5. From Maps to Models

Summary
Most middle school students have not seen or used topographic maps before. Conceptually, it is difficult for kids to see how a 2 dimensional topo map represents elevation. In this activity, students learn how to create and read topo maps. By the end of the activity, they should be able to read a topo map and identify simple geographical features from a map. Teams of students mold a landform out of clay then place it into a clear plastic container. Water is added to the container in 1 cm intervals and students trace the “shoreline” of their model onto a transparency placed on the box lid. The resulting topo map is traded with another group who is then challenged to turn the 2 dimensional map back into a 3 dimensional landform. Several options are provided for creating the final model based on the materials available to the class. In fact, having more than one option of how to create the model often leads to greater understanding of how topo maps represent elevation.

Objectives
Can understand the construction of topographic maps and the use of contour lines to show the Earth's surface in three dimensions.
Can identify major geographical features on a topographic map.
Can recognize what lines on a topographic map represent.
Can create a topographic map from a 3 dimensional model.
Can create a 3 dimensional model from a topographic map.

Vocabulary
Elevation
Contour line
Topographic map

5. From Maps to Models - Logistics

Time
135-150 minutes (approximately 3 class periods)

Grouping
Teams of 2-4 students (I found this activity works best with groups of 3. Students stay engaged and can get access to the materials, but as a teacher, you don’t need to provide as many sets of materials as with groups of 2.)

Materials
The class needs

• several example topographic maps for students to examine before they begin (see Sources section below)
• optional (though highly recommended) – raised relief map of state or local area (see San Francisco Bay Watershed – Sources for information on where to buy these maps)

For the clay model each group needs
• 1 fist-sized lump of synthetic Plasticine clay (Play-Doh will work, however, it is somewhat water-soluble and therefore becomes slimy after the water box step.)
• 1 small bead of clay of a different color (for marking the top of the mountain)
• 1 half-sheet of transparency film (the sheet of transparency needs to fit inside the plastic container below)

For making the topo map from the model each group needs
• 1 full-sheet of transparency film
• 1 fine-tip Sharpie or overhead marking pen (Permanent pens won’t smudge if a drop of water gets on their map. On the other hand, students can’t make corrections if they make a mistake.)
• 1 plastic shoebox-sized container, at least 8 cm (3 inches) tall (The ones from the Watersheds and Wetlands activity work fine.)
• 1 flat, transparent lid for the plastic container (Most plastic storage containers come with textured, opaque lids. You need something like a sheet a clear Plexiglas that can sit over the top of the box and which students can write on. I recently discovered these plastic salad boxes at Smart and Final that provide a container and a lid in one!)
  

   
• access to a pitcher of water with 4 drops blue food coloring (I had 2 teams share 1 pitcher)
• 1 plastic ruler

For making models from topographic maps each group needs
• 2 copies of a topographic map (1 original and 1 photocopy)
• 1-2 pairs of scissors
• 1 ruler
• 1 fine-tip Sharpie or overhead marking pen
• one of the following:
• 7-8 clear, stacking salad tray tops (available at Smart and Final or other restaurant supply stores)
• 3-4 sheets cardstock paper and a lemon sized ball of clay
• 3-4 sheets of EVA foam
  

   
• 1 fist-sized lump of Plasticine clay

Setting
classroom

5. From Maps to Models - Background

Teacher Background
Topographic maps are often very difficult for middle school students to understand. They are covered in squiggly lines and unfamiliar symbols and bear little resemblance to the road maps and political maps students may be more familiar with. The key is to use models to help students make sense of these maps.

What is a topographic map (or topo map)? These maps provide a way of showing a 3 dimensional landscape on a 2 dimensional surface. The most distinctive features of a topographic map are the contour lines. Each line represents an imaginary line that connects points that are the same elevation above sea level. Thus, if you walk along a contour line, you would not climb up or down, but stay at the same elevation at all times. USGS maps, the standard topographic map, draw contour lines in brown, labeled at intervals with numbers that represent the elevation above sea level or, in the case of bathymetric maps, the elevation below sea level. Other colors you might find on USGS topo maps are green for vegetation, blue for water features, red for major roads, and grey or black for human developments such as smaller roads, railroads and buildings.

Topo maps are used by most often for navigation so that hikers and explorers can get a sense of the terrain. They are also used by scientists to observe things based on their location and their elevation.

