Water Education Poster - Navigation

Navigation Poster for Elementary School Students

Introduction

Locks and dams are necessary structures for safe travel on rivers with shallow water. The upper part of the Mississippi River (north of St. Louis, Missouri) is controlled by 29 dams. Tows and other vessels use locks to navigate around the dams. In this activity, the students use building blocks to simulate elevation changes in a river with dams. A map (aerial) view of the river is compared with the profile, or cross section, of the same stretch of river. A river's profile shows the river surface and bottom, dams, and navigation pools.

Objective-- Students will:

Learn to correlate a river's map view with its side view (profile).

Materials

1. For each group of students and the instructor: 20 rectangular wooden blocks (11 of the blocks should be twice as long as the other 9).
2. Pencil and paper.

Teacher Preparation

1. Display the poster "Navigation: Traveling the Water Highways" several days before conducting this activity. Discuss the importance of locks and dams. Explain the locking through process with the class (see adjacent panel).
2. Divide the students into groups of 3. Separate blocks into sets of 11 long and 9 short blocks for each group and the instructor.

Procedure

1. Instructor: Use the cross-sectional diagram (profile) of the river below to "build" a river channel with four dams out of wooden blocks. Ask the students to observe while the river is built and discuss the four obstacles (dams) that a coal tow would encounter on this river. Explain that the tow must "step" up or down the river where the dams are located. Ask the students to show you where the locks should be constructed. (Answer: parallel to the navigation pool and perpendicular to the dam)
   

   When the river model is finished, ask the students to look at the blocks from the top. Explain to them that they are looking at a map or aerial view of the river. Have the students look at the river from the side. Explain that they are now looking at a profile, or cross section, of the river.

2. Hand out blocks to each group. Ask each group of students to build a river model. Challenge the students to design and construct their own river models. Have each group draw a rough