Name Period Topic 2B Topographic Maps Isolines: Contour lines: Contour Interval: Index Contour: The elevation when starting at the OCEAN must be. The contour interval on this map is feet.
2 0 50 E The contour interval on this map is feet. Point D has an elevation of. Point E has an elevation of. Point A has an elevation of. Make an observation or two about the map on the board. Remember: Not all maps have contour lines that start at! This is an Island! Ocean Note:
A depression is:. It could be a meteor crater, a large empty lake or volcanic crater. 3 Depressions on a topographic map are indicated by lines. ( = ). The rule to remember is Ocean Contour interval is 25 feet Questions: 1. Where is the depression on this map? 2. The hatched line that point B is on is right next to the contour line A is on. What is the elevation of point A? 3. Following the rule for depression lines, what would be the elevation of point B? 4. Draw another hole around Point Y. What is the elevation of this hole?
4 Stream flow on a Topographic map Streams and rivers usually flow into a larger body of water, but not always Tips for determining stream flow: 1. 2. What direction is the stream flowing towards? What direction is the stream flowing from? What direction is the river flowing on the map on the board?
5 Gradient: Gradient= change in field value (elevation) Distance (measure on the map) Question: A plane travels for 3,500km and its elevation goes from 0m to 9,800km. What is the gradient of its trip?
6 Of the two gradients above, which one is steeper, A-B or X-Y?
7 Which side of Mato Hill has the steepest slope? Steep slope (gradient): Gentle slope (gradient): Remember:
Which is the quicker route from the visitor center to Madison? Traveling following the arrow or following the road? 8 Why? How to measure a Highway or Railroad track on a Topographic Map There are two ways to measure the distance between point A and B seen below. You can measure the distance directly across (like the bird flies) as we do when we calculate gradient, or you can measure the true distance along the road. Questions: 1. Measure the distance directly across from A to B. The distance is miles. 2. Now, measure the true distance along the road. The actual distance is miles. 3. Why did the 2 nd method you used give you a more accurate measurement?
Match the profile to the map by placing the letter that is next to the profile to the corresponding topographic map. Use each letter once. 9 C
10 Making a Profile 1. Label all of your contour lines with their elevation. 2. 3. 4. 5. 6.
11 20 40 60 50 40 30 20
12 Determining the Highest Elevation on a hill: Hills are usually rounded at the top. 1. Determine the contour interval and add that number to the LAST contour line on the hill. a. That is what the next contour line would have been! b. Since the map does not show that line. 2. The highest point cannot be that high, so you must subtract one! Determining the Lowest Elevation of a Depression: 1. Determine what the next contour line would be. 2. Add one to that number. Contour interval is 10. Next line would be 20, but there is no 20 line. Add 1 to that line and you get your answer. 20 + 1 = 21
13 1
14 H 1. Measure the distance along Debra road from point 1 to 2. 2. What is the contour interval of this map? 3. In which direction is Linda River flowing? 4. Calculate the gradient between points E and D. Show all work! 5. What is the elevation of point H? 6. What is the highest possible elevation of point A? 7. Which side of Adam Hill is the steepest? (Use a compass direction?)
15 Vocabulary 1. Contour line: 2. Contour Interval: 3. Depression: 4. Elevation: 5. Gradient: 6. Isoline: 7. Profile: 8. Slope: 9. Field: 10. Model: 11. Topographic Map: