What is parcel editing?
This topic applies to ArcEditor and ArcInfo only.
Parcel editing involves working with and updating land parcel boundaries, land records, and utility features. When editing parcels, you are working with polygon features, which represent the parcel, line features, which represent the parcel boundary and point features, which store coordinates for the parcel corners. Many utilities such as roads, pipeline networks and wastewater networks are defined in relation to the parcel boundary and are thus dependent on the parcel boundary. If parcel boundaries are updated, dependent utilities should be updated as well.
The parcel editing environment in ArcGIS 10 provides an intelligent editing environment that is tailored specifically for working with land parcels.
The parcel editing environment works with a parcel fabric dataset. A parcel fabric dataset is created as a new node under a feature dataset in the Catalog window. The parcel fabric dataset is a set of polygons or land parcels that are defined by a network of connected parcel lines. Connection lines and radial lines connect islolated groups of parcels to ensure a seemless boundary network.
Parcels in the parcel fabric are defined by points and lines as well as polygons. Lines store the dimensions of the parcel boundaries and points coordinate (x, y) the parcel on the ground. Parcel corner points are coincident with the ends of parcel lines and are common between adjacent parcels. Each parcel has its own set of lines, which means that neighboring parcels will each have their own line to represent the common boundary. The common boundary has two end points, and multiple lines connect between the same two points.
Lines can be boundary lines (the boundary of the polygon) as well as connection lines, radial lines, and so on.
Methods of creating parcels
The parcel fabric editing environment provides a comprehensive and flexible set of parcel editing tools. Parcel editing is efficient and simple. Editing workflows are designed for working with different types of parcels such as tax parcels, easement parcels, subdivision blocks, and so on.
Parcels in the parcel fabric can be created using the following methods:
Parcel boundary dimensions are entered or digitized in a sequenced loop. Lines can also be created using COGO tools.
Parcels are created from linework entered in the parcel construction environment. Linework can be traversed in, pasted in, and created using COGO tools.
Parcels are created from the division of an existing parcel. The parcel division tool can be used to divide existing parcels into equal areas, into in equal widths or by proportional areas. Existing parcels can also be split using construction line work using the Construct from parent tool.
Adjacent parcels are merged to create new parcels. The original parcels remain as historic parcels.
If a new parcel is added to overlay an existing parcel, a remainder parcel can be created from the existing underlying parcel.
Spatial accuracy and parcel fabric adjustment
Corner points in the parcel fabric store x, y, z coordinates, which spatially locate parcels on the ground. These corner point positions are updated by processing parcel line data in a fabric adjustment process. The process requires survey control points, which are also stored in the fabric. Control points define and publish accurate, surveyed coordinates for physical features on the surface of the earth. When parcel lines are processed with survey control points in a fabric adjustment process, the result is more accurate parcel corner positions (x, y, z coordinates).
Parcel corner changes (coordinate changes) are stored and subsequently used to update other layers, thereby maintaining spatial coincidence with the parcel fabric base-map. This process is called feature adjustment; it is a distinct and separate task from the parcel fabric adjustment, since it adjusts features that are not part of the parcel fabric dataset, but that are associated with the fabric.
Adjustment of dependent features
Coordinate changes in parcel corner points resulting from fabric adjustments are stored as vectors and subsequently used to update features that are dependent on parcel boundaries such as sewer and water lines. Spatial coincidence of dependent features can be maintained with the parcel fabric basemap. This process is called feature adjustment; it is a distinct and separate task from the parcel fabric adjustment, since it adjusts features that are not part of the parcel fabric dataset, but that are associated with the fabric.