Introduction: Contour lines are isolines that connect points of equal elevation.  In topographic maps, mountains are represented as concentric contour lines with equal intervals.  By graphing the contour lines, the profiles of mountains can be rebuilt.

Materials:

- Container of play clay

- Chart paper

- Pencils

- Color markers

- Ruler

- String

- Contour Map Worksheet

- Profile Grid

Note to the Teacher: The following activity can be used in the classroom.  It is also an excellent activity in the lab.  In addition to the materials listed above, you may provide students with wet wipes to clean their hands after the activity.

Do Now/Motivation: Answer the following question in the space below.

1.   What is an isoline?

____________________________________________________________________________________________________________________________

2.   Give some examples of isolines used in different maps.

____________________________________________________________________________________________________________________________

The teacher will validate the answers of the Do Now.

Procedure: Work with your partner.  You will be given a container of play clay.

Step 1: Build your own mountain using 1 container of play clay.

Step 2: Measure the height of your mountain from its base, in centimeters, using a ruler.   

Height of mountain _______ cm.

Divide the height of your mountain by 10.  The length of each segment will be ________ cm.

Step 3: Use the length of each segment you got in step 2 to create equal sections from the base to the top of your play clay-mountain by following these steps:

1. Keep your ruler close to the mountain.  Make sure that your ruler (the centimeter side) touches the base and top of your mountain.

2. You may want to use your pencil to make a mark corresponding to the length of each segment.. 

Length of each segment_=_________________Centimeters

Scale =  ____________  (Express the value of  your segment length in meters)

Step 4: Use a piece of string to cut off the top section. Place it in the rectangle on your worksheet (Appendix 1) and carefully trace its outline.  Now cut the next portion from the top.  Continue cutting and tracing until you have reached the base of the mountain.  By now, you must have traced all the segments of the mountain as a topography map. Mark the peak of your mountain with an X.

Question: What is the name of the map you have got by tracing the mountain?

________________________________________________________________________________________________________________________________

Step 5:  Please put the play clay back into the container, close its lid and clean up your desk.

Step 6: Using a ruler, draw a straight line AB across the concentric contour lines with its end points A and B on the first (base) contour line.  An example is shown below:

Step 7: Keep a strip of paper on the line AB of your contour map and  mark each of  the concentric contour lines as  points with their numerical value on the strip of paper.

Step 8: Mark the Y axis of the profile grid (Appendix 2) using the value of your segment length you got in step 2 from the bottom to the top.

Step 9:  Put the strip of paper at the bottom of the profile grid and mark the points that correspond to the  contour lines of your mountain . Connect the points together to get the profile of the mountain.

Answer the following questions:

1.What kind of contour map did you draw?

 ________________________________________________________________

2.What do close contour lines represent

________________________________________________________________________________________________________________________________

3.What are index contour lines?

________________________________________________________________________________________________________________________________

4. What do hachures represent?

________________________________________________________________________________________________________________________________

 5. How do we determine the direction of flow of a river from a contour map?

________________________________________________________________________________________________________________________________

Assessment:

New York State Standards: 

2.1q Topographic maps represent landforms through the use of contour lines that are isolines connecting points of equal elevation. Gradients and profiles can be determined from changes in elevation over a given distance.