18-Geom-A6 Cadastral Studies · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — December 2014 — 04-Geom-A6 Cadastral Studies. Closed-book; no calculator permitted. Format: five questions of equal value (25% each); any four constitute a complete paper, and all answers are required in essay format. All five questions are solved in full below. Legal and land-registration content is framed in the Canadian context (common-law standard of care; provincial Torrens / registry systems; Canadian cadastral institutions).
Reference texts: Survey Law in Canada (Canadian Council of Land Surveyors / Carswell, 1989); Brown, Robillard & Wilson, Brown's Boundary Control and Legal Principles (7th ed., Wiley, 2017); G. Larsson, Land Registration and Cadastral Systems (Longman Scientific & Technical, 1991); ISO 19152 Land Administration Domain Model (LADM) and FIG Statement on the Cadastre; H. Demsetz, "Toward a Theory of Property Rights," Am. Econ. Rev. 57 (1967); G. Hardin, "The Tragedy of the Commons," Science 162 (1968).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
All three terms describe interconnected networks (that is the sense of "fabric") that make up a modern digital cadastre, but they operate at different layers — the measurements, the ownership polygons, and the legal lines. They are related and partly overlapping, yet not identical.
Survey fabric is the network of survey measurements and control that underlies everything else: the bearings, distances, angles, coordinates, and monument positions recorded in successive plans of survey, tied together through common points. It is the geometric/observational framework — the raw and adjusted measurements, ideally carried in a least-squares-adjustable connected network so that new survey observations can be integrated and the whole strengthened over time. The survey fabric is about how accurately points are measured and connected, and it captures measurement quality, redundancy, and provenance.
Parcel fabric is the seamless, topologically-integrated map of ownership parcels — the continuous surface of connected parcel polygons (with their boundary lines, connection lines, and corner points) covering an area with no gaps or overlaps. In modern GIS practice (for example the parcel-fabric data model), the parcels are not independent floating polygons but a single connected dataset built on top of the survey fabric: the recorded measurements are used to place and adjust the parcels, and editing one parcel updates its neighbours because they share geometry. The parcel fabric is about the integrated spatial representation of who owns what, as a continuous map.
Boundary fabric is the network of the legal boundaries themselves — the interpreted lines that define the extent of the property rights, together with their supporting evidence and legal status. It is the layer at which the surveyor's professional opinion and the law live: a boundary line is not merely a geometric edge (survey fabric) or a polygon side (parcel fabric) but the legally-recognised limit of an estate, which may be a general (approximate) boundary or a precisely-fixed one, and which may or may not coincide exactly with the measured geometry.
The differences. The survey fabric is a measurement framework (accuracy, control, observations); the boundary fabric is a legal-rights framework (the lawful limits of ownership and the evidence for them); and the parcel fabric is the integrated map product that binds the two by using the measurements to portray the boundaries as a continuous set of ownership polygons. In an ideal cadastre they nest together — the survey fabric supplies the geometry, the boundary fabric supplies the legal meaning, and the parcel fabric is the seamless spatial database that carries both — but they remain conceptually distinct, and a defect in one (e.g. a measurement error in the survey fabric, or an unresolved legal dispute in the boundary fabric) does not automatically correspond to a defect in the others.
