Topographic Map Presentation

1. Knowledge of Maps…
What are they?
What are they used for?
Why are they important?
Topographic Maps

4. Maps that show
the change in
elevation of land.
Elevation is the
height of land
above the level of
the sea.
Elevation is shown
by contour lines.
Topographic Maps

5. Mr. Fetch’s Earth Science Classroom

6. Lines on a map that
connect points of equal
elevation
Every point on a contour
line has the same
elevation.
Contour lines NEVER
touch.
Contour Lines

7. Imagine it this
way…. Rising water
and Spray Paint !
Every time the water
rose, we painted the
level of the water.
We also plotted the
elevation of the water.
When the water receded, we were
left with the paint rings.
We just created contour
lines.
Everywhere on the line is
equal in elevation.
Look down from above to visualize a
topographic map.

8. Topographic
Map (as seen
from above)
Actual
Land
Where the lines Come From

9. The darker, thicker contour lines are called: INDEX CONTOURS
0
50
100
100
Typically every 5th
line on a Topo
map is an index
contour.
Index Contours

10. •Helps us to see the actual shape of land.
•Follow these simple steps to draw a profile:
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5
10
15
20
25
Topographic Profile

11. •Helps us to see the actual shape of land.
•Follow these simple steps to draw a profile:
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5
10
15
20
25
Topographic Profile

14. Find an index
contour.
Find the index
contour line right
BELOW the one
you just found.
Subtract the two
index contours.
Divide that
number by 5 (or
the number of
contour lines
between the two
index contours).
Contour Intervals
•The word interval means THE DIFFERENCE BETWEEN.
•When you go from contour line to another the elevation changes.
•The difference in elevation from one line to another is called the CONTOUR INTERVAL.

15. 0
50
100 100
50
50
50
5
= 10
Contour Intervals

16. •Shown by V-shaped contour lines.
•V’s point in the direction water is COMING FROM.
Water always moves from up high…to down low
(higher contours to lower contours).
NORTH
SOUTH
Rivers and Streams

17. North
South

18. What do we notice about the shape of the land and the
arrangement of contours?
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Shape of the Land

19. 252015105
5 5
25
GENTLE SLOPES:
Contour lines
are far apart.
STEEP SLOPES:
Contour lines are
close together.
Steep and Gentle Slopes

20. Shown by closed-circles
o A hill: land that raises up-hill.
o A Basin: a depression in the ground
shown by hachure lines.
When you see “hachure marks” you’re looking at a depression.
Example: A VOLCANO !!!
Hills and Basins
Hachure Lines:
• Hachure lines are
regular contour lines
with small segments
sticking out from it.
• The first hachure line is
at the same elevation as
the contour line before
it.
120
120
140

21. 10
40
Hills and Basins

22. 400
100
Hills and Basins

23. 400
Hills and Basins
200

24. Reading in-between the lines …
• What is the
elevation at
point A?
= 20’
• What is the
elevation at
point B?
= 90’
0
50
100
Topographic Maps

25. Reading in-between the lines …
• What would the
terrain look like
if you were to
walk from point
A to point B?
Down hill, then
up hill.
100
50
100
Topographic Maps

26. Reading in-between the lines …
• What would the
terrain look like
if you were to
walk from point
A to point B?
Up hill.
0
50
100
Topographic Maps

27. Map Scales
o Maps are not LIFE-SIZE.
o A scale converts the size of something on a map to its actual size in real life.
A ratio, such as 1:80,000 (spoken as 1 to 80,000) means:
 That for 1 unit on a map = 80,000 units in real life.
Map Scale: 1: 80,000 = 1 inch
Example:
 Look at the map below.
o The scale is 1:80,000
o I measure a distance of 1 inch between both rivers.
o But in real life, the rivers are: ___________________ ?
0
50
100
100
Map Scale: 1: 80,000
So, If a map scale is, for example, 1:45,000…. Then:
1 cm = __________________ cm
1 paper clip = _________________ paper clips
1 ft = _________________________ ft.
Map Scales

28. •Helps us to see the actual shape of land.
•Follow these simple steps to draw a profile:
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5
10
15
20
25
Topographic Profile

29. SLOPE
• The slope of a line indicates the
topography’s steepness.
Distance km
E
l
e
v
a
t
i
o
n
“The steeper the slant, the
greater the slope”
ft.

30. SLOPE = RISE (Y) / RUN (X)
Rise (Elevation)
Run (Distance)
Distance km
E
l
e
v
a
t
i
o
n
0 1 2 3 4 5 6 7 8 9
0
1
2
4
3
5
6
7
10
8
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ft.

31. What is the slope of A – B?
0
50
100
Map Scale: = 1 km

32. Calculate slope of all the lines
Slope = Rise (Contour Lines)
Run (Map Scale)
Slope = 90 ft – 20 ft = 70 ft
1 km 1 km
Slope = 70ft/km