Topographic Profiles 8. In this exercise you will draw a topographic profile from the map in Figure 6.14. Follow the procedure described: a. Draw a straight line 6 inches long through cross section A to AOn Figure 6.14 (red line). Clearly mark the ends of the line and label one A and the other AL(A prime). This is your reference line or baseline for your topographic profile. b. First, make a profile gauge: take a piece of scratch paper that is longer than the baseline (60And lay one edge along the line, as shown in Figure 6.5. c. Mark the placement of the ends and label them A and ACon the scratch paper profile gauge. d. Where contours intersect the baseline at the edge of the profile gauge paper, make a small tick mark on the paper perpendicular to its edge. e. Label each tick mark with the elevation of the contour. For the map in Figure 6.14, they will be 650 ft, 600 ft, 550 ft, and so forth. f. It is usually helpful to label each high point (hill or ridge) and each low point (depression or valley) along the profile gauge, as shown in Figure 6.5. You should be able to recognize when you have reached a high or low point because the same contour elevation crosses the baseline twice in succession and that makes the same elevation repeat along the gauge. E- Use the lines in Figure 6.6 to construct your topographic profile. Draw a straight vertical line at the left edge of the horizontal lines and label this A (as in Figure 6.7a). h. Lay the marked edge of the profile gauge horizontally along a line of your profile; match the tick mark labeled A on the gauge with the line labeled A on your profile. Now mark the location of ACat the other end of the profile, draw a vertical line at this location, and label it ALIYou should now have two vertical lines 6 inches apart on your profile in Figure 6.6. These two lines are the edges of your profile. i. Starting on the left of the lowest line, move upward and label every horizontal line with the elevations Oft, 50 ft, 100 ft, 150 ft, and so forth. If your elevations only go up to 500Cor less, you can label every other line; or if 3000 or less, every third line. You are now ready to draw your topographic profile. J. Find the highest elevations on your profile gauge. Lay your profile gauge horizontally along the line for that elevation in Figure 6.6, matching your A and ALands (see Figure 6.7a). Mark a tick on your profile for each tick on your profile gauge of the same elevation. In Figure 6.7, step 2 is shown for a 380-ft contour, step 3 at a 360-ft contour, then skipping down to step 8 at a 260-ft contour ( Figure 6.7a, b, and c, respectively). (Note: Your contours have different numbers.) Next, move the profile gauge down to the next line and mark ticks on Figure 6.6 for all ticks on the profile gauge at the next highest elevation. Continue this process until you have a mark on your profile for every tick mark on your profile gauge
