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 ContouringRule #1 Every point along a contour line represents the same elevation. This entire line represents 1200 feet above sea level. 1200 1150 1250
Rules for Successful ContouringRule #2 Contour lines NEVER split or divide! Can’t happen! 1150 1200 1150 1250
Rules for Successful ContouringRule #3 This is fine! 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??? 1100 1200 1150 1250 ? ?
Rules for Successful ContouringRule #4 Contour lines NEVER, EVER cross What’s going on?? Is this area above or below 1200 feet? 1100 1200 1150 1250 ?
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 QUIZNow its time to test your topography map reading skills. Good Luck!!
If you traveled from point A to point B, would you be going uphill or downhill? • What landform do you think this map depicts? a. Valley b. Mountain c. Plain 700 750 A 800 X 825 B
3. What is the approximate elevation at the top of this hill? a. 1240 b. 1300 c. 1000 4. Which hike would be steeper, from A to B or from C to D? C D 1200 B 1150 A 1100
800 600 5. In which direction does Maple Creek flow? • Northeast • Southwest • Can’t tell from information given 6. What is the contour interval of this map? • 50 • 100 • 400 700 500 Maple Creek