Reading and Interpreting Topographic Maps. Peaks and Valleys Select a Topic Terms Rules for Drawing Contours Tips for Interpreting Contour Patterns Test.
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Reading and Interpreting Topographic Maps
Peaks and Valleys
Select a Topic
Terms
Rules for Drawing Contours
Tips for Interpreting Contour Patterns
Test your Knowledge
Link to Topozone
~ Key Terms ~ Key Terms ~~
ElevationA term that describes the height of a point on
Earth’s surface above (or below) sea level. This point is 6300 feet (1920 meters) above sea
level.
http://www.math.montana.edu/~nmp/materials/ess/mountain_environments/novice/yosemite.jpg
Topographic MapA map that show the elevation of the land, such
as hills and valleys, using contour lines.
http://www.math.montana.edu/~nmp/materials/ess/mountain_environments/novice/yosemite.jpg
Contour Lines
http://www.topozone.com/map.asp?lat=35.16670759393963&lon=-106.71383553979156&s=25&size=l&symshow=n
Contour lines are lines connecting points of equal elevation. Every point along the line lies at the same elevation above sea level. Imagine walking around a hill in such a way that you never go up or down the hill, but stay at the same level. The trace of your path would be a contour line of that elevation.
Contour IntervalThe vertical distance between one contour line and the next. On any
map, the contour interval must be constant, and must be shown in the map’s legend. On this map, the contour interval is 20 feet, because each line represents a 20 foot increase in elevation.
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.
1200
1250
1150
Rules for Successful Contouring
Rule #2
Contour lines NEVER split or divide!
Can’t happen!
1200
1250
1150
1150
Rules for Successful Contouring
Rule #3
Contour lines cannot just stop. They must either form a closed loop, or run off the edge of your map.
What’s the elevation here???
1200
1250
1150
1100
?
This is fine!
?
Rules for Successful Contouring
Rule #4
Contour lines NEVER, EVER cross
What’s going on?? Is this area above or below 1200 feet?
1200
1250
1150
1100
?
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 topsHill 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.
Tip 4: What do those funny hachure marks mean?
Some features, such as the Grand Canyon, lakes, mines, or sinkholes actually are holes in the ground. The hachured contours indicate a depression. Don’t confuse it with a hilltop!
60070
0
800
TOPO QUIZNow its time to test your topography map
reading skills. Good Luck!!
1. If you traveled from point A to point B, would you be going uphill or downhill?
2. What landform do you think this map depicts?
a. Valley
b. Mountain
c. Plain
700 750
800
X825
A
B
Correct!
Sorry
• Actually, you would be going uphill. Look at the elevations on the
contour lines you will be crossing.
Sorry
3. In which direction does Maple Creek flow?
a. Northeastb. Southwestc. Can’t tell from infor
mation given4. What is the contour
interval of this map?a. 50 b. 100c. 400
Maple
Creek
800
700
600
500
5. What is the approximate elevation at the top of this hill?
a. 1240
b. 1300
c. 1000
6. Which hike would be steeper, from A to B or from C to D?
1200
1150
1100
C D
A
B
7. What is the contour interval of this map?
a. 20 feet
b. -20 feet
c. 60 feet
8. What type of landform is depicted here?
a. a mountain
b. a depression
c. a valley 20
4060
Link to Topozone
The USGS publishes topographic maps of the entire country. This website allows you to view any of these topographic maps.
Go to this site and use the map search to try to locate your city, town, school, or maybe even your own house. When you find a familiar area, examine the contours to see how well you recognize your own topographic features!
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