Topographic Map Model
How to Use the Topographic Model
The topographic map model allows students to easily visualize how contour lines can represent the relief of a landscape by means of contour lines. The model consists of an island and several Plexiglas sheets which have been cut to represent progressive changes in a shoreline as sea level is raised. In such a situation, each new shoreline would form a contour line that would close upon itself. The present shoreline is considered to represent the zero foot elevation contour line. The border of the sheet and the present shoreline of the island can be traced onto the blackboard.
Raising sea level will produce a new shoreline that can be shown by fitting the new sheet within the sheet border that is drawn on the blackboard, and then tracing the new shoreline
This process is repeated for each additional contour line.
How to Construct the Topographic Map Model
The model is made by drawing the desired pattern of topographic contours and transferring each line onto a separate sheet flat sheet of Plexiglas or other suitable material. The dimensions of all sheets should be identical. The area enclosed by the contour line is then cut from each sheet with a saw. The sheets are stacked on a thick wooden base, using blocks of wood as spacers. A wire frame is then constructed to fit the space formed within the sheet stack.
The wire form will then approximate the desired shape of the island.
The form is covered by paper strips which have been soaked in a glue/water solution.
After it is allowed to dry, the surface of paper strips is covered by a layer of papier-mache, which can be obtained commercially. The fine texture of papier-mache allows the surface of the model to be built up so it matches almost exactly the form made by the cut-out sheets. After again drying, the final form is painted. When in use, the model will provide all the support needed by the Plexiglas sheets.