Checking the topological integrity of the parcel fabric

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

The Check Parcel Fabric command is available for validating the topological integrity of your parcel fabric. The command identifies data corruptions such as out-of-sequence parcel traverse lines, parcels that are not closed, invalid dimensions and so on.

The command is run on a parcel fabric in the Catalog window. To run the command, right-click a parcel fabric in the Catalog window and click Check Parcel Fabric.

Check Parcel Fabric command
Check Parcel Fabric command

Checking the fabric is useful for validating parcel data that has been migrated to the fabric from standard feature classes or CAD files. When migrating data into the fabric, inconsistencies and errors in the source data can result in corruptions in the fabric. The command identifies data corruptions in the fabric and reports the errors in a list format that can be saved for future use.

Parcel errors
Parcel errors

Errors found in parcels, lines, and points are listed with the ObjectID of the corrupt feature. The ObjectID can then be used to locate the corresponding feature in the parcel fabric. The corrupt feature can be either edited and corrected or unjoined and deleted.

Parcel fabric validation errors

The Check Parcel Fabric command will identify and report the following data corruption errors:

Parcel errors

Line sequence error

The parcel contains lines that are out of sequence.

In this case, the parcel's traverse lines are out of sequence, for example, 1-2-4-3. Line sequence errors are caused either by incorrect data entry of the parcel traverse or by dangling, overshot/undershot, or tiny line segments in migrated data. For example, in the parcel line feature class shown below, an undershot line is resulting in a failure by the importer to create a fabric parcel:

Dangling line
Dangling line

Often, the corrupt parcel is not rendered in the fabric. To open and examine the parcel, the parcel must be selected in the parcel layer's attribute table and opened by right-clicking the parcel, which is listed in the Parcel Explorer dialog box.

Line sequences do not start at 1

The sequence IDs of the lines within this parcel do not start at 1. Parcel traverse lines are stored in the Lines table, and the sequence of the traverse lines should always start at 1.

Traverse line sequence

Causes

  • Road centerline parcels with multiple paths

    Each path should be a separate parcel and not form one single parcel.

  • Connection line as the first line of the parcel

    The line category should be changed to Origin Connection rather than Connection.

  • Incorrect from- and to-point IDs in the traverse grid

    Sometimes this is caused by incorrect data entry when entering a parcel in a parcel group.

Often, the corrupt parcel is not rendered in the fabric. To open and examine the parcel, the parcel must be selected in the parcel layer's attribute table and opened by right-clicking the parcel, which is listed in the Parcel Explorer dialog box.

Parcel has dangling boundary links

This error can result from a parcel traverse that does not close back onto its starting point.

Parcel lines do not form a closed loop
Parcel lines do not form a closed loop.

Parcel lines do not form a closed loop

Causes

  • Dangling or overshot lines in migrated data, which has resulted in incorrectly assigned from- and to-points
  • Overlapping lines in migrated data, which has resulted in a duplicate parcel line in the parcel fabric

Parcel has disconnected links

A disconnected link is a line that is not connected to or part of a parcel boundary but is stored as a parcel traverse line for that parcel boundary. This line could be connected to another parcel boundary in the fabric but is related to the wrong parcel.

Possible causes

  • Incorrect data entry or migration of poor-quality parcel data
  • Data corruption resulting from manually editing parcel fabric system tables

Parcel has missing points

This parcel's boundary lines are referencing point IDs that do not exist.

Possible causes

  • Data corruption resulting from manually editing parcel fabric system tables
  • Migration of poor-quality parcel data

Parcel contains lines with errors

There are errors on some of the traverse lines of this parcel. A list of line errors should appear with the parcel error. Examples of line errors are invalid line categories and invalid line radii. See the 'Line errors' section for a more detailed explanation of each type of line error.

Parcel contains line points with errors

There are errors on some of this parcel's points that are line points on other parcels. A list of line point errors should appear with the parcel error. Examples of line point errors are invalid referenced point IDs—for example, the line point refers to a point on the parcel that does not exist—and invalid referenced lines. See the 'Line point errors' section for a more detailed explanation of each type of line point error.

Parcel contains points with errors

There are errors on some of this parcel's points. A list of point errors should appear with this parcel error. Examples of point errors are invalid coordinates and invalid curve center points. See the 'Point errors' section for a more detailed explanation of each type of line point error.

