18-Geom-A7 Geospatial Information Systems · December 2018
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. National Exams, December 2018 — 04-Geom-A7, Geospatial Information Systems. Closed book (one approved Casio or Sharp calculator permitted); duration 3 hours. Fifteen (15) questions are provided and any ten (10) constitute a complete paper; each question is of equal value (10 marks), so a complete paper totals 100 marks. Most answers are essay-format; clarity and organization count. All fifteen questions are solved below for completeness.
Longley, Goodchild, Maguire & Rhind, Geographic Information Systems and Science (4th ed.); P. Bolstad, GIS Fundamentals (5th ed.); Worboys & Duckham, GIS: A Computing Perspective (2nd ed.); Burrough, McDonnell & Lloyd, Principles of Geographical Information Systems (3rd ed.); de Smith, Goodchild & Longley, Geospatial Analysis; OGC Simple Feature Access (ISO 19125); ISO 19157 Geographic information — Data quality; ISO 19115 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.
The distinction is fundamentally about where the data and processing reside — on the server or on the client. In a thin-client design the browser is little more than a display terminal: nearly all work — data storage, querying, geoprocessing and often map rendering — is done on the server, which returns finished products such as pre-rendered map tiles or small result fragments. Its advantages are a lightweight client that runs on almost any device with minimal requirements, easy central maintenance and updates (fix once on the server), secure data that never leave the server, and consistent behaviour across users. Its limitations are heavy server load and bandwidth per request, higher latency (a round-trip for each interaction), and limited interactivity or offline capability.
In a thick-client (fat-client) design, data and functionality are pushed out to the client: vector data, cartographic styling and even analysis run in the browser or app (modern JavaScript mapping libraries, WebGL), and the server mainly supplies raw data. Its advantages are rich, responsive interactivity, client-side rendering and analysis, reduced per-interaction server load, and possible offline use. Its limitations are larger downloads and higher client hardware demands, harder deployment and version control across many heterogeneous devices, and greater exposure of data on the client (a security concern for sensitive layers). In practice most modern web-mapping applications are a hybrid: tiled or served base data (thin) combined with client-side rendering and interaction (thick), balancing responsiveness against server cost, data security and the range of user devices. The right split depends on audience devices, data sensitivity, and how interactive the application must be.
