From 3-D to Flatland and Back Again
Students lean how to read contour maps and, by extension, physical relief maps
by working through various activities of which some simulate contour mapping
and others require use of actual contour maps. These exercises will help the
students understand land forms and topography when looking at two-dimensional
maps and images, including remote sensing images.
Time Duration: two 50-minute sessions
Grade Level: 6-9
Concepts Explored: observation, analysis, measurement
contour, contour line, elevation, land forms, relief, topography, valley
Materials Day 1:
- washable or erasable marker or pen
- rubber bands
- blocks to support the pen
- contour map from Naturescope Geology: The Active Earth, p. 41; page
showing a horizontal grid with elevations corresponding to those on contour
- straight edge or ruler
- narrow cardboard strip (cut from an old file folder) for making tick marks at
contour lines and transferring contour information to the grid
Materials Day 2:
- Naturescope Geology: The Active Earth, p. 35-36 and 41 containing the
contour map and directions for making a contoured land form based on the map
- communities built by students or horizontal and aerial photos of them
- photo and maps of Salt Lake City from USGS What Do Maps Show?
- contour and physical maps
- copies of remote sensing images from
This lesson deals with looking first at an actual 3-D situation, the
first day, and then using such information to work with 2-D maps and images.
It also involves learning to understand changes in perspective from a
horizontal or oblique view to an aerial or bird's eye view. Such a change
reflects dramatic changes in human technology for viewing the earth.
From a horizontal perspective we can see land forms and heights, but we get a
distortion in shape and size. What we see in the foreground seems larger than
what is in the background, and we can see the detail in the foreground objects
better than in the objects in the background. An aerial perspective gives us a
different, perhaps more accurate, view although we do lose a sense of scale,
unless we remember what we have learned from looking at contour and physical
Remote sensing, employing thermal infrared wavelengths, digital scanning and
chemical techniques as well as aerial and satellite photography, offers a
fuller range of options for viewing the earth and making maps and images for
whatever portion of the earth we wish to observe. These studies in turn are
confirmed by additional ground-truth research. It must be remembered that the
initial mapping of the USA was done at ground level.
Procedure for Day 1:
- Assign students to teams of two.
- One student from each pair should make one of his/her hands into a fist
with the knuckles at the base of the fingers (hereafter referred to as the top
knuckles) pointing upward and the thumb tucked underneath and around the
(See Figure 1 above.)
The other student should prepare a maker by placing it on top of a block or
other support and securing it with a rubber band.
- The student doing the making should hold the marker and block in place and
make a line of equal "elevation" above the desk or table top around the hand of
the other student's middle knuckles, across the sides of the hand and the front
of the thumb, and over the wrist as that student moves his/her hand. The
student doing the marking should be sure to include the indentations that the
fingers make where they touch each other (very important for demonstrating one
of the land forms). Line A, Figure 1.
- Next, the student doing the marking should draw a line around the hand
midway between the middle and top knuckles. Line B, Figure 1.
- The student doing the marking should then draw a line around the top of the
knuckles. Line C, Figure 1.
- The students should then trade roles and repeat steps 3, 4, and 5.
- Each student should look at his/her fist in this position. It not only is
a fist in 3-D, but it also can represent a range of hills or mountains with
valleys in between, some of which could have been formed by streams and rivers.
What do the top knuckles represent? Is one of the knuckles higher than the
highest line drawn around the hand? What does that mean? Where are the
valleys? Which side of the "mountains" is the steepest? With their fists in
this position the students are essentially looking at them from a horizontal or
- Now each student should flatten out his/her hand with the fingers slightly
apart and straight and look at it from above. This is the aerial or "bird's
eye" view. By looking at the lines and noting how the indentations form Vs
that point toward the top knuckles, can you tell where the high points and
valleys are? Where are the lines farther apart? Closer together? What do the
relative locations of these lines mean? (Think back to the fist.) By
flattening you hand you have made a contour map - a 2-D representation of a 3-D
situation. The lines you drew on your fist correspond to contour lines and
thus give much information about topography by their shapes and relative
- Working individually, the students should examine their own copy of the
contour map from Naturescope, Geology, p. 41. They should look for the
high points, the low points such as the creek, the valleys, the marshland. Can
they determine where the hills are steeper or more gradual? Do they think
determining land forms from this perspective is easy? With experience they
should find it easier to decide what the relief or the topography of any land
area is when they look at a contour map.