Parcel does not have valid shape

The parcel does not have a valid, geometric shape; for example, the parcel shape is self-intersecting or the parcel has no geometric shape (the shape is null).

Line errors

Line has invalid ID

The ObjectID of this line is not valid.

Line has invalid sequence

The sequence value for this line (in the Sequence attribute field in the parcel lines table) is not a valid number.

Line has invalid category

The category value for this line ( in the Category attribute field) is not a recognized value. The following line categories are recognized:

  • 0—Boundary line
  • 1—Dependent line
  • 2—Precise connection line
  • 3—Connection line
  • 4—Radial line
  • 5—Road frontage line
  • 6—Origin connection line
  • 7—Part connection line

Line has invalid from point

The parcel line is referencing an invalid from-point ID. The referenced point ID most likely does not exist in the points table.

Line has invalid to point

The parcel line is referencing an invalid to-point ID. The referenced point ID most likely does not exist in the points table.

Line has invalid center point

The center point for this curved line is invalid. The referenced point ID most likely does not exist in the points table.

Line has invalid radius

The value stored in the Radius attribute field for the curved line is invalid. The radius value is most likely missing.

Line does not have a valid shape

The line shape geometry is invalid. The line shape could be corrupt or missing.

Line has same from and to points

This line is referencing the same from- and to-point IDs. The same from- and to-point IDs can be seen in both the parcel traverse dialog box and in the FromPointID and ToPointID attribute fields in the Lines table.

Causes

  • Incorrect data entry of the parcel traverse
  • Overlapping lines of different lengths in data that has been migrated to the parcel fabric

    In the graphic below, there are two overlapping lines for the same parcel boundary that partially overlap each other:

Overlapping parcel lines
Overlapping parcel lines
Run a topology to find overlapping lines in your source lines before building a fabric source for migration into the parcel fabric.

Curve is missing a radial line

Each curved line in a fabric parcel has two stored radial lines in the lines table. This error is generated when a curve has one or both radial lines missing.

Radial lines

Causes

  • Incorrectly stored and entered multiring or donut parcels
  • Poor-quality data that has been migrated to the parcel fabric

Other lines in this parcel boundary have the same from PointID or Other lines in this parcel boundary have the same to PointID

Causes:

  • The to and from points of the line have been reversed. This could occur when a traverse line is out of sequence.
  • A point in the parcel connects more than two boundary lines. This could occur when a connection line has been incorrectly categorized as a boundary line.

Point errors

Invalid coordinate

One or all of the x,y,z coordinate values of the parcel point are invalid. A coordinate might be missing or might contain an invalid number or character.

The center point attribute is set incorrectly

If a point is the center point of a curve, it is flagged with a value of 1 in the CenterPoint attribute field in the Points table. This error occurs when a point is not the center point of a curve and has a CenterPoint attribute value of 1.

Point is missing

A point is being referenced that most likely does not exist in the Points table. For example, this error will occur if a line references a from- or to-point that does not exist in the Points table.

Point does not have a valid shape

The point shape geometry is invalid. The point shape could be corrupt or missing.

Line point errors

Linepoint does not refer to a valid point

A parcel point becomes a line point when it lies on an adjacent parcel boundary but does not split the boundary. In the LinePoints table, LinePointID references a point ID in the Points table. This error will occur when the LinePointID attribute value is not a valid point ID. The point ID most likely is missing.

Line points table

Linepoint does not have a valid from point

The point ID referenced in the FromPointID field is not a valid point ID. The point ID is most likely missing.

Linepoint does not have a valid to point

The point ID referenced in the ToPointID field is not a valid point ID. The point ID is most likely missing.

Linepoint does not have a valid line

This error occurs when a line does not exist between the from- and to-point IDs (FromPointID, ToPointID) referenced in the LinePoints table.

Control point errors

Control point has invalid coordinates

One or all of the x,y,z coordinate values of the control point are invalid. A coordinate might be missing or might contain an invalid number or character.

Control point back reference is invalid

A control point references the fabric point to which it is associated via the PointID field in the Control table. The fabric point stores a back reference to the control point via the Name field in the Points table. This error indicates that the ID references in the Points or Control table are either incorrect or missing.

Control and Points tables
Control and Points tables

1/25/2013