Contour maps
can be used to chart anything from high and low air-pressure patterns to oil-well depths. Most commonly they record changes of elevation (topography) in a geographic area. Each contour line on a topographical map represents a single elevation, and the difference in elevation between each line on the map is always the same. On a steep hill or cliff, the lines are very close together. They are farther apart on a gradual slope. Contour lines never cross. Contour maps enable you to create an accurate picture of any type of terrain quickly and easily.
Instructions
1. Using your sample map, photo and elevation data, or your imagination as a guide, mark each elevation point as a dot and write the elevation beneath it. If the area you're mapping includes streams, ponds, shoreline, or roads, you can draw them in lightly.
2. Choose the difference in elevation between your contour lines. If the map area includes steep hills, you may want each line to represent a 100- or 200-foot change in elevation. If it depicts a gentle, rolling countryside, a 10- or 20-foot interval will probably work better.
3. Starting with the highest elevations first, use your pencil to connect all the dots that represent equal elevations. Make sure that each line stays on the high side of any dot that marks a lower elevation. Check for mistakes or messy spots and clean them up.
4. Trace over your pencil lines with your pen to make nice bold contour lines. Mark each contour line just once with its elevation and erase all of the penciled elevation numbers.
5. (Optional) Use green highlighter to designate areas of higher elevation.
Tags: each line, contour line, Contour maps, difference elevation, difference elevation between, elevation between
