Topographic Maps
Knowledge of Maps…
What are they?
What are they used for?
Why are they important?
Mr. Fetch’s Earth Science Classroom
Topographic Maps
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.
Mr. Fetch’s Earth Science Classroom
Mr. Fetch’s Earth Science Classroom
Contour Lines
Lines on a map that
connect points of equal
elevation
Every point on a contour
line has the same
elevation.
Contour lines NEVER
touch.
Mr. Fetch’s Earth Science Classroom
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.
Mr. Fetch’s Earth Science Classroom
Where the lines Come From
Topographic
Map (as seen
from above)
Actual
Land
Mr. Fetch’s Earth Science Classroom
Index Contours
The darker, thicker contour lines are called: INDEX CONTOURS
Typically every 5th
line on a Topo
map is an index
contour.
Mr. Fetch’s Earth Science Classroom
Topographic Profile
•Helps us to see the actual shape of land.
•Follow these simple steps to draw a profile:
5
10
15
20
25
25
20
15
10
5
Mr. Fetch’s Earth Science Classroom
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.
Find an index
contour.
Find an index
contour the is
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).
Mr. Fetch’s Earth Science Classroom
Contour Intervals
100
100
50
50
50
50
5
= 10
0
Mr. Fetch’s Earth Science Classroom
Rivers and Streams
•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
Mr. Fetch’s Earth Science Classroom
North
South
Mr. Fetch’s Earth Science Classroom
Shape of the Land
What do we notice about the shape of the land and the
arrangement of contours?
5
10
15
20
25
Mr. Fetch’s Earth Science Classroom
Steep and Gentle Slopes
STEEP SLOPES:
Contour lines are
close together.
GENTLE SLOPES:
Contour lines are far
apart.
25
5
5
10
15
20
25
5
Mr. Fetch’s Earth Science Classroom
Hills and Basins
Shown by closed-circles
o A hill: land that raises up-hill.
o A hill: land that raises up-hill.
When you see “hachure marks” you’re looking at a depression.
Example: A VOLCANO !!!
Mr. Fetch’s Earth Science Classroom
Hills and Basins
40
10
Mr. Fetch’s Earth Science Classroom
Hills and Basins
100
400
Mr. Fetch’s Earth Science Classroom
Hills and Basins
100
400
Mr. Fetch’s Earth Science Classroom
Topographic Maps
Reading in-between the lines …
• What is the
elevation at
point A?
100
50
0
= 20’
• What is the
elevation at
point B?
= 90’
Mr. Fetch’s Earth Science Classroom
Topographic Maps
Reading in-between the lines …
100
50
100
• What would the
terrain look like
if you were to
walk from point
A to point B?
Down hill, then
up hill.
Mr. Fetch’s Earth Science Classroom
Topographic Maps
Reading in-between the lines …
100
50
0
• What would the
terrain look like
if you were to
walk from point
A to point B?
Up hill.
Mr. Fetch’s Earth Science Classroom
Map Scales
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
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: ___________________ ?
So, If a map scale is, for example, 1:45,000…. Then:
1 cm = __________________ cm
1 paper clip = _________________ paper clips
1 ft = _________________________ ft.
100
100
50
0
Mr. Fetch’s Earth Science Classroom