Tuesday, June 12, 2012

Mapwork in the exam

Working through old IEB exam papers it becomes clear that certain questions always appear in the mapwork question papers. The 1:50 000 range topographic maps are used in the exams and the projection used to create these maps is the Gauss Conform Projection. Also indicated on the topographic map is
the central meridian used for this projection.

Distance, gradient and time calculations are always asked. Expect to get a'magnetic bearing' calculation!
Make sure you know how altitude is indicated on a topographic map – contour lines (with a contour interval of 20m), spotheights, trigonometry beacons and benchmarks. You will need this in order to calculate the gradient, to spot the highest point on the map and to describe the general gradient or elevation of an area.

The scale of the orthophoto map is five times smaller than that of the topographic map. A scale of 1:10 000 is a large scale and 1:50 000 is a small scale.

Formal cross-sections are usually to time consuming and rarely asks, however, sketch cross-sections are asked often. A sketch cross-section (free hand) is a sketch of what you see on a photo and not a precise graph.

Settlement questions are very common with questions about the type of rural settlements (isolated or nucleated) and farming activity (intensive or extensive). Land use zones must be identified such as CBD, rural-urban fringe, industrial area and their positions explained.

With GIS you will have to suggest themes (layers) that you would use in a presentation about a specific area. It is very important that you know the relevant concepts for GIS!