary display applicationPrimary display application Perform map-based tasksPerform map-based tasks –Displaying –Editing –Querying –Analyzing –Charting –Reporting
CES – VCU April 2005 ArcToolbox Geographic processing functionsGeographic processing functions –Data management, analysis, and conversion –Tools vary between ArcGIS products
CES – VCU April 2005 Getting help Contents tab Index tab Search tab Other help –What’s this? –Tool tips