Lesson 4How to Read a Topographic Map

Document Sample

Lesson 4–How to Read a Topographic Map
Key teaching points                         Suggestions for teaching                      Ask students to answer these ques-
this lesson (3, 35-minute sessions)           tions and fill in their answers on
A topographic map is a representa-                                                        Activity Sheet #4:
tion of a three-dimensional surface on      On the poster is a topographic map
Which is higher, hill A or hill B?
a flat piece of paper. The digital eleva-   of Salt Lake City. This lesson will help
tion model on the poster is helpful in      students learn how to read that map.
understanding topographic maps.             Learning to use a topographic map is
Which is steeper, hill A or hill B?
a difficult skill, because it requires stu-
Contour lines, sometimes called "level      dents to visualize a three-dimensional
lines," join points of equal elevation.     surface from a flat piece of paper.
3. Compare a topographic map to a
The closer together the contour lines       Students need both practice and imag-
picture of the same place. Now have
appear on a topographic map, the            ination to learn to visualize hills and
the students look at the topographic
steeper the slope (assuming constant        valleys from the contour lines on a
map of the same two hills. Say, "The
contour intervals).                         topographic map.
lines you see on this map are called
contour lines. Can you see why they
Topographic maps have a variety of          A digital terrain model of Salt Lake City
are sometimes called `level lines'?"
uses, from planning the best route for      is shown on the poster. This three-
Ask the students to trace with their fin-
a hike to determining a location for a      dimensional drawing, created from
gers around the 40-foot contour line on
school or an airport.                       computerized data, is a helpful transi-
the map. Then ask them to look at the
tion step for students as they learn to
picture of the hill and draw their fingers
How this lesson relates                     visualize the shape of the land from
around the 40-foot contour line.
to the geographic themes                    contour lines.
Then ask the students to draw their fin-
Location and place—Using a topo-            1. Discuss the word "topographic."
gers along the 20-foot contour line on
graphic map can give students a clear       Remind students that there are many
the topographic map. Then draw their
understanding of the physical and           different types of maps. Tell them that
fingers along the 20-foot line on the
manmade characteristics of a location.      they are going to learn about a specific
picture of the hill. This exercise will
The topographic map allows for a clear      type of map—the topographic map.
help those students who are kines-
understanding of such physical fea-         Begin the lesson by introducing stu-
thetic learners.
tures as mountains and canyons.             dents to the word "topographic." Write
the word on the board. Tell students
Relationships within places—Using the       the word is derived from two Greek
tion and fill in the answer on
topographic map, students can see           words—"topo," meaning "place," and
Activity Sheet #4:
why some things are where they are.         "graphos," meaning "drawn or written."
They can see how people have adapt-         Ask students if they can use that infor-      • How many feet of elevation are there
ed to the physical characteristics of a     mation to figure out what "topographic"       between contour lines?
particular location.                        might mean. Then ask a student to             (Answer: 10 feet)
look up the word in the dictionary to
Movement—Students can begin to              see whether the guess was correct.            Show the students that some contour
understand how the topography of a                                                        lines are thicker than others. These
location influences the transportation      2. Hand out Activity Sheet #4. The top        "index contours" include labels to
and communication within that area          illustration introduces students to con-      make it easier to read elevations from
and with the rest of the world.             tour lines. Point out that a contour line     the maps.
joins points of equal elevation. Think of
Materials you need                          it as an imaginary line on the ground         Ask students to answer these ques-
for this lesson                             that takes any path necessary to main-        tions and fill in the answers on
tain constant elevation.                      Activity Sheet #4:
A copy of Activity Sheet #4 for
each student.                               First, have the students look at the          • How high is hill A?
side view of the hills. (Bottom of the          (Answer: about 42 feet)
illustration)                                   Hill B?

• Are the contour lines closer together
on hill A or hill B?
Lesson 4–page 2

Help students understand that the closer      • Locate a stream that flows into the main    • What is the approximate elevation of the
the lines, the steeper the slope. Have stu-   river. Draw a pencil line down that stream.   State capitol?
dents point out other places on the map       Put an X where the stream joins the main      (Answer: 4,500 feet)
that have a very steep slope.                 river. On a real topographic map,
streams are shown in blue and contour         Would you be walking uphill or downhill to
4. Introduce students to other information    lines are shown in brown.                     go from the State capitol to Pioneer Park?
shown on a topographic map. Now have                                                        (Answer: downhill)
the students look at the picture on page 2    5. Discuss how topographic maps are
of the activity sheet.                        used. Maps are developed for special pur-     • Suppose you lived by Fremont School.
poses. Topographic maps are used in a         Find at least three ways you could get
Have students identify and circle these       variety of ways.                              from your house to the State capitol. List
features on the illustration 2 of Activity                                                  things you would see along the way.
Sheet #4:                                     How might you use a topographic map
if you were selecting:                        Additional activities for follow-
• A church                                                                                  up
• A route for a hike.
• A bridge over the river                     (Choose route that's not too steep. When      The topographic map shows that
planning a long hike, you may want to see     Salt Lake City has a Pony Express
• An oceanside cliff                          whether water is available or whether it      Monument near the State capitol.
• A stream that flows into the main river     cate whether the route is shaded.)            Pony Express and why this monument is
located in Salt Lake City.
• A hill that rises steeply on one side and   • The best location for an airport.
more smoothly on the other.                   (Make sure airplanes have plenty of room
to take off and land before the ground
Have students identify and circle the         rises. Do not let students suggest building   Return to "What Do Maps Show" Home
same features on illustration 3 of            in a swamp, in the woods, or in a built-up    Page
Activity Sheet #4.                            area.)

• Draw the map symbol for a church.           • A route for a new road.
(Find a shallow grade rather than a steep
one. Do not allow them to cross too many
rivers because bridges are expensive.)
• Draw the map symbol for a bridge.
6 .Working with the topographic map in
the map packet. Now that your students
have a basic understanding of how topo-
• Put an X on the oceanside cliff.            graphic maps work, here are some ques-