Post on 26-Dec-2015
Parcel Data Models for Parcel Data Models for the Geodatabasethe Geodatabase
Indiana GIS Conference 2012
WelcomeWelcome
Joyce WestGIS Account ManagerThe Sidwell Company
Presentation AgendaPresentation Agenda
Parcel-based GIS editing to maintain common boundaries with:◦Polygon Model◦Coincident Boundary Model◦Parcel Fabric Model
Some backgroundSome background
Coverage Format◦Legacy Esri format◦Contain features organized into feature classes-
arc, node, label point, polygon, and annotation◦Support shared geometry and polygon
adjacency◦Maintain topology
Some backgroundSome background
Shapefile format◦Supports simple point, line, area features◦Non-topological geometry◦Attributes have one-to-one relationship with
shapes◦Common for data sharing
Some backgroundSome background
Geodatabase format◦Data storage and management◦Uses standard RDBMS products
MS Access MS SQL Server Oracle
◦Map graphics and attributes stored together◦Supports relationships and business rules◦Supports multi-user access and editing
Geodatabase EditingGeodatabase Editing
Appropriate software to support◦Advanced Cartography ◦Coordinate Geometry◦Create and edit feature relationships
i.e. feature linked annotation◦Topology rules and fix operations◦Multi-user editing◦Distributed geodatabases
Polygon ModelPolygon Model
The polygon model is a simple, straightforward GIS data model where map features exist as separate polygons or data layers.
Polygon ModelPolygon Model
Store map features as separate polygons such as parcels, subdivisions, corporate limits
Edit lines or edit polygons directlyMay use cut and paste operationsPlacement of edits is user-controlledUse map topology tools to maintain
alignments in personal or file geodatabaseRun topology checks to insure data integrity
Features on top of
features on top of
features
Can result in this…
Coincident Boundary ModelCoincident Boundary Model
The Coincident Boundary Model is based on the concept of using common geography to represent multiple features. To accomplish this, a linear feature class is created in the geodatabase that stores all boundary features.
Common Coincident Common Coincident BoundariesBoundaries
Cadastral/Ownership Parcel Line Lot Line Subdivision Road Right-of-Way City/State/County boundary
EasementsZoningGovt Districts
Tax DistrictsCensus data
Coincident Boundary ModelCoincident Boundary Model
Map features occupy the same place in the same plane
Map features that are common to two or more data layers
User selects which features will participate in this model
Assign multiple feature identities or boundary types
Coincident Boundary ModelCoincident Boundary Model
Establish a hierarchy to symbolize map features
Edit map features as lines, often just by changing a tag
After edits, polygons can easily be updated by querying and extracting lines attributed with the appropriate features from the editable layer
Coincident Boundary ModelCoincident Boundary Model
Coincident Boundary ModelCoincident Boundary Model
The Parcel Fabric ModelThe Parcel Fabric Model
The Parcel Fabric is a data model and geodatabase maintenance environment developed by Esri. The Parcel Fabric is a modeling solution that stores cadastral information as a continuous surface of connected parcels.
What is The Parcel Fabric?What is The Parcel Fabric?
• A specialized grouping of core Arc feature classes• Control points• Line points• Points• Lines• Polygons (Parcel, Lot, etc…)
• Detailed Relationships are tracked between them
Fabric Sub LayersFabric Sub Layers
Control Points ◦Used to run the Least
Squares AdjustmentLine Points
◦Track intersections from adjacent parcels that don’t require a “Node” pointPoints
◦Track “Node” points for a given parcel◦Often called “Parcel Points”
Fabric Sub LayersFabric Sub LayersLines
◦Boundary lines of Fabric polygons
◦Can be categorized to track additional line types
Fabric RelationshipsFabric Relationships
Lines to Points◦Every Fabric line know it’s “from” and
“to” Fabric point
Lines for every boundary◦Every Fabric line knows the parcel
polygon it defines the boundary of
Fabric Sub LayersFabric Sub LayersParcels
◦Parcel Polygon◦Can be categorized to
track multiple polygon types
Results in overlapping geometry
Data Integrity and Data Integrity and RedundancyRedundancy
Topological accuracy is ensured◦Joining parcels with shared points
Each parcel has its own set of lines◦Overlapping for a common boundary◦More lines define relatively fewer points
012 31 32
33 34
9 Points16 Lines
Parcel Fabric EditingParcel Fabric Editing
Parcel editor toolbar in core Editing workflows allow easy input of
fabric featuresSimple merge and split functionsGroups transactions by Plans
Parcel Fabric BenefitsParcel Fabric Benefits
Improves data accuracy ◦least squares adjustments
Adjusts related featuresAutomatically stores historical geometryTopology rules can be established
between features and the fabric
LGIMLGIM
Local Government Information Model◦Organization of data◦Extends use of GIS◦Easy to deploy Maps & Apps
Parcel Fabric Layer
In SummaryIn Summary
Polygon Model ◦ Run topology checks◦ Relies on editor vigilance◦ May take more steps
Coincident Boundary Model◦ One feature – multiple representations◦ Keeps polygon edges aligned◦ Efficient editing
Parcel Fabric Model◦ Interconnected and related point, line and polygon
features◦ Automatically stores history◦ Uses edit wizards and spatial adjustment
Thank youThank youJoyce West
GIS Account ManagerThe Sidwell Company | www.sidwellco.com