Contour lines are spaced at regular intervals (every 10 feet above sea level is marked with a different line for instance). Thus, the closer 2 lines are together, the steeper the area. Hills can be identified by concentric circles that grow smaller and smaller until you reach the peak of a hill. Depressions such as a dried out pond or the crater of a volcano are generally shown with hatched contour lines.

Student Prerequisites
Familiarity with reading other types of maps – political maps, raised relief maps, road maps, etc. – is useful.  I highly recommend Save the Bay’s “Mapping your Watershed” activity that can be downloaded at the bottom of the San Francisco Bay Watershed – Sources section.

5. From Maps to Models - Getting Ready

Getting Ready

• Gather a set of topographic maps for students to examine.
• Display a raised relief map if you have one.
• Gather materials for making clay models: clay and transparency film
• Gather materials for making topo maps from models: transparency film, fine-tip marker, plastic container with clear lid, pitcher of blue water, and ruler
• Gather materials for making models from topo maps: 2 copies of a topo map, scissors, ruler, markers, and one (or more) of the following:
• 7-8 clear, stacking salad tray tops (available at Smart and Final or other restaurant supply stores)
• 3-4 sheets cardstock paper and a lemon sized ball of clay
• 3-4 sheets of EVA foam
• 1 fist-sized lump of Plasticine clay
• You will want to try this activity yourself before you do it with the students. The model you make from the topo map can serve as an example for your students to emulate.

5. From Maps to Models - Lesson Plan

Lesson Plan
Introduction and Making Clay Models

1. Tell students that when we study watersheds it is useful to know how the land dips and rises – where the hills, valleys, ridges, stream beds, and plains are. Most maps don’t tell us this information. They may show cities, roads, and rivers, but not valleys, ridges, and mountains. Tell students that there is a special type of map called a topographic map that does show how the land rises and falls.
2. Give students copies of various topo maps. Ask them what they notice. Have them trace a contour line and tell them what a contour line is. Have them notice how some lines are labeled with the elevation. Have them look for hills by finding concentric circles. Have them look for steep places by finding lots of lines close together and look for flat places by finding lines spaced very far apart. If you have a raised relief map available, help students draw comparisons between the two and see a relationship between these two types of maps. Their understanding will be, and should be, very superficial at this point.
3. Tell students that over the next few days they will be making a model clay island, making a topo map of their island, giving their topo map to another group, and that other group will try to recreate their island using clay or other materials. Divide students into groups.
4. Give each student their first set of materials for making clay models and give them rules for their islands:
   • islands should fit on their transparency
   • islands should have high and low regions such as mountains and valleys
   • islands should not have extremely steep cliffs or overhangs
   • islands should not be too complicated
   • on the highest point of the island, place an “x” using the other color of clay
5. Give students 15-20 minutes to make their islands. Circulate among them making sure they are following the rules. Groups that finish early can add features such as a peninsula near the water, a stream coming down the mountainside, etc.

Making a Topo Map of the Model

1. Using one of your students’ clay models, demonstrate the procedure for making the topo map.
2. Use the marker to label North, South, East and West on the transparency below the clay model.
3. Label the compass points on the large sheet of transparency as well.
4. Place the clay model in the bottom of the plastic container.
5. Place the lid over the container with the transparency on top, oriented the same way (according to the compass points) as the clay model below.
6. Holding your head very still above the lid, trace the shoreline of the island onto the transparency using the marker. Also trace the cross at the top of the tallest hill. This cross will be a reference point to help figure out where to put your head.
7. Remove the lid. Holding a ruler inside the container near the base of the island, pour blue water into the container until the water is 1 cm deep. Notice how the water creates an imaginary line where the elevation above “sea level” is 1 cm all the way around.
8. Replace the lid and the transparency, making sure the transparency is oriented correctly. Match the first coastline and the cross to the island below.
9. Again, holding your head very still, trace the new shoreline of the island – where the water level touches the model. (You can probably end the demonstration here. Students should continue onto the next step.)
10. Repeat adding water and tracing new contour lines until the island is completely submerged.
11. Give students the second set of materials. My students needed 30-45 minutes to create their maps.
12. When all the students are finished, you can assess their understanding so far by placing all the models up at the front of the room and collecting all the maps. Place a map on the overhead projector and look at its features. See if students can tell which model it belongs to. Use features such as the number of hills, distinctive coastlines, valleys, etc. to help students identify which model goes with which map.