- With the contour map flat on a desk or table, each student places a narrow
strip of stiff paper or cardboard, such as one cut from a file folder, across
as many of the contour levels as possible including the creek area. Then each
student should make a short tick mark on the strip where the it intersects a
contour line and write the contour level in feet next to each tick mark. Once
this step is completed, each student should then place the strip along the
bottom of the horizontal grid sheet provided, make an "x" at the appropriate
elevation level for each tick mark and connect the marks on the grid to give a
horizontal perspective of the contour map.
[Caution! Between the marks adjacent to the stream the student should
make a V-shape that does not dip to the next lower contour level. In a similar
way with the hills, the student should make rounded lines between the contour
levels at the same elevation that do not touch the next higher contour
- Another method for transferring information from the contour map to the
grid can be found in Activity Sheet #4 from What Do Maps Show? In fact,
the entire exercise could be done using the materials from this map kit instead
of from Naturescope.
- The students should be encouraged to observe and compare the two different
perspectives of the same area, then discuss them.
Procedure for Day 2:
- Following the completion of the lesson in day 1, the students should again
be assigned to work in pairs.
- They should then proceed to follow the directions given in Naturescope,
Geology, pp. 35-36, for making a cardboard contoured land form. The
students can then cover the contoured land form with aluminum foil and
carefully mold the foil to the contours to obtain the actual shape.
- An alternative to the cardboard model involves cutting out colored
construction paper, one color for each contour level, and putting together the
construction paper contours in the same way as the cardboard, but this can
involve the use and waste of a lot of colored paper.
- An extension to this exercise involves building the same contoured shape
with clear acetate sheets or clean, clear plastic snack boxes and then placing
them on top of one another in the proper order.
- With the materials from the previous exercises available for them to use,
the students should next look at the photos and images from their community
building project (if available), the USGS materials for Salt Lake City, and the
contour and physical relief maps and remote sensing images for
compare them and be prepared to discuss them with the class.
- In comparing the contour and physical relief maps, can they determine what
the heights of the shadows mean in the physical relief maps? Can they find
similar land forms in the
images? Can they find ridges or other high
places in the OTTER images?
Valleys? Rivers or streams? Human artifacts such
as roads? At which altitude above ground level can they begin to see these
details in the images? What purpose does each image serve? Which of the
altitude images corresponds better to the contour or physical relief maps?
These questions and others should help the student to become more comfortable
with observing and analyzing facts provided by maps and remote sensing
This activity is suggested to help with understanding scale and
resolution. In this case, the observer stands still and the object moves
toward the observer.
- Suggest that students go outside their homes in the evening after dark and
watch for airplanes landing at a nearby airport. When they first see a plane
approaching, what do they actually see? As the plane gets closer, what details
can they begin to see? The large white lights? The red and green lights? The
shape of the plane? The location of the various lights and actual parts of the
plane? The students are observing change in resolution, in detail as the plane
flies closer to them. In a similar way, remote sensing images have different
scales of resolution depending upon the altitudes at which they were obtained
and the purposes for which they were obtained. How much detail is necessary
for the desired information? Is the information wanted for a large or small
area? These questions and others are ones that can be asked during the study
of the OTTER
area as well as other areas. From looking at the
sensing images, what different details can be seen? In the image from 450
miles above (an
From 65,000 feet above (a
From 12,000 feet above (a
image)? From 5,000 feet above (a
image)? From 1500 feet above (a
In which images can rivers and highways be seen? Vegetation
differences? Human effects? Elevation differences?
- Assign a couple of students to seek information from nearby airports about
the distance in miles from an observer when the observer begins to see various
details about an approaching airplane.
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