Topography
Topography
• The Shape of the
land
Topography of
an area is
determined
by:
• Elevation:
• Relief:
High relief
Low relief
• height above sea
level
• difference in
elevation (highest
point and lowest
point)
• Landform
• a feature of
topography
(the top of the
Earth)
• Topography
shows us:
• Landforms,
elevation and
relief of each
area.
Pair Share
Partner A: What is
elevation?
Partner B: Explain
the elevation of
the plan
Pair Share
What is relief?
Explain the relief in the
picture.
Pair Share
What is Landform?
Explain the different landforms
in the picture:
• What is a
topographic
map?
• Maps that show the
surface features of
an area.
• The shape of the
• Topographic
land.
maps provide
– Elevation
information
about:
– Relief
– Slope
• Contour Lines:
• lines on the map that
connect points of equal
elevation
• Contour
interval:
• change in elevation from
one line to the
next…imagine each line
like a step up or down
Contour lines
Relationship between topographic features and contour lines
Let’s take a walk up a
hill!
We’re now at an elevation of
100 meters.
100m
Let’s keep going!
100m
Now we’re at 200m.
200m
100m
Shall we march on?
200m
100m
We’ve made it to 300m!
300m
200m
100m
On to the peak!
300m
200m
100m
We’re on the peak, but
what’s our elevation?
300m
200m
100m
Any ideas?
Let’s add contour lines for every
50 meters and see if that helps.
300m
200m
100m
We know that we are above 350m,
but less than 400m.
350m
300m
250m
200m
150m
100m
50m
Let’s head down the hill, it’s
getting late!
350m
300m
250m
200m
150m
100m
50m
Now what’s our elevation? White
Boards:
If you said somewhere between
200m and 250m you are right!
350m
300m
250m
200m
150m
100m
50m
Let’s try this again!
350m
300m
250m
200m
150m
100m
50m
What’s our elevation now?
If you said 50m or just under, you’re
right!
350m
300m
250m
200m
150m
100m
50m
Let’s
now look at the
same hill, but the
way we might
see it from an
airplane!
Each color change represents a 50
meter increase.
Features of Topographic Maps
Relationship between 3D and 2D
representation
3D view
2D view
Pair Share: What does it
mean if the contour lines are
close together?
Pair Share: What does it
mean if the contour lines are
far apart?
Notice how the contour lines are used to
show how gentle or steep the slope is.
Why would it be important
to know if something was
steep or gentle slope?
Sometimes on maps you will
see dark colored lines?
• Why do you think they have dark
colored contour lines on the map?
Index
Contours
• An index contour is a contour
line that is thicker or darker.
• Index contours occur every
fifth contour line.
Hills
• Represented by a
series of contour lines
in a rough circle
Streams
• looks like an upside
down V.
• It opens in the
direction the water is
flowing.
Depressions
• Show indents.
• Drawn with marks on
the inside.
Pair Share
1. What are index contours and how are
they shown on the map?
2. Why are index contours important?
3. If you were to create a topographical
map what would it look like if you
were to try and show a hill?
4. If you were to create a topographical
map what would it look like if you
were to try and show a depression or
stream?
Topographic maps also identify natural
structures and structures made by
man.
Topographical Map
1250
1000
1000
1500
2500
2. What is
the
contour
interval of
this map?
2250
2000
1750
1000
1. Name
the highest
elevation
shown for
this
volcano.
1500
1250
1000
3. What is the elevation of
Point B?
Point B sits right on the 10 ft contour line. Since
all points on this line have an elevation of 10 ft,
the elevation of point B is 10 ft.
4. What is the elevation of Point C?
Point C does not sit directly on a contour line so we can not
determine the elevation precisely. We do know that point C
is between the 10ft and 20 ft contour lines so its elevation
must be greater than 10 ft and less than 20 ft. Because
point C is midway between these contour lines we can
estimate the elevation is about 15 feet (Note this assumes
that the slope is constant between the two contour lines,
this may not be the case).
5. What is the elevation of Point
D?
We are even less sure of the elevation of point D than point
C. Point D is inside the 20 ft. contour line indicating its
elevation is above 20 ft. Its elevation has to be less than 30
ft. because there is no 30 ft. contour line shown. But how
much less? There is no way to tell. The elevation could be
21 ft, or it could be 29 ft. There is now way to tell from the
map.
6. What is the elevation of Point
E?
Just as with point C above, we need to estimate the
elevation of point E somewhere between the 0 ft and 10 ft
contour lines it lies in between. Because this point is closer
to the 10 ft line than the 0 ft. line we estimate an elevation
closer to 10. In this case 8 ft. seems reasonable. Again this
estimation makes the assumption of a constant slope
between these two contour lines.
Review Questions
1. How are contour lines drawn on
maps?
2. How does a contour map show
whether a slope is gentle or
steep?
3. Describe at least four natural or
man-made structures that can be
shown on a topographic map
How’s It Used?
Can you think of some ways a
topographic map might be used?
Topographic Maps are used in:
–
–
–
–
–
–
Geographic Planning
Architecture
Civil Engineering
Earth Sciences
Mining
Hiking
Warm-up #5
Write if each example of chemical or
mechanical weathering.
1. Halite in rocks is dissolving.
2. Acid from plant roots break up the
rock.
3. Wind blows sand around cutting at
the side of a mountain.
4. Carbonic Acid dissolves limestone
creating a stalagmite in a cave
5. A rock turns red due to oxidation
6. A rock becomes smaller as it
travels down stream.
Warm-Up # 1
• What is a contour line?
• A line that connects points of equal
elevation.
• What are 4 major agents of
erosion?
• Water, wind, ice and gravity
• What is the dominant agent of
weathering and erosion.
• Water
Warm-Up # 5
1. What is a contour line?
2. The change in one elevation
to the next is called?
3. A ____ map shows the surface
features of an area.
4. Explain how weathering,
erosion and deposition change
the topography of the land?
Warm-Up # 6
1. What is a contour line?
2. Describe the difference between
a high relief and a low relief.
3. Draw a:
a. Depression
b. Hill
4. What causes iron to rust?
5. What type of weathering is it when
water dissolves a rock?
Warm-Up # 3
1. What is a contour line?
2. Describe the difference between
a high relief and a low relief.
3. Draw a:
a. Depression
b. Hill
Warm Up 3
What is the elevation at A:, B:, C:, D: E:?