Models and Structures of ArcGIS
UML and Data Modeling
ElementsLongley et al., 8 (2/e) Zeiler, chs. 4, 5, and 12
Review Zeiler ch. 1
Models for GIS
• representation of reality --> model
• GIS itself is based on a model of complexity
• GIS is used to model complexity• full representation of reality?• data model = limited representation of reality– a discretization or partitioning of space– finite, discrete nature of computing devices
Data Model
• representation of information about the process
• FIELD … “grid”• OBJECT … “isoline”• FIELD or OBJECT … “geo-relational”
• “Delauney triangulation” (alternative)
3 Data Models
• geo-relational coverage (object view; from classic ArcInfo)
• geo-relational shapefile (object view; from ArcView)
• geodatabase (object-oriented; new in ArcGIS)
A
B
command line interfaceUnix, NT, WindowsArcView as interface
Georelational Data Model:“Classic” ArcInfo and ArcView
ArcInfo Coverage as a Data Structure
Image courtesy of Louisville/Jefferson County Information Consortium, Kentucky
Data Structure• not tied to process at all• concerned simply with what can be computed and what can’t
• the way in which the data model is represented in the GIS– DEM for field model– contour for isoline model (variation on object)
– TIN for Delauney triangulation model– coverages, shapefiles for geo-relational– geodatabase for OO geodatabase
Data Structures
• ArcInfo coverages• ArcView shapefiles• ArcInfo grids, USGS DEMs • Images (e.g., georeferenced tiffs)
• TINs• Geodatabases
ArcGIS 9 Icons( Zeiler, pp. 65-71 )
yellow coverage
gray geodatabase
green shapefile
Geodatabase
If coverages are apples …and shapefiles are oranges …The Geodatabase can be your grocery bag…
Elements of the Geodatabase
• Feature Datasets• Feature Classes• Relationship classes• Geometric Networks• Domains• Ranges• Coded Values• Topology• Tables• Metadata• And More!!!
Geodatabase
• Features and attributes as objects
• Relationships among features
• Validation or editing rules, behaviors
• “Container” for– Vector, raster, tabular data
– Relationships– Topology
MS-Office
Object Table
Relationships for a feature
ESRI Data Models for Geodatabase Templates
Pre-designed schema (skeleton) of
• Objects-Feature classes-Tables
• Relationships• Domains• Rules
Why Data Models & Gdb Templates?
• Work with users & partners on practical design projects
• Build useful ready to load geodatabases
• Continue the process with feedback from real projects
• Support & encourage standards
ArcGIS Data ModelsAdministrative BoundariesAgricultureBasemapBiodiversity/ConservationCadastre 2014Defense/IntelEnergy UtilitiesEnvironmental Regulated FacilitiesHistoric PreservationHydrographic/Navigation (IHO)
Local GovernmentMarinePetroleumPipelineSystem ArchitectureTelecommunicationsTransportationWater UtilitiesWater Resources (Hydro, Groundwater)ForestryGeologyLand Parcels
http://support.esri.com/datamodels
Arc Marine dusk.geo.orst.edu/djl/arcgis