Making Models from a Topo Map

1. Make a photocopy of each map. The original map should be left as untouched as possible while the photocopy is a working copy that may be cut up if necessary.
2. Using one of the students’ topo maps, demonstrate how to make a model from a topo map. See the table below:

   Salad Tray Tops	Cardstock Paper	Foam	Clay
   1. Trim the photocopy of the map so that it just fits on the flat bottom of a tray. 2. Trace the outermost contour line onto the first tray. 3. Trace the next contour line onto a second tray and stack it on top of the first. 4. Continue tracing and stacking until all contour lines have been traced.	1. Make a bunch of balls of clay approximately 1 cm tall. 2. On the photocopy of the map, write an “N” on the inside of each contour line on the North side of the island. 3. Hold the photocopy tightly on top of a piece of cardstock. Cut both the photocopy and the cardstock together along the outermost contour line. Label the north side of the cardstock with an N. Set this piece aside. 4. Hold the now smaller photocopy onto a new section of the cardstock and cut out the next contour line and label the north side. Stack this new piece of cardstock on top of the first using some clay balls as spacers to raise it up off the first. 5. Continue cutting out pieces of cardstock and stacking them until all contour lines have been cut out.	1. On the photocopy of the map, write an “N” on the inside of each contour line on the North side of the island. 2. Hold the photocopy tightly on top of a piece of foam. Cut both the photocopy and the foam together along the outermost contour line. Label the north side of the foam with an N. Set this piece aside. 3. Hold the now smaller photocopy onto a new section of the foam and cut out the next contour line and label the north side. Stack this new piece of foam on top of the first, orienting the north sides the same way. 4. Continue cutting out pieces of foam and stacking them until all contour lines have been cut out.	1. Roll out a sheet of clay that is approximately 1 cm thick. Make the sheet as even as possible. 2. Place the photocopy on top of the clay sheet and trace the outermost contour line with a pencil. You should create a shadow of the pencil line on the clay below. 3. Use the pencil, a popsicle stick or fingers to cut the clay along the contour line. 4. Roll out a new clay sheet and trace the next contour line on it. Cut another “pancake” and stack it on top of the first. 5. Continue rolling out, cutting and stacking new clay sheets until all contour lines have been cut out.

    

3. Give each group the original and photocopy of a different group’s topo map as well as the other materials. If you want, have students use the maps to predict what the model will look like before they actually make the model. Allow students 30-45 minutes to create their models.
4. Once all the models have been completed, put the original model, the map, and the second model side by side. Were there any problems? How similar are the two models? How are they different? Why aren’t they exactly the same? Look at the models to discover how different features (hills, valleys, ridges, plateaus, etc.) appear on the maps.
5. If you have time, go back to the example topo maps that were shown at the very beginning of this lesson. See whether students are able to identify elevations, features, and identify trends on the maps now.

 

5. From Maps to Models - Assessments

Assessment


1. Give students a simplified topo map similar to the ones they made and ask them to predict what it would look like in 3 dimensions. Ask them to identify different features: the tallest hill, the steepest part, the flattest part, the elevation of various points, streams, etc.

Going Further

1. Teach students how to create a topographic profile. (See the Geospatial Training and Analysis Cooperative website for detailed instructions for how to do this. Tasa Graphic Arts has a great interactive web tool to illustrate how to make a topographic profile.)
2. Use a topo map in the real world to navigate. Go on a hike with the students and have them identify hills and valleys in the world and orient themselves on a map to figure out where they are and how to get from place to place.

5. From Maps to Models - Sources and Standards

Sources
Activity descriptions and ideas
I first learned how to make topo maps from Eric Muller of the Exploratorium’s Teacher Institute. I changed the method for making the topo map from the models but otherwise our activities are very similar. You can download his "To Topo Two" activity below or from his website with other stellar activities.

USGS has a great description of how to make 3-D model using clear, stacking, salad tray tops.

RAFT describes 2 different ways to create 3-D models. Both are downloadable below or you can access them, and lots of other fabulous idea sheets on the RAFT website. The first “3-D Viewing Topo Lids” uses clear, stacking, salad tray tops. The second, “Making Mountains” uses EVA foam.

If you are an NSTA member, Science Scope had a fabulous article in its October 2005 issue called “Making Sense of Topographic Maps”.

Topographic map information
The best place to learn more about topographic maps is the USGS. For more information about the symbols commonly found on topo maps, see the USGS map symbols page. For more information about how topo maps are created and what they are, see the USGS topo map information page.

Materials
S&S Worldwide has the best deal on EVA foam at $13 for 78 sheets.

Standards
7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will:
f. Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map.