Checking in…(p167)
 1. How do contour lines show elevation, slope, and relief?
 2. Why do contour lines never cross on a topographic map?
 4. For an area with gently sloping hills and little relief, would you
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draw contour lines close together or far apart? Explain why.
Answers:
1.The numbers on the contour lines show elevation. The distance between
contour lines shows slope. The differences between high and low places
show relief
2. Each one represents a specific elevation. Closed circles represent high
and low points; contour intervals are always the same for any given map.
4. far apart; the changes in elevation are gradual
Unit 2: Earth’s Surface
Chapter 5: Views of Earth Today
Chapter 6: Minerals and Rocks
Chapter 7: Erosion and Depositio
Chapter 5: Views of Earth today
Modern technology has changed the way we
view and map Earth
5.1: Maps and globes are models of Earth
5.2: Topographic maps show the shape of the land
5.3: Technology is used to map Earth
5.2: Topographic maps show the shape
of the land
 Before, you learned:
 Different maps provide information about natural and human-
made features
 Latitude and longitude are used to find places on Earth
 All flat maps distort Earth’s surface
 Now, you will learn:
 How contour lines show elevation, slope, and relief
 What rules contour lines follow
 What common symbols are used on topographic maps
Topographic maps use contour line to
show features
 Simple trail maps do not show you anything about what the
land looks like – rivers, hills, valleys?
 Topography – the shape, or features, of the land
 Can be natural: mountains, plateaus, plains
 Can be human-made: dams, roads
 Topographic map: a flat map that uses lines to show Earth’s
surface features
 contour lines show…
 Distance, elevation, slope, relief
Topographic maps use contour line to
show features
1.
Elevation: how high above sea level a place is
 Can be a few meters to several thousand meters above sea level
 Contour line numbers show elevation
2.
Slope: how steep a landform or area is
 the more gradual the slope, the farther apart the contour lines
 The steeper the slope, the closer together they are
3.
Relief: difference between the area’s highest and lowest
points
 Subtract the lowest elevation on a map from the highest
Contour lines follow certain rules
 Lines never cross – because each line shows an exact elevation
 Circles show highest and lowest points
lines form closed circles around mountain tops and hilltops, and also
depressions (sunken areas in the group)
 Sometimes the elevation of the mountain or hill will be written in the
middle of the circle
Contour lines follow certain rules
 Contour interval is always the same on a map
 Contour interval: the difference in elevation from one contour
line to the next
 This means the change in elevation between contour lines is always the
same
 Can differ from map to map
 Index contour lines mark elevations
 The darker contour lines on a map are “index contour lines”
 The lines where numbers showing elevation are often marked
 Not all lines are marked – to determine elevation, count the number of
lines from a numbered/index line, and multiply by the contour interval
Topographic Maps…
 Also contain symbols for natural and human-made features
 Cover urban, rural, and wilderness areas
 Are useful for hikers, campers, engineers, archaeologists,
forest rangers, biologists, and others…
What could this be?
 Contour Map
 Match the contour line drawing in the PHOTO
column with the corresponding contour line image
in the TOPO column.
 Hint #1: The Arrow in the TOPO images point
downhill.
 Hint #2: Don't get frustrated with the answers. A
couple are very similar.