1. Parcel Data Models for the Geodatabase
Indiana GIS Conference 2012

2. Welcome
Joyce West GIS Account Manager The Sidwell Company

3. Presentation Agenda
Parcel-based GIS editing to maintain common boundaries with:
Polygon Model
Coincident Boundary Model
Parcel Fabric Model

4. Some 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

5. Some background Shapefile format
Supports simple point, line, area features
Non-topological geometry
Attributes have one-to-one relationship with shapes
Common for data sharing

6. Some 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

7. Geodatabase 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

8. Polygon Model
The polygon model is a simple, straightforward GIS data model where map features exist as separate polygons or data layers.

9. Polygon Model
Store map features as separate polygons such as parcels, subdivisions, corporate limits
Edit lines or edit polygons directly
May use cut and paste operations
Placement of edits is user-controlled
Use map topology tools to maintain alignments in personal or file geodatabase
Run topology checks to insure data integrity

10. Features on top of
features on top of
features
Can result in this…

12. Coincident 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.

13. Common Coincident Boundaries
Cadastral/Ownership
Parcel Line
Lot Line
Subdivision
Road Right-of-Way
City/State/County boundary
Easements
Zoning
Govt Districts
Tax Districts
Census data

14. Coincident 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

15. Coincident 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

16. Coincident Boundary Model

17. Coincident Boundary Model

19. The 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.

20. 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

21. Fabric Sub Layers Control Points Line Points Points
Used to run the Least Squares Adjustment
Line Points
Track intersections from adjacent parcels that don’t require a “Node” point
Points
Track “Node” points for a given parcel
Often called “Parcel Points”

23. Fabric Sub Layers Lines Boundary lines of Fabric polygons
Can be categorized to track additional line types

24. Fabric Relationships Lines to Points Lines for every boundary
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

25. Fabric Sub Layers Parcels Results in overlapping geometry
Parcel Polygon
Can be categorized to track multiple polygon types
Results in overlapping geometry

26. Data Integrity and Redundancy
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
9 Points
16 Lines 33 34

27. Parcel Fabric Editing Parcel editor toolbar in core
Editing workflows allow easy input of fabric features
Simple merge and split functions
Groups transactions by Plans

28. Parcel Fabric Benefits
Improves data accuracy
least squares adjustments
Adjusts related features
Automatically stores historical geometry
Topology rules can be established between features and the fabric

29. LGIM Local Government Information Model Organization of data
Extends use of GIS
Easy to deploy Maps & Apps
Parcel Fabric Layer

30. In Summary Polygon Model Coincident Boundary Model Parcel Fabric 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

31. Joyce West GIS Account Manager The Sidwell Company | www.sidwellco.com
Thank you
Joyce West
GIS Account Manager
The Sidwell Company |