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GIS Activities

The following two activities are part of GIS, A New Way to See, an article produced by the Bureau of Land Management (BLM) in cooperation with the National Science Teachers Association (NSTA). It was published in the January 2000 issue of Science & Children magazine, a publication of NSTA. Authors are Melinda Walker, Julie Casper, Frank Hissong, and Elizabeth Rieben The first activity below, Let's Make a Map, is an extension of the article. The second activity, Planning a Campground in Utah, is printed on the back of the poster insert of the article.


Activity One: Let's Make a Map

Activity Two: Planning a Campground in Utah


Let's Make a Map

This activity is designed for upper elementary and middle school teachers and students. In this exercise, students create their own maps, update their maps using new information, and then use their new maps to answer questions about the land.

Three basic images are available - an aerial photo, a grid, and a topographic map. Print these images out on transparent paper to project them for the class, or use the images below in any standard graphics software package where you can add or delete graphics. Another option is to print one of each for students and allow them to draw on the copies. The instructions below assume the teacher is projecting the images for the class and students are following along, drawing their own maps on a piece of paper. The teacher can draw in the additions to the grid on the transparency, or use the map images provided to serve as illustrations of the step-by-step process.


photo
click on image to see a larger version
Grid
grid
click on image to see a larger version

topographic map
topographic map
click on image to see a larger version

First, project the aerial photograph. Tell students that the aerial photograph was taken on May 15, 1992 of the area around Central City, Colorado. Explain to students that Central City was a gold mining town established during the Gold Rush of the mid-1800's. Mining stopped in the 1950's. Ask a student to explain what an aerial photograph is and why aerial photographs are used. (An aerial photo is a picture taken from an airplane that provides information about the land at a large scale - information we cannot see from walking on the ground.) Point out that this photo has pink lines representing boxes of 500 square meters. Now project the grid and point out that the grid has corresponding lines representing 500 meter distances. Then project the third image and explain that this is a portion of the 7.5 minute topographic map of central City produced by the U.S. Geological Survey. It also has the same 500 square meter boxes shown in the first image.


Drawing the map:

1. Project the aerial photo and the grid side by side. Point out that the lines on the photo are not straight up and down. Ask students for ideas why this is so. (Answer: the airplane was not flying due north or south when the photo was taken.) Also, point out that the lines on the photo are not parallel; again, ask the students why this may be. (Answer: the airplane was not flying parallel to the surface of the earth; it was tipped up slightly.)


2. Point out that these conditions are important as they draw their maps. Students will use the grid to transfer information from the photo onto their own maps.


3. First, have students draw the grid and number the boxes as in the illustration below. (For younger students, you may want to have them make the grid lines one inch or two inches apart. Later, they will be calculating scale. It will be easier to calculate if the distance between the lines are not measured in fractions.)

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12

4. Using the photo image as a guide, have them then draw in the two main roads. Then have them do the same for the campground loop road in grid 4 and for the fenced area in grid 9. Explain to students that when the roads and the fenced area are drawn, they are drawn as symbols - something that stands for, or represents, something else. Usually, a thick line is used to represent, or symbolize, a "main" road, while a thin line is used to symbolize a less used road - such as the campground loop road. Ask them to indicate what their symbols mean by including a key or "legend" in one corner of the map. Now their maps should look something like this:


click on image to see a larger version

5. Have the students look at the photo again to try to locate the fence that encloses the area represented on the map in box 9. (Hint: they will not be able to see the fence; the plane was flying at too high an altitude.) Ask the students how they know the fence is there. (Answer: there is a difference in the pattern of vegetation within the fenced area. Different patterns of vegetation also accompany different uses of the land. Vegetation cover associated with cow or sheep grazing will be different from vegetation associated with timber cutting, for example.)


6. Next, have the students take another close look at the photo and find the darkest, rough-textured area. Explain that these are lodgepole pine forests. There also are some aspen mixed in the forest, but they blend in; they cannot be seen on this photo. Ask students how they might be able to determine where these aspen are with a new aerial photograph. (Answer: they could take aerial photographs in the early fall, rather than May, when the leaves would show up as yellow patches on color film.)

7. Now have students take a close look at the pine forests in grids 3, 5 and 7.Aks them if they look different from each other. If so, ask them why they think that could be? (Answer: the pines are growing in different areas with different exposures to sun and wind. For example, the pines in grid 3 grow on a hot, dry, south-facing slope where grasses get the majority of the precipitation. The pines in grid 7 are on a north-facing slope, where there is enough shade and precipitation for lush growth. Grid 5 was "thinned", certain trees have been cut and removed for purposes one cannot tell from the photo. Perhaps they were thinned for a timber sale, to prevent pest infestation, or for fire control. It is harder for a fire to burn when trees are spaced far apart.)

