Lab 7 Activity
Overview
For Lab 7 you will work on interpreting and drawing topographic maps, and drawing topographic profiles. All of the maps used in this lab are oriented so that north is toward the top of the map.
A. Basic Topographic Map Skills
A.1. The following topographic map (Figure 6.13) is from a coastal area. All contour lines are spaced at a 20 m contour interval.
a) Label the elevation of every contour line on the map. Remember: Elevations are measured in metres above sea level.
b) What is the elevation difference between the heavy contour lines? (I.e., if you were to stand on the one to the west, how would your elevation differ compared to if you were standing on the one to the east?) Explain your rationale.
A.2. Figure 6.14 shows five waypoints (A, B, C, D, and E) on a topographic map. The dashed lines are contour lines. The slope of the area is uniform.
a) Write your estimates for the elevation at each waypoint next to the waypoint.
b) How did you decide on the estimated elevations for points A and E?
A.3. Drawing Topographic Contours
Imagine you are a geologist working for the Geological Survey of Canada. You are tasked with creating your own coastal topographic map, so you hike around a coastal area with a GPS receiver (Global Positioning System) and every so often you record your position along with the elevation in metres at that point, which results in the map below (Figure 6.15).
Complete this map by adding in contour lines using a contour interval of 100 m. Draw the contour lines so that they are continuous: they will either continue to the edge of the map or form an enclosed circle. Your contour lines will generally fall between the GPS points on your map, so you will need to estimate many of the contour line positions. Be sure to label your contour lines.
A.4. Topographic Profile
Construct a topographic profile for the map in Figure 6.16 from position A to A’ in the space provided. Hint: It may help to label all of the contours before you start.
A.5. Vertical Exaggeration
Calculate vertical exaggeration on the topographic profile you constructed. Show your work. Hint: Start by writing both the map scale and the profile scale as a verbal scale (e.g., 1 cm = 50 m).
B. Topographic Map of Mt. Garibaldi Area, BC
B.1. Refer to Figure 6.17, the full Mt. Garibaldi topographic map.
Note: A re-scalable version of the British Columbia Topographic Map 092G095 can be found here: https://pub.data.gov.bc.ca/datasets/177864/pdf/092G/092G095.pdf
a) What is the ratio scale of the map?
b) Explain in a sentence how a ratio scale works.
c) Examining your map, you will see there is a black line that outlines a rectangle that takes up most of the map area. What is the latitude on the northern edge of this rectangle? Remember to indicate whether the latitude is north or south.
d) What is the longitude along the eastern edge of this rectangle? Remember to indicate whether the longitude is east or west.
B.2. Refer to Figure 6.18, showing Deadmans