topographic-profile-assignment

Directions:

I have provided you with a section of the Topographic Map (Figure 2) from near Newport, PA, just north of Harrisburg, PA.The link for this map is provided below: https://ngmdb.usgs.gov/topoview/viewer/#14/40.5232/-77.0390 (You don’t “need” this link as we reproduce the relevant map as Figure 2.)

The cross-section that you will use has been drawn and labelled on Figure 2 with starting (A) and ending (B) points.You can draw this cross-section on the provided graph (Figure 3).

  • Using a scrap piece of paper, line up the edge of the paper along the cross-section line AB and transfer the locations and labels (elevations) of the beginning of the line (A), the end of the line (B), and any location where a bold topographic line intersects the cross-section line.You can do ALL of the topographic lines, but you will likely only need to use the bold lines to produce an relatively accurate profile.The contour interval on this map is 10 meters, and as is typical of most topographic maps, every 5th topographic line is bold.Thus the bold lines represent 50 meter intervals on the map (10 meters x 5 = 50 meters).This step is illustrated in Figure 1a.Only a portion of the lines have been included on this illustartion.You will need to label the locations of ALL points where a bold topographic line intersects your cross-section line.
  • Now you are going to transfer this data on to the graph provided in Figure 3.First, you will need to determine the range (lowest and highest) of elevations in your data from the topographic map and choose a scale for the vertical axis on the graph is Figure 3.Make sure your scale includes all the elevations from your data and the labeling on the vertical axis is in equal and consistent intervals. (see labeling of vertical axis in Figure 1b).
  • Lay your scrap paper with the data from the topographic map along the bottom horizontal axis of the graph and draw a vertical line on Figure 3 at each point for which you have a contour elevation data point (see Figure 1b).
  • Plot the data points on the graph and connect them with a single line representing the profile of the land surface along your cross-section line A-B.