| From Classbrain.com Lesson Plans Teaching With Topographic Maps - 25 Ideas for Educational Lessons Author: Although many other scales exist as well.Topographic maps represent a fantastic resource for educators. They can be used in a variety of ways in the science, math, geography, and history curriculum, from elementary to college level. The following ideas have been compiled by Joseph Kerski to be used as an aid in building educational lessons. Topographic Maps Tutorial from the Geospatial Training and Analysis Cooperative, Idaho State University: Includes sections devoted to `What is a Map?, Reference Datum, Map Projections, Distortions, Grid Systems, Geographic Coordinates, UTM, State Plane, Public Land Survey, Using Topo Maps, Map Scale, Magnetic Declination, Vertical Scale, Creating Profiles, Vertical Exaggeration, Calculating Slope, Using a Compass, Setting Magnetic Declination, Get a Bearing, Go from A to B, Find Self on a Map, and four field exercises using topographic maps. http://geology.isu.edu/geostac/Field_Exercise/topomaps/index.htm Dr Slaymaker's Topographic Maps and Aerial Photographs Web Pages: http://www.csus.edu/indiv/s/slaymaker/
Educational Map Catalog: http://rockyweb.cr.usgs.gov/public/outreach/mapcatalog/
USGS Map Store: Sample images from USGS Topographic Maps: Visit: http://mapping.usgs.gov/mac/isb/pubs/booklets/usgsmaps/usgsmaps.html How To Obtain Topographic Maps: Visit http://mapping.usgs.gov/mac/findmaps.html Topographic Map Symbols: Visit http://mapping.usgs.gov/mac/isb/pubs/booklets/symbols/index.html
1. Global Positioning System and
Coordinate Systems
Divide students into groups and have them determine, to the nearest second, the latitude and longitude of the school using a 1:24,000-scale topographic map covering the school and surrounding area. Discuss need for accuracy. Use a 1:100,000 and a 1:250,000-scale map of the same area and discuss the difficulty of determining position depending on the map scale. Discuss base 60 with reference to time, and transfer discussion to base 60 with latitude-longitude degrees-minutes-seconds. Discuss the process of interpolation. Draw a 2.5-minute grid on interior of USGS 1:24,000-scale topographic map using 2.5-minute tic marks on margin of map as a guide. Write answers from all teams on the board. Next, go outside and record positions with GPS receiver; stay out at least 10 minutes for the most accurate averaging. Go back to classroom. Compare reading from GPS receiver to that of each team. Which team was closest? Repeat the above with the UTM (Universal Transverse Mercator) coordinate system. UTM coordinates are drawn in blue tic marks with a 10,000 meter interval. Compare the convenience of units expressed in meters with UTM versus those expressed in seconds (with lat/long).
Discuss the accuracy of your GPS unit.
Discussion: Oftentimes the students will be too willing to discard their own interpolations from the topographic map and willing to accept a high-tech device, despite its accuracy limitations
(particularly a low-end unit).
Many times, the student's interpolations will be more accurate, particularly with the z reading (elevation).
Discuss why this is so - triangulation with satellites, Selective
Availability error code with units, obstruction by buildings, limited time to collect coordinates, etc.
2. Locating Benchmarks - Surveying
Materials Required: Topographic map,
benchmark (optional).
Discuss benchmarks - why they are important in mapping, to make maps more accurate in x , y, and z. Why do peoople demand accuracy in maps?
Discuss the uses of maps, and which data users require accuracy. Discuss laying of pipeline requirements as opposed to locating climatic zones. If possible, obtain a benchmark from surveying company or catalog and show class.
Show topo map symbols sheet and have students find benchmarks on map. Discuss why certain areas (tops of mountains, railroad track sidings, etc) are better for locations to mount benchmarks than others.
Discuss the permanency vs transitory nature of these features vs mounting the benchmark in sand or in a tree.
Look at the http://www.ngs.noaa.gov
site at the National Geodetic Survey for discussion on surveying. Discuss triangulation and leveling techniques. If possible, go on field trip and try to find one or more of the benchmarks the students have found on
the topographic map.
3. Geographic Coordinate System - Convergence
Discuss the convergence of longitude lines at the poles by illustrating the concept first on a globe. Show topographic maps in North Dakota versus those in Louisiana or Hawaii, illustrating why those in North Dakota are narrower in the east-west direction than Louisiana/Hawaii. Measure the differences. Discuss: Why don't the latitude lines converge?
4. Comparing Coordinate Systems
Discuss geographic coordinate system (lat/long) vs UTM (use USGS fact sheet on UTM coordinate system) vs state plane coordinates. Use state highway maps or other state-based maps or county maps in state plane coordinates. Why are map projections used? What
is the relationship between map projections and coordinate systems? Why are different systems used? Who are the data users that require one over the other? Discuss state vs global needs. When does coordinate
system have an advantage over another?
5. Precision of Coordinates
Discuss precision of lat/long readings, and why hours has to be divided up into minutes and seconds for precision. Analogy: If I were to meet you after school, I might say 4:00pm, and if you and I showed up at 3:58 or 4:02, it would not be that important. However, if you were launching the space shuttle, it is critical that you state the launch will be at
4:00.0355. In the same way, if you were constructing a pipeline you would need more than degrees of lat/long, you
would need precision down to the tenths of a second of latitude and longitude of its location.
6. Absolute versus Relative Location
Discuss absolute location versus relative location. What is the difference between 42 07 31" lat / 101 15 31" long versus the phrase "northeast of Pleasant Grove"? When is absolute location important, and when is relative location important? Which one(s) does GPS measure?
7. Map Projections
Ask students to examine the map projection of the chosen topographic map and other maps. Discuss the advantage and disadvantage of different map projections. Why do Greenland and Canada look so large on a Mercator projection? Illustrating distortion with map projections is great to do with a GIS by drawing a circle and seeing how it is distorted with different projections, and how the distance from Honolulu to Los Angeles varies, and how the angle varies.
Show globe and topographic maps. Why does the process of drawing the earth on a two dimensional piece of paper cause distortion?
Use USGS poster (available from the USGS) on map projections as well as cartography texts to illustrate how distance, direction, angle, or area have to be distorted. When is it best to distort
distance/direction/angle, or angle? If you had to choose 3 of the 4 attributes to keep accurate, what would they be?
Illustrate how choosing the map projection depends on the application. Illustrate how the projection of the map is more evident on a small-scale than a large- scale map.
If possible, read sections of book "How to Lie with Maps" (Monmonier).
8. History of Cartography
Examine how maps were made in the past. Obtain some negatives and scribing materials from a film or drafting company. Obtain a scribing instrument; a sharp nail or compasses end will suffice. Pencil in some contour lines on the film and have students try to follow them with the scribing instrument. Discuss the fact that most topographic maps were prepared using manual scribing instruments.
Ask why film was used rather than paper.
Discuss the national map accuracy standards and the scientific principal of shrinking and swelling of materials with temperature. Film shrinks and swells less than paper.
Use USGS Teachers Packet "Exploring Maps."
This packet contains two posters illustrating historical maps back to the Babylonians.
Use samples from "Mercator's World" or other historical map journal.
Illustrate with samples from the Library of Congress map WWW page.
9. Modern Cartography
Discuss geographic information systems (GIS), and the capability of drawing all points, lines, and areas on the computer. Ask the students what the advantage is of making maps on the computer vs by hand. Advantages include the ability to easily change the symbology, projection, scale, and then to have the map layers available for analysis in a GIS.
Visit WWW sites running Internet map server software, where students can construct a map with a web browser. Look at
http://rockyweb.cr.usgs.gov/public/outreach/
for a list of some of these sites.
10. Aerial Photo Interpretation
Obtain an aerial photograph of an area from the USGS (use PhotoFinder at
http://edc.usgs.gov/Webglis/glisbin/finder_main.pl?dataset_name=NAPP)
and then a topographic map covering the same area. Ask
students how they can identify a stadium, lake, school, office building, stream, mountain, and other features on an aerial photograph. The world is more complex than is at first realized. Schools may have an athletic track if a high school, but what about in a dense urban area? Do they always have a track?
Ask students to identify the time of year that the photograph was taken. What are the clues? Ask students to identify the time of day the
photograph was taken? What are the clues? What is the best time to take a photograph if you were going to make a map from the photograph? Near solar noon is best to minimize shadow. Near the summer solstice is best also to minimize shadow, except in heavily timbered areas, when "leaf-off" times are best in March and November.
11. Analysis of Stereo Aerial Photographs
Discuss the need to see the world in three dimensions for creating contour lines. Show "magic eye" images. Can the students see them in three dimensions? Obtain stereo viewer and obtain stereo aerial pairs. Hubbard Scientific is one vendor of these.
If students have difficulty, tape the photographs on the table in the correct overlap position. Use the aerial
photo finder at the USGS at http://edc.usgs.gov/Webglis/glisbin/finder_main.pl?dataset_name=NAPP
to illustrate the concept of consecutive photographs along a single flight line to obtain stereo.
12. Creating Maps from Aerial Photographs
How should each feature be mapped such as the map doesn't become too complicated or cluttered? Use topographic map symbols. Make maps with TODALSIGS--Title, Author, Date,
Author, Legend, Scale, Index, Grid, Source. How can students decide which features should be mapped? Discuss the reason why the real world needs to be simplified to make a map. For every theme that is drawn on a map, there are themes that are omitted (for example, soils).
13. Analyzing Physical Features on Topographic Maps
Examine at the list of physical features on
http://rockyweb.cr.usgs.gov/public/outreach/,
such as eskers, drumlins, glaciers, bajadas, canyons, mesas, coastal features, sand dunes, marshes, floodplains, volcanoes, alluvial fans, karst, and so on. How are these features identifiable on topographic maps?
What are the sizes of each of these features?
What is the most suitable scale with which to examine the entire physical feature? How do physical features affect population settlement amount and patterns?
14. Analyzing Change on Topographic Maps
Obtain historical prints of topographic map from USGS, and compare to latest printed edition. What are the reasons for land use change? Which areas change much, and which
areas change little, and why? From what direction and what is the magnitude of the forces that cause land use change, locally, regionally, and nationally? Examine 1:24000, 1:100,000, and 1:250,000-scale maps to answer these questions. For example, is there an urban area to the west of the area under study that is causing the changes?
Discuss physical changes versus human-caused change. Examples of maps with physical changes include Earthquake Lake MT, South
Pass LA, and Mt St Helens, WA.
Examples of maps with human-caused change include any map containing a reservoir or urban area. Have students speculate and draw what the area will look like in 10, 20, and 30 years from now. Look at the Map Mysteries lessons on http://rockyweb.cr.usgs.gov/public/outreach/mapmys.html
for more ideas.
15. Analysis of Impact of Public
Land Survey System (PLSS)
Discuss the 1785 Ordnance Survey that Jefferson signed into law. Obtain "baselines and meridians" Public Land Survey map from USGS that shows the spread of the township and range system for dividing up land for settlement,beginning in Ohio and spreading west. Discuss why Texas has no PLSS (separate country for a time). What is the impact of this system on the rural landscape? Compare land in Virginia - - roads and boundaries - - versus that in Kansas. What is the impact of this system on the urban
landscape? Show maps of cities in PLSS states versus cities in non-PLSS states. Note, for example, the regular grid in Phoenix vs the irregular pattern of Atlanta. Emphasize how an act from 1785 continues to affect the routes we took to get to school today! Illustrate this land division versus long lot system of the lower Mississippi River floodplain.
16. Creating Profiles
Draw cross-sections (profiles) along several transects across the topographic map, from analyzing contour lines. Where is the topography steepest? Flattest? Why?
What forces are most active on the landscape in this area? Landslides? Floods? Erosion? Tectonism? Coastal storms? What forces were most active in the past?
Glaciation? Were the past forces the same as today's forces?
Compute the slope in percent and in degrees. Have students plan a railroad and a road from point A to point B through a mountainous region. Give students a constraint of 8% for the maximum road grade and 2% for the maximum railroad grade. Compare students routes.
Show map with railroad on it in another area, and have students compare the number of twists and turns, and calculate distance, between roads and railroads.
17. Analysis of Map Scale Using Point Reyes, California
Discuss map scale. Large scale map 1:24,000 is a larger number (fraction) than a small scale map (1:100,000).
When would you need a map at a large scale versus a small scale? One example of scale difference in answering a question: Is California splitting off into the Pacific Ocean?
Examine Point Reyes CA map. At this scale, yes, it is "splitting", in the sense that the land over the San Andreas
Fault has sunk to the point where the Pacific Ocean has flooded the area. At a smaller scale, no, the land is not "splitting off" into the Pacific Ocean.
18. Analyzing Cultural Features on Topographic Maps
What are the major commercial activities of the area shown on the selected topographic map? How are these activities reflected in the cultural, or human-built, features on the map?
Why do people want to move to this area? Is this a fast or slow-growing, or declining, area, and why? What forces act to limit or promote growth?
Why are certain land uses concentrated in certain areas? For example, what kind of buildings are near railroad tracks? Near stadiums? Near universities? Near interstate highways? Why?
19. Analysis of Scale
Examine scale difference. Obtain different USGS maps of the same area. How large is Lincoln Nebraska on a 1:24,000-scale vs a 1:100,000-scale vs a 1:250,000- scale vs a 1:500,000-scale state base map, and what accounts for this difference?
20. Construct Plaster 3D Models
Construct plaster models of areas on topographic maps. Flood one inch, draw a contour line in marker, flood one more inch, draw another line, etc. Remove water, look at lines from above, to illustrate the concept of contour lines.
21. Analysis of Urbanization Over Time
Examine older vs newer urbanization. How do you know which is older? What are the differences in the street pattern,
and why? Discuss how and why the chosen urban area
first began, and how and why it spread. In which direction(s) is it growing, and why? Was there a river or other physical feature that helped the urban area get its start?
Why is older urbanization usually along straight streets and with smaller homes, vs newer urbanization? Discuss popular culture and consumer preferences.
22. Create Slope Maps
Create slope maps by examining contour lines. Divide the map area into categories and use a symbol identifying the slope in that area. Use a smaller area of the topographic map if the relief is too complex. Use categories 0-5%, 6-10%, etc, or other interval depending on map selected and create polygons where the slope falls within these categories. What is the relationship of land use to slope? What slopes are most human settlements located on?
Obtain USGS Slope map of San Francisco and compare. Does slope influence land use in San Francisco? What slopes are the tall downtown buildings located on, and why?
23. Create Aspect Maps
Make aspect maps by examining contour lines. Aspect refers to the direction (north, east, south, west) that the slope faces. Compare the vegetation on north-facing versus south-facing slopes. What aspects are ski areas usually built on? Why are ski areas usually located on north- facing slopes? Discuss microclimates of slopes.
Where would they be located in the southern hemisphere?
Discuss earth-sun relationships.
24. Analysis of Humans and Hydrography
Discuss floodplains, rivers, and settlement. How do rivers both encourage (with trade and traffic) and discourage (with flooding) settlement? Why does one bank of a large river attract a large city, while the other bank is sparsely populated? This may occur if one bank was higher and flood-free, and the other was flood-prone. What is the elevation of both banks? Discuss the importance of a city site to be on a flood-free site, higher than the floodplain.
25. Site versus Situation
Site refers to the physical attributes of a location, such as tica">drainage, climate, and so on. Situation refers to the advantages and disadvantages of one location over another location, considering trade routes, transportation,and so on.
Discuss site versus situation with topographic maps at different scales.
Examine the New Orleans West, Louisiana 1:24,000-scale map. Note the amount of land below sea level. Discuss draining of the land for a city site on a river delta. Discuss site versus situation here and elsewhere. New Orleans is a poor site (prone to flooding) but has a good situation (near the mouth of a large river). Discuss the impact of global sea level rise on New Orleans. Discuss another location that is a good site but a poor situation (for example, a well-drained location in the middle of plain, far from an overland route or river).
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