18-Geom-A7 Geospatial Information Systems · May 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams — May 2014 — 04-Geom-A7 Geospatial Information Systems. Closed-book; no calculator permitted. Format: twenty-three short-answer questions of equal value (5 marks each); a candidate answers any twenty, but all twenty-three are solved in full below. Datum and coordinate conventions follow the Canadian spatial reference framework — NAD83(CSRS) horizontally and CGVD2013 vertically.
Reference texts: P. A. Longley, M. F. Goodchild, D. J. Maguire & D. W. Rhind, Geographic Information Systems and Science (4th ed., Wiley, 2015); P. Bolstad, GIS Fundamentals: A First Text on Geographic Information Systems (6th ed., XanEdu, 2019); P. A. Burrough, R. A. McDonnell & C. D. Lloyd, Principles of Geographical Information Systems (3rd ed., Oxford, 2015); M. Worboys & M. Duckham, GIS: A Computing Perspective (2nd ed., CRC, 2004); ISO 19115 Geographic information — Metadata.
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.
Metadata is "data about data" — structured, standardized documentation that describes the content, quality, condition, lineage and context of a geospatial dataset without containing the mapped features themselves. It answers the who, what, when, where, why and how of a dataset so that a user who did not create it can judge whether it is fit for a given purpose and can use it correctly. In Canada and internationally, GIS metadata is normally recorded to the ISO 19115 standard (encoded in XML through ISO 19139), which groups the documentation into identification, data-quality, spatial-reference, distribution and lineage sections. Typical examples in a GIS include: the coordinate reference system, datum and map projection (e.g., NAD83(CSRS), UTM Zone 10N); the source scale or raster resolution; the date of capture and the update/currency cycle; positional and attribute accuracy statements; the lineage or provenance (how the layer was produced and from what source); attribute (field) definitions and coded-value domains; the data custodian, contact and access/licensing constraints; and the geographic extent (bounding coordinates). Without metadata a layer's coordinates and attributes are essentially untrustworthy, because their reliability and meaning are undocumented.
