New Geography in Action Junior Cycle Geography Cross-section
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0 0 1 2 : Figure 7.3 Drawing a cross-section
A cross-section is a slice through a particular feature, in this case the landscape. It shows us the slopes and relief features. Hill walkers and mountain climbers often use cross-sections to examine routes.
How to draw a cross-section:
1. Put the straight edge of a piece of paper on the map so that it is touching both points of the map section being calculated. Mark the beginning and end of the cross-section, and write down the grid references and heights of each point.
2. Go along the cross-section line, making a mark every time a contour line touches the paper. Add any height numbers you see. Also mark the position of any main features, e.g. rivers or roads.
3. On graph paper, draw an x-axis and a y-axis to create a graph of what you have on the paper. The length along the bottom (x-axis) should be the same as your cross-section line on your paper. The scale on the side (y-axis) should be in 10 m intervals up to the maximum height in your cross-section.
4. Put your piece of paper along the x-axis and mark a dot on the graph for each contour line that is on the paper. The distance along the bottom should be the same as on the paper, and the distance up the side of the frame should correspond to the height of the contour line. If you don’t have a number for a particular line, count up or down from one you do have. Look out for places where the same contour line crosses the paper more than once. Remember: there is a gap of 10 m between contour lines, 100 m and 50 m lines are shown in bold and height numbers are towards the top of the slope.
5. Join the dots with a smooth line and check back to the map to make sure your cross-section looks sensible.
