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.
A GIS is usually described by five core functional groups that follow the flow of data through the system. (1) Data input/capture — acquiring spatial and attribute data by digitizing, scanning, surveying/GNSS, photogrammetry, remote sensing and importing existing datasets, including georeferencing and edge-matching. (2) Data storage and management — organizing the data in a spatial database (geodatabase) so it can be efficiently stored, indexed, edited by multiple users, and kept internally consistent through topology and integrity rules. (3) Data manipulation and transformation — coordinate transformations and re-projection, format and structure conversion (e.g., raster–vector), reclassification, generalization and conflation to bring layers into a common framework. (4) Query and analysis — the analytic heart of a GIS: attribute and spatial query, overlay, buffering and proximity analysis, network analysis, surface/terrain analysis and spatial statistics that turn data into new information. (5) Data output and visualization — presenting results as maps, charts, reports, tables and, increasingly, interactive web services. These functions are often summarised as capture → store → manage → analyse → display, and it is the query-and-analysis stage that distinguishes a GIS from a mere mapping or drafting tool.
