About loading data to a parcel fabric

This topic applies to ArcGIS for Desktop Standard and ArcGIS for Desktop Advanced only.

The parcel fabric relies on topological correctness when representing and storing parcel data. Existing parcel datasets being migrated into the parcel fabric need to reflect a similar level of topological correctness.

The Load A Topology To A Parcel Fabric geoprocessing tool is used to load a topologically clean, validated topology of parcel feature class data to the parcel fabric. A geodatabase topology is created in a feature dataset containing a feature class of parcel lines, a feature class of parcel polygons, and, optionally, a feature class of points (parcel corners). The topology is validated against a required set of rules, and once the topology is clean, it is loaded to the parcel fabric using the geoprocessing tool.

Topology rules

When a topology is validated, features participating in the topology are validated against a set of defined rules, and violations of the rules are treated as errors. When using the Load A Topology To A Parcel Fabric geoprocessing tool, the following set of topology rules is required:

  1. [Line feature class] Must Be Covered By Boundary Of [Polygon feature class].
  2. [Line feature class] Must Not Self-Overlap.
  3. [Line feature class] Must Not Self-Intersect.
  4. [Line feature class] Must Be Single Part.
  5. [Line feature class] Must Not Intersect Or Touch Interior.
  6. [Polygon feature class] Boundary Must Be Covered By [Line feature class].

The [Line feature class] Must Be Covered By Boundary Of [Polygon feature class] rule can be marked as an exception if the line is being migrated as a connection line or road centerline to the parcel fabric. Connection lines are lines that connect parcel points to control points or lines that connect blocks of parcels. If a line is being migrated as a connection line, there should be a Category field on the source lines attribute table and the category value should be set to 3 (for connection line).

A topology can be validated in ArcCatalog or ArcMap. In ArcCatalog, the entire dataset is validated. In ArcMap, you can choose to validate a subset of the data by using either the Validate Topology In Current Extent Validate Topology In Current Extent or the Validate Topology In Specified Area Validate Topology In Specified Area tool located on the Topology toolbar.

Once a topology is validated, any violations of the topology rules or errors are symbolized and displayed in the topology layer in ArcMap. Topology errors are symbolized by points, lines, and polygons.

Topology layer with errors
Topology layer with errors

Topology errors can also be viewed on the Error Inspector dialog box Error Inspector accessed from the Topology toolbar. Error Inspector lists the topology errors in the current visible extent. You can also choose to list all topology errors. Errors are listed by the rule that was violated.

Topology Error Inspector
Topology Error Inspector

Learn more about the Error Inspector dialog box

Learn more about minimizing topology errors when migrating parcel data to a parcel fabric

Once the validated topology is clean with no errors, it can be loaded to a parcel fabric. The Load A Topology To A Parcel Fabric tool is located in the Catalog window under Toolboxes > System Toolboxes > Parcel Fabric Tools.tbx > Data Migration.

Using the Load A Topology To A Parcel Fabric geoprocessing tool

The Load A Topology To A Parcel Fabric geoprocessing tool can use either the parcel line or parcel polygon feature class as the Input (Topology) Feature Class; however, a topology of both a polygon and line feature class is required for loading to complete successfully.

Load a Topology to a Parcel Fabric dialog box
Load a Topology to a Parcel Fabric dialog box

If there is a selection present on the input polygon or line feature class, only the selected features will be loaded into the fabric.

Migrating point features

Parcel point features can be optionally loaded to the parcel fabric. You would migrate existing point features to the parcel fabric when you need the user-defined attribute values on those points to be reflected in corresponding points in the parcel fabric. As with polygon and line features, if there is a selection on the point feature class layer, only the selected points will be migrated.

Minimum Line String Segment Count

This value is used to control whether or not a multisegmented boundary line is migrated as a natural boundary. Multisegmented lines or polylines are split into individual, two-point lines if the number of segments is less than the specified Minimum Line String Segment Count. If the polyline contains more segments than the specified value, it is migrated as a natural boundary. Natural boundaries follow natural features such as rivers and do not usually have COGO attributes associated with them. Line strings are used to represent natural boundaries in the parcel fabric.

Control Match Tolerance

Use this tolerance to associate points of newly loaded parcels to existing control points in the parcel fabric. Parcel fabric points are associated with existing control points if they lie closer to the control point than the tolerance specified. Use the Import Control Points wizard to load control points to the parcel fabric.

Units

Make sure the units specified for Direction Units, DirectionType, and Area Units match the units ofthe stored COGO values.

Radial Point Tolerance

This tolerance is used to improve topological integrity in data loaded to the parcel fabric. The center points of adjacent curves and overlapping curves will be merged into a single center point if they lie within the tolerance specified.

Accuracy Category for Inversed Lines

Automatically set the accuracy category of lines with COGO dimensions that have been generated from the line geometry during the loading process. Accuracy categories are used by the parcel fabric adjustment. If you do plan to adjust the parcels, it is important to specify accuracy categories for parcels and lines. if no accuracy category is specified, the default category of 4 is used. It is recommended that you set lines with inversed COGO dimensions to a low accuracy category of 6. Inversed COGO dimensions may be inaccurate and unreliable and should not influence the outcome of an adjustment.

Loading data to the parcel fabric Local Government Information Model

The parcel fabric can be enabled with the Local Government Information Model. When the Local Government Information Model is enabled on a parcel fabric, parcel types, attributes, and domains that reflect the editing requirements of Local Government parcel maintenance are added to parcel fabric tables. The parcel fabric layer is displayed and symbolized using the Local Government configuration, and the parcel fabric can be used in efficient and automated parcel editing workflows.

When preparing data for loading to a parcel fabric enabled with the Local Government Information Model, it is recommended that data be formatted and then loaded into a staging geodatabase. In the staging geodatabase, parcel data is separated by type and topologies are created for each parcel type. Topologies are loaded into the parcel fabric from the staging geodatabase using the Load A Topology To A Parcel Fabric geoprocessing tool.

See the load parcel polygons workflow to load parcel polygons in the form of shapefiles or CAD files into the parcel fabric Local Government Information Model.

See the load parcels with COGO dimensions workflow to load parcel lines with COGO dimensions to the parcel fabric Local Government Information Model.

More information

See Data loading considerations for more information about loading attribute fields, plans, and dealing with overlapping parcel data.

For more information about loading large parcel datasets, see Loading large datasets.

For more information about loading right-of-ways and road centerlines, see Loading right-of-ways.

Related Topics

5/12/2014