8. Now have students draw in the forested area, starting in grid 7, and continuing through grids 8, 5 and 6. Their maps will look something like this:


click on image to see a larger version

9. Now have students look at the water. Ask them to try to find the five small ponds in the photo. (Hint: open water is very dark and smooth in the photo. There is a long skinny pond at the top of the photo in box 2; a shallow pond, part of a wet area, at the top of box 6; a settling pond next to the mill on the right edge of box 12; and a pond is at the bottom of box 12.) Have them draw these ponds on their maps. Their maps will look like this:


click on image to see a larger version

Updating the map:

Display the topographical map next to the map they have created (or the illustration above). Ask them if they detect any differences between the two. Ask if they can explain why they are different. (The topo map was created in 1979 and the aerial photo was taken thirteen years later in 1992.)


Ask them to look at the topographical map to determine what the fenced in area is that they drew on their maps? (It is a cemetery. Many of the graves in these cemeteries date back to 1850.)

Have them now compare the photo to the topographical map. Ask them to explain the linear feature just west of the cemetery. Ask them to try to explain why it is there? (Answer: the dashed line is a county boundary, so the line feature is probably a fence delineating someone's property. Point out the vegetation pattern just west of the fence; it is either grazed or mowed.)

Ask students what other major change they see. (Answer: trees have been cleared in two areas just east of the campground.)

1. Have students draw in these cleared areas on their maps either by drawing the whole forested area onto their maps and including the cleared areas or drawing just the cleared areas from the topographic map.

2. Now, have them map the wet area along the creek in grid 3. Explain to the students that these riparian zones are important to both plant and animal species. They are also natural filters and improve water quality.


click on image to see a larger version

3. The last update they will make will be to add the power line that starts in box 7, crosses through box 4, through box 5, and meets the road in box 6. Tell students they can "see" the power line because there is a service road beneath it. Ask students if they can guess what characteristic power line roads might have. (Answer: Power line roads differ from regular roads by being very straight lines for very long distances. It is expensive to add towers and "bend" the lines so power lines are always associated with long straight roads.) Only with very tall towers can one actually see a power line in an aerial photograph and even then, only the shadows of the towers can be seen.

Their final map should look something like this:


click on image to see a larger version

Your students have now created a map that represents real features that exist in Central City, Colorado. Now that they have mapped the area, explain to them that they can use the map to learn more about the area.

1. For example, explain that much important map information has to do with distances. Calculating distance is straight-forward once they calculate the scale of the map. Using either a metric or inch ruler, have students measure the distance between the grid lines on their maps. (For younger students, you may want to dictate a scale as they initially draw their grid lines, such as one or two inches.) This distance will represent 500 meters on the ground. Have them divide 500 by the number they measured to get the number of meters per inch or centimeter (For example, if their grid lines are one inch apart, then they would divide 500 by one inch to get 500 meters on the ground. Each inch represents 500 meters. If the distance they measured is two inches, then each inch would represent 250 meters on the ground. If the distance they measured is one and a half inches, it is a little more complicated. Have them divide 500 by one and a half to get about 333 meters, so each inch equals 333 meters. If the distance they measured is one half of an inch, then 500 divided by ½ is 1,000. Each inch equals 1,000 meters,)

Once they have figured their scale, they can then measure distances on the maps they created and calculate the actual distance on the ground. Have them answer the following questions:

What is the length of the power line?

How much of the power line goes through the forest?

How far away is the center of the campground loop from the nearest pond?

Ask them why this might be important to know.
Water quality is always an issue for the health of people and animals. Most management practices have an effect on water. If the latrine at the campground is too close to the pond, the fish might be harmed.

How far away is the campground from the riparian area? From the cemetery? Ask students why this is important to know. Managers will want to build the campground in just the right place, without infringing on a delicate riparian habitat, coming too close to an important cultural site (such as a cemetery), or exposing the campers to undue health hazards (say from a power line).

Have students make up their own questions and try to answer them using the maps.


For more information on maps and mapping, visit the Learning Web at http://www.usgs.gov/education.

For more information about the Bureau of Land Management's environmental education programs and materials, including additional articles produced by the BLM and published in Science & Children magazine, visit the BLM website at http://www.blm.gov/education.

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Last updated: 02-18-2011