An overview of land records
This topic applies to ArcGIS for Desktop Standard and ArcGIS for Desktop Advanced only.
Land records are composed of all the documents, maps, and information that define the rights and interests in land. Land records can be split into two components:
- A survey or cadastre component, which defines the boundaries splitting up the land (for example, a survey plan)
- A registry component, which describes the corresponding ownership rights, land use, zoning, and so on (for example, a title deed)
When surveying new parcels of land or resurveying existing parcels of land, surveyors must be aware of the legal ownership rights on the land, ownership disputes or conflicts, and historic surveys. Cadastral parcels should be maintained together with both their survey source information (plans) and corresponding registry information (owners).
Boundary network
A parcel of land is defined by a series of straight or curved lines that connect to form a polygon. Each line represents an individual boundary of a parcel and has dimensions that have been derived from measurements taken by a surveyor in the field. In a cadastral survey, surveyors capture or record parcels of land by performing a series of observations or measurements around the parcel boundary. Parcels share common boundaries and corner points to form a network of boundaries and points.
Plans
Surveyors prepare legal documents to reflect the findings of their fieldwork. In the United States, these documents are referred to as plans or plats. There are different types of survey plans depending on the type of survey being performed, for example, subdivision plans, site plans, and topographic survey plans.
Plans contain legal descriptions of the surveyed parcels. Legal descriptions convey instructions on how to locate, in the field, the physical corners that define the parcel boundaries. A legal description describes a parcel of land in a way that is unique and unambiguous. Legal descriptions can vary by type, with the two most common types of legal descriptions being
- A legal description by area reference, for example, "Lot 3, Block 6 of the Hillside Subdivision in San Bernardino County"
- A legal description by perimeter description, for example, a metes (bearings and distances) and bounds (physical monuments) description: "Commencing at the point of beginning then North 45° East 320.00 feet then Northwest 26 ° 200.00 feet"
Land registry
A land registry stores land records that describe information about the following aspects of parcels of land:
- Ownership
- Interests and rights, for example, mining rights
- Site address, both physical and mailing
- Tax value or assessment
- Land-use and zoning
Ownership records are known as deeds and contain information on the owner's name and what rights the owner has to the land parcel. Address records store the site address of the parcel of land and include information about the structures or improvements on the parcel of land. Tax value and assessment/appraisal records contain information about the appraised value of the land. The appraisal also includes the value of the buildings or improvements on the parcel of land. Land-use and zoning records describe what the parcel of land can be used for such as commercial or residential use.
Coordinate-based cadastres
Traditionally, surveyors recorded parcel boundaries by the use of bearings and distance dimensions. With the advent of high-accuracy Global Positioning System (GPS) technology, it has become significantly easier to use coordinates to define the location of parcels. Accurate coordinates give the closest estimate of the true location of a point on the ground and also have error information indicating the reliability of the coordinates. In a coordinate-based cadastre, parcel boundaries are defined by coordinates at each parcel corner in addition to, or instead of, bearings and distances.
Traditional survey methods used for relocating property boundary corners may be interpreted in different ways. When different surveyors use different data to reestablish the location of a boundary, boundary location disputes can arise. A coordinate provides a unique and unambiguous record of a point and can be quickly and accurately relocated with the use of GPS. To gain maximum benefit from the use of coordinates, a system needs to be in place within the cadastre that provides a measure of the reliability and accuracy of coordinates in a parcel boundary network. The more accurate and reliable the coordinate, the higher its weight and influence would be in determining the location of the boundary in the network.