Laboratory Manual for Introductory Geology 4e

EXERCISE 8.1
Which Image Works Best?
Name:
Course:
Section:
Date:
(a) Examine the images in Figure 8.1 and use the table below to rank them on a scale of 1 to 4 by how well they show
the map elements indicated (1 is most effective and 4 is least effective). Ties are allowed.
Map element Topographic map Aerial photograph Landsat image DEM
Location
Distance
Direction
Elevation
Changes in slope
Names of features
(b) Which of the images enables you to recognize the topography most easily? Why?
(c) Which is least helpful in trying to visualize hills, valleys, and lakes? Why?
(d) Erosional agents often produce an alignment of elongate hills, ridges, and valleys called the topographic grain.
Which images show the topographic grain in this area most clearly? Once you’ve seen it on those images, can you
recognize it on the others? Use a marker or colored pencil to draw the alignment direction on each image.
(e) Which images show highways most clearly?
(f) Which images show unpaved lumber roads most clearly?
(g) Study the details of what is shown in each image. Which image do you think is the oldest? The most recent? Explain
your reasoning.
200 CHAPTER 8 STUDYING THE EARTH’S LANDFORMS: MAPS AND OTHER TOOLS