Transcript Topographical Maps PowerPoint
Topographic Maps
Show the Shape of the Land
What is a Topographic Map?
Imagine you are on a vacation with your family in a national park. You have a trail map but the map does not tell you anything about what the land looks like. Will you have to cross any rivers or valleys? How far uphill or downhill will you have to hike?
A topographic map tells you something about the topography or the shape of the land.
Topography
Is the shape, or features of the land.
Features can be natural (mountains, plateaus, plains) Features can be man-made (dams, roads) A flat map that uses lines to show Earth’s features.
Contour Lines
Wiggly lines on a contour map Show areas of elevation, slope, and relief
Elevation
How high above sea level an area is.
Can range from a few meters to several thousand meters above sea level.
Slope
Tells how steep an area is. The more gradual the slope, the farther apart the contour lines will be. The steeper the slope, the closer together the contour lines.
Relief
The difference between an areas high and low points. If you subtract the lowest elevation on the map from the areas highest elevation you get a measure of the area’s relief. Check: what is the difference between elevation and slope?
Elevation: height above sea level Slope: Steepness of the land
Rules for Successful Contouring Rule #1
Every point along a contour line represents the same elevation.
This entire line represents 1200 feet above sea level.
The space in-between each contour line is called the contour interval which tells you the change in elevation.
Rules for Successful Contouring Rule #2
Contour lines NEVER split or divide!
Can’t happen!
Rules for Successful Contouring Rule #3
This is fine!
Contour lines cannot just stop. They must either form a closed loop, or run off the edge of your map.
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What’s the elevation here???
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Rules for Successful Contouring Rule #4
Contour lines NEVER, EVER cross What’s going on?? Is this area above or below 1200 feet?
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Tip 1: What does contour line spacing indicate?
The closer together the contour lines are, the steeper the hill is. The more spread apart they are, the gentler the slope.
Traveling along the red line would be much steeper than traveling along the green line.
Tip 2: Which way is the stream flowing?
When contour lines cross a stream or river, they form v-shaped kinks in the lines that always point
upstream.
Also remember -Water always flows DOWNHILL!
Blue Creek flow towards the East.
Tip 3: Finding the hill tops
Hill tops are easy to find. Just look for the concentric closed contour lines that form the top of a hill. Notice the contour lines that form the two peaks below.
TOPO QUIZ Now its time to test your topography map reading skills. Good Luck!!
1.
2.
If you traveled from point A to point B, would you be going
What landform do you think this map depicts?
c.
A B X 825
3. What is the approximate elevation at the top of this hill?
a.
b.
C D 4. Which hike would be
or
A 1100 B
5. In which direction does Maple Creek flow?
Southwest Can’t tell from information given
6. What is the contour interval of this map?
Answers to Quiz
1) Uphill 2) Mountain 3) 1240 4) C to D 5) Northeast 6